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Sample records for implant study fact

  1. Implant removal after fracture healing : facts and fiction

    NARCIS (Netherlands)

    Vos, D.I.

    2013-01-01

    A frequently asked question to trauma and orthopaedic surgeons is whether and if yes, when an implant will be removed? Although implant removal after fracture healing is daily practice, a scientific basis doesn’t exist. All studies in this thesis were performed to unravel the facts and fiction of

  2. Ion implantation and annealing studies in III-V nitrides

    International Nuclear Information System (INIS)

    Zolper, J.C.; Pearton, S.J.

    1996-01-01

    Ion implantation doping and isolation is expected to play an enabling role for the realization of advanced III-Nitride based devices. In fact, implantation has already been used to demonstrate n- and p-type doping of GaN with Si and Mg or Ca, respectively, as well as to fabricate the first GaN junction field effect transistor. Although these initial implantation studies demonstrated the feasibility of this technique for the III-Nitride materials, further work is needed to realize its full potential. After reviewing some of the initial studies in this field, the authors present new results for improved annealing sequences and defect studies in GaN. First, sputtered AlN is shown by electrical characterization of Schottky and Ohmic contacts to be an effect encapsulant of GaN during the 1,100 C implant activation anneal. The AlN suppresses N-loss from the GaN surface and the formation of a degenerate n + -surface region that would prohibit Schottky barrier formation after the implant activation anneal. Second, they examine the nature of the defect generation and annealing sequence following implantation using both Rutherford Backscattering (RBS) and Hall characterization. They show that for a Si-dose of 1 x 10 16 cm -2 50% electrical donor activation is achieved despite a significant amount of residual implantation-induced damage in the material

  3. Configuration and mobility of hydrogen implanted in aluminium

    International Nuclear Information System (INIS)

    Bugeat, J.P.; Chami, A.C.; Ligeon, E.

    1976-01-01

    Localization methods through channeling and nuclear reaction analysis using low energy ion beam were applied to the study of deuterium and hydrogen implanted in aluminium single crystals. It was shown that implanted hydrogen occupies a tetrahedral site in the lattice as far as the implantation temperature is lower than 175K. This fact is interpreted by considering an interaction between hydrogen and monovacancies created during the implantation [fr

  4. Moessbauer and TEM study of martensitic transformations in ion implanted 17/7 stainless steel

    International Nuclear Information System (INIS)

    Johnson, E.; Johansen, A.; Sarholt-Kristensen, L.; Graabaek, L.

    1986-01-01

    It has earlier been shown that implantation of antimony into austenitic stainless steels induces martensitic phase transformations γ (fcc)→α (bcc). In the present work we have investigated which mechanisms are responsible for the transformation. Samples of 17/7 steels were implanted with noble gases (Kr, Ar) or the stainless steel constituent elements (Fe, Ni, Cr). The energies were selected to give ranges ∝40 nm. The phases present after implantation and the microstructures of the implanted samples were studied by CEMS and TEM respectively. A martensitic (α) phase was found to form after implantation both with Ni, Fe and Cr, in spite of the fact that these elements have opposite tendencies for stabilization of the austenite (γ) phase. The efficiency of martensite formation is therefore mainly related to stress relief associated with secondary radiation damage. This was substantiated from the noble gas implantations, where the highest degree of transformation was observed for fluences where bubble formation occurs. The CEMS analyses show that the transformation efficiency in such cases is nearly 100%. The hyperfine parameters of the implantation induced α phase are similar to those from conventionally induced martensites. (orig.)

  5. The diagnosis of breast implant rupture

    DEFF Research Database (Denmark)

    Hölmich, Lisbet R; Vejborg, Ilse; Conrad, Carsten

    2005-01-01

    participated in either one or two study MRI examinations, aiming at determining the prevalence and incidence of silent implant rupture, respectively, and who subsequently underwent explantation. Implant rupture status was determined by four independent readers and a consensus diagnosis of either rupture...... were in fact ruptured at surgery. Thirty-four of the 43 intact implants were described as intact at surgery. When categorising possible ruptures as ruptures, there were one false positive and nine false negative rupture diagnoses at MRI yielding an accuracy of 92%, a sensitivity of 89...

  6. Low dose monitoring by double implant technique in IC fabrication

    International Nuclear Information System (INIS)

    Ahmad, I.B.; Weidemann, J.

    1995-01-01

    The utilisation of low dose implant monitoring (using Boron) in a manufacturing line has been discussed. The utilisation of phosphorus ions as the second implant dose were also studied as comparison. The technique relies on the fact that the sheet resistant of doped layer will increase significantly when damaged by relatively low implant dose. The technique is very sensitive and applicable for adjusting the channel dose so that an accurate threshold voltage in MOS device could be achieved

  7. Ion implantation induced conducting nano-cluster formation in PPO

    International Nuclear Information System (INIS)

    Das, A.; Patnaik, A.; Ghosh, G.; Dhara, S.

    1997-01-01

    Conversion of polymers and non-polymeric organic molecules from insulating to semiconducting materials as an effect of energetic ion implantation is an established fact. Formation of nano-clusters enriched with carbonaceous materials are made responsible for the insulator-semiconductor transition. Conduction in these implanted materials is observed to follow variable range hopping (VRH) mechanism. Poly(2,6-dimethyl phenylene oxide) [PPO] compatible in various proportion with polystyrene is used as a high thermal resistant insulating polymer. PPO has been used for the first time in the ion implantation study

  8. Experimental study on bone tissue reaction around HA implants radiated after implantation

    International Nuclear Information System (INIS)

    Kudo, Masato; Matsui, Yoshiro; Tamura, Sayaka; Chen, Xuan; Uchida, Haruo; Mori, Kimie; Ohno, Kohsuke; Michi, Ken-ichi

    1998-01-01

    This study was conducted to investigate histologically and histomorphometrically the tissue reaction around hydroxylapatite (HA) implants that underwent irradiation in 3 different periods in the course of bone healing after implantation. The cylindrical high-density HA implants were implanted in 48 Japanese white rabbit mandibles. A single 15 Gy dose was applied to the mandible 5, 14, or 28 days after implantation. The rabbits were sacrificed 7, 14, 28, and 90 days after irradiation. Nonirradiated rabbits were used as controls. CMR, labeling with tetracycline and calcein, and non-decalcified specimens stained with toluidine blue were used for histological analyses and histomorphometric measurements. The results were as follows: In the rabbits irradiated 5 days after implantation, the HA-bone contact was observed later than that in the controls and the bone-implant contact surface ratio was lower than that in the controls at examination because necrosis of the newly-formed bone occurred just after irradiation. HA-bone contact of the rabbits irradiated 14 and 28 days after implantation was similar to that of the controls. And, bone remodeling was suppressed in rabbits of each group sacrificed at 90 days after irradiation. The results suggested that a short interval between implantation and irradiation causes direct contact between HA implant and bone and a long lapse of time before irradiation hardly affects the bone-implant contact, but delays bone remodeling. Therefore, it is necessary to prevent overloading the HA implants irradiated after implantation and pay utmost attention to conditions around the bone-implant contact. (author)

  9. Implantable Medical Devices; Networking Security Survey

    Directory of Open Access Journals (Sweden)

    Siamak Aram

    2016-08-01

    Full Text Available The industry of implantable medical devices (IMDs is constantly evolving, which is dictated by the pressing need to comprehensively address new challenges in the healthcare field. Accordingly, IMDs are becoming more and more sophisticated. Not long ago, the range of IMDs’ technical capacities was expanded, making it possible to establish Internet connection in case of necessity and/or emergency situation for the patient. At the same time, while the web connectivity of today’s implantable devices is rather advanced, the issue of equipping the IMDs with sufficiently strong security system remains unresolved. In fact, IMDs have relatively weak security mechanisms which render them vulnerable to cyber-attacks that compromise the quality of IMDs’ functionalities. This study revolves around the security deficiencies inherent to three types of sensor-based medical devices; biosensors, insulin pump systems and implantable cardioverter defibrillators. Manufacturers of these devices should take into consideration that security and effectiveness of the functionality of implants is highly dependent on the design. In this paper, we present a comprehensive study of IMDs’ architecture and specifically investigate their vulnerabilities at networking interface.

  10. Evaluation of contiguous implants with cement-retained implant-abutment connections. A minipig study

    Directory of Open Access Journals (Sweden)

    Raquel Rezende Martins de Barros

    2014-03-01

    Full Text Available Aim: The presence of a microgap at the implant-abutment interface may permit bacterial contamination and lead to bone resorption, interfering with papillae formation. The present study evaluated adjacent implants with cement-retained abutments as an option to control such deleterious effects. Materials and methods Seven minipigs had their bilateral mandibular premolars previously extracted. After 8 weeks, four implants were installed in each hemi-mandible of each animal. The adjacent implants were randomly inserted on one side at the crestal bone level and on the other, 1.5 mm subcrestally. Immediately, a non-submerged healing and functional loading were provided with the abutments cementation and prostheses installation. Clinical examination and histomorphometry served to analyze the implant success. Results A total of 52 implants were evaluated at the end of the study. The subcrestal group achieved statistical better results when compared to the crestal group, clinically in papillae formation (1.97 x 1.57 mm and histomorphometrically in crestal bone remodeling (1.17 x 1.63 mm, bone density (52.39 x 45.22% and bone-implant contact (54.13 x 42.46%. Conclusion The subcrestal placement of cement-retained abutment implants showed better indexes of osseointegration and also improved papillae formation and crestal bone remodeling at the interimplant area after immediate loading, making them a promising option for the treatment of esthetic regions.

  11. Impact of Different Surgeons on Dental Implant Failure.

    Science.gov (United States)

    Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

    To assess the influence of several factors on the prevalence of dental implant failure, with special consideration of the placement of implants by different dental surgeons. This retrospective study is based on 2,670 patients who received 10,096 implants at one specialist clinic. Only the data of patients and implants treated by surgeons who had inserted a minimum of 200 implants at the clinic were included. Kaplan-Meier curves were stratified with respect to the individual surgeon. A generalized estimating equation (GEE) method was used to account for the fact that repeated observations (several implants) were placed in a single patient. The factors bone quantity, bone quality, implant location, implant surface, and implant system were analyzed with descriptive statistics separately for each individual surgeon. A total of 10 surgeons were eligible. The differences between the survival curves of each individual were statistically significant. The multivariate GEE model showed the following variables to be statistically significant: surgeon, bruxism, intake of antidepressants, location, implant length, and implant system. The surgeon with the highest absolute number of failures was also the one who inserted the most implants in sites of poor bone and used turned implants in most cases, whereas the surgeon with the lowest absolute number of failures used mainly modern implants. Separate survival analyses of turned and modern implants stratified for the individual surgeon showed statistically significant differences in cumulative survival. Different levels of failure incidence could be observed between the surgeons, occasionally reaching significant levels. Although a direct causal relationship could not be ascertained, the results of the present study suggest that the surgeons' technique, skills, and/or judgment may negatively influence implant survival rates.

  12. Dental implants: A review.

    Science.gov (United States)

    Guillaume, B

    2016-12-01

    A high number of patients have one or more missing tooth and it is estimated that one in four American subjects over the age of 74 have lost all their natural teeth. Many options exist to replace missing teeth but dental implants have become one of the most used biomaterial to replace one (or more) missing tooth over the last decades. Contemporary dental implants made with titanium have been proven safe and effective in large series of patients. This review considers the main historical facts concerned with dental implants and present the different critical factors that will ensure a good osseo-integration that will ensure a stable prosthesis anchorage. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Novel implant design improves implant survival in multirooted extraction sites: a preclinical pilot study.

    Science.gov (United States)

    Sivan-Gildor, Adi; Machtei, Eli E; Gabay, Eran; Frankenthal, Shai; Levin, Liran; Suzuki, Marcelo; Coelho, Paulo G; Zigdon-Giladi, Hadar

    2014-10-01

    The primary aim is to evaluate clinical, radiographic, and histologic parameters of novel implants with "three roots" design that were inserted into fresh multirooted extraction sockets. A secondary aim is to compare this new implant to standard root-form dental implants. Immediate implantation of novel or standard design 6 × 6-mm implants was performed bilaterally into multirooted sockets in mandibles of mini-pigs. Twelve weeks later, clinical, radiographic, stability, histomorphometric, and microcomputed tomography (micro-CT) analyses were performed. Survival rates were significantly higher in the test implants compared with control (92.8% versus 33.3%, respectively; P micro-CT analyses demonstrated bone fill in the inner part of the test implants. Moreover, bone-to-implant contact was higher in the test implants (55.50% ± 3.68% versus 42.47% ± 9.89%). Contrary to the clinical, radiographic, and histomorphometric results, resonance frequency analysis measurements were greater in the control group (77.74 ± 3.21 implant stability quotient [ISQ]) compared with the test group (31.09 ± 0.28 ISQ), P = 0.008. The novel design implants resulted in significantly greater survival rate in multirooted extraction sites. Further studies will be required to validate these findings.

  14. Preservation of keratinized mucosa around implants using a prefabricated implant-retained stent: a case-control study

    OpenAIRE

    Kim, Chang-Soon; Duong, Hieu Pham; Park, Jung-Chul; Shin, Hyun-Seung

    2016-01-01

    Purpose The aim of this study was to clinically assess the impact of a prefabricated implant-retained stent clipped over healing abutments on the preservation of keratinized mucosa around implants after implant surgery, and to compare it with horizontal external mattress sutures. Methods A total of 50 patients were enrolled in this study. In the test group, a prefabricated implant-retained stent was clipped on the healing abutment after implant surgery to replace the keratinized tissue bucco-...

  15. Dental implants in medically complex patients-a retrospective study.

    Science.gov (United States)

    Manor, Yifat; Simon, Roy; Haim, Doron; Garfunkel, Adi; Moses, Ofer

    2017-03-01

    Dental implant insertion for oral rehabilitation is a worldwide procedure for healthy and medically compromised patients. The impact of systemic disease risks on the outcome of implant therapy is unclear, since there are few if any published randomized controlled trials (RCTs). The objective of this study is to investigate the rate of complications and failures following dental implantation in medically compromised patients in order to elucidate risk factors and prevent them. A retrospective cohort study was conducted from patient files treated with dental implantation between the years 2008-2014. The study group consisted of medically complex patients while the control group consisted of healthy patients. Preoperative, intraoperative, and post operative clinical details were retrieved from patients' files. The survival rate and the success rate of the dental implants were evaluated clinically and radiographically. A total of 204 patients (1003 dental implants) were included in the research, in the study group, 93 patients with 528 dental implants and in the control group, 111 patients with 475 dental implants. No significant differences were found between the groups regarding implant failures or complications. The failure rate of dental implants among the patients was 11.8 % in the study group and 16.2 % in the control group (P = 0.04). It was found that patients with a higher number of implants (mean 6.8) had failures compared with patients with a lower number of implants (mean 4.2) regardless of their health status (P dental implantation in medically complex patients and in healthy patients. Medically complex patients can undergo dental implantation. There are similar rates of complications and failures of dental implants in medically complex patients and in healthy patients.

  16. Studies of ion implanted thermally oxidised chromium

    International Nuclear Information System (INIS)

    Muhl, S.

    1977-01-01

    The thermal oxidation of 99.99% pure chromium containing precise amounts of foreign elements has been studied and compared to the oxidation of pure chromium. Thirty-three foreign elements including all of the naturally occurring rare earth metals were ion implanted into chromium samples prior to oxidation at 750 0 C in oxygen. The role of radiation induced damage, inherent in this doping technique, has been studied by chromium implantations at various energies and doses. The repair of the damage has been studied by vacuum annealing at temperatures up to 800 0 C prior to oxidation. Many of the implants caused an inhibition of oxidation, the greatest being a 93% reduction for 2 x 10 16 ions/cm 2 of praseodymium. The distribution of the implant was investigated by the use of 2 MeV alpha backscattering and ion microprobe analysis. Differences in the topography and structure of the chromic oxide on and off the implanted area were studied using scanning electron and optical microscopy. X-ray diffraction analysis was used to investigate if a rare earth-chromium compound of a perovskite-type structure had been formed. Lastly, the electrical conductivity of chromic oxide on and off the implanted region was examined at low voltages. (author)

  17. Angular distributions of sputtered particles from lithium-implanted aluminium and copper crystals

    International Nuclear Information System (INIS)

    Johansen, A.; Johnson, E.; Sarholt-Kristensen, L.; Steenstrup, S.; Andersen, H.H.; Buhanov, V.M.; Chernysh, V.S.; Ivanov, I.N.; Minnebaev, K.F.

    1991-01-01

    The anisotropy of angular distributions of sputtered ions from lithium implanted aluminium and copper single crystals, measured by SIMS analysis, have been used to obtain information about the microstructure of the implanted layers. Sputtered Al + distributions from the {111} surface show three-fold symmetry with maximum intensity near the and directions respectively, while Li + distributions show maximum intensity only in the directions. From {100} crystals the Al + distributions have four-fold symmetry while there are no preferential ejection directions for the Li + ions. This agrees conceptually with the fact that the implanted layer contains the ordered Al 3 Li (δ') phase, which has earlier been observed by TEM analysis on implanted samples. In contrast, a similar study of Li + implanted copper crystals shows that the implanted lithium is randomly located. (orig.)

  18. Tribological studies of ion-implanted steel constituents

    International Nuclear Information System (INIS)

    Wei, Ronghau.

    1990-01-01

    Tribological properties of ion-implanted ferrite and austenite were studied systematically using a unique oscillating pin-on-disc wear tester. Results show that nitrogen implantation at elevated temperatures to high doses dramatically improves the adhesive wear resistance of ferrite and the critical load at which the adhesive wear mechanism changes from mild to severe for austenite. The wear resistance of nitrogen-implanted ferrite is determined by the nitride formed. Extremely hard solid solutions of nitrogen develop on the implanted austenite surfaces and induce three orders of magnitude reductions in wear rates. The implantation conditions that should be used to produce deep, wear-resistant layers for both steels are discussed in detail. Oscillating pin-on-disc wear tests demonstrate that nitrogen does not diffuse during the wearing process although tests conducted using conventional fixed pin-on-disc test equipment could erroneously suggest this occurs. Taken together, the results show that high-dose-rate implantation at low energies yields very-high-quality implanted surfaces at low cost

  19. Effect of healing time on bone-implant contact of orthodontic micro-implants: a histologic study.

    Science.gov (United States)

    Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

    2014-01-01

    Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability.

  20. Public perceptions of dental implants: a qualitative study.

    Science.gov (United States)

    Wang, Guihua; Gao, Xiaoli; Lo, Edward C M

    2015-07-01

    Dental implants have become a popular option for treating partially dentate or edentulous patients. Information on dental implants is widely available in the public domain and is disseminated through industries and dental practitioners at various levels/disciplines. This qualitative study aimed to evaluate the public's information acquisition and their perceptions of dental implants and the effects of these on their care-seeking and decision making. A purposive sample of 28 adults were recruited to join six focus groups. To be eligible, one must be 35-64 years of age, had never been engaged in dentally related jobs, had at least one missing tooth, and had heard about dental implant but never received dental implant or entered into any dental consultation regarding dental implants. All of the focus groups discussions were transcribed verbatim and subjected to thematic content analysis following a grounded theory approach. Participants acquired information on dental implants through various means, such as patient information boards, printed advertisements, social media, and personal connections. They expected dental implants to restore the patients' appearance, functions, and quality of life to absolute normality. They regarded dental implants as a panacea for all cases of missing teeth, overestimated their functions and longevity, and underestimated the expertise needed to carry out the clinical procedures. They were deterred from seeking dental implant treatment by the high price, invasive procedures, risks, and complications. Members of the public were exposed to information of varying quality and had some unrealistic expectations regarding dental implants. Such perceptions may shape their care-seeking behaviours and decision-making processes in one way or another. The views and experiences gathered in this qualitative study could assist clinicians to better understand the public's perspectives, facilitate constructive patient-dentist communication, and contribute

  1. Moessbauer Studies of Implanted Impurities in Solids

    CERN Multimedia

    2002-01-01

    Moessbauer studies were performed on implanted radioactive impurities in semiconductors and metals. Radioactive isotopes (from the ISOLDE facility) decaying to a Moessbauer isotope were utilized to investigate electronic and vibrational properties of impurities and impurity-defect structures. This information is inferred from the measured impurity hyperfine interactions and Debye-Waller factor. In semiconductors isoelectronic, shallow and deep level impurities have been implanted. Complex impurity defects have been produced by the implantation process (correlated damage) or by recoil effects from the nuclear decay in both semiconductors and metals. Annealing mechanisms of the defects have been studied. \\\\ \\\\ In silicon amorphised implanted layers have been recrystallized epitaxially by rapid-thermal-annealing techniques yielding highly supersaturated, electrically-active donor concentrations. Their dissolution and migration mechanisms have been investigated in detail. The electronic configuration of Sb donors...

  2. Magnetoreflection studies of ion implanted bismuth

    International Nuclear Information System (INIS)

    Nicolini, C.; Chieu, T.C.; Dresselhaus, M.S.; Massachusetts Inst. of Tech., Cambridge; Dresselhaus, G.

    1982-01-01

    The effect of the implantation of Sb ions on the electronic structure of the semimetal bismuth is studied by the magnetoreflection technique. The results show long electronic mean free paths and large implantation-induced increases in the band overlap and L-point band gap. These effects are opposite to those observed for Bi chemically doped with Sb. (author)

  3. Comparison of bone-implant contact and bone-implant volume between 2D-histological sections and 3D-SRµCT slices

    Directory of Open Access Journals (Sweden)

    R Bernhardt

    2012-04-01

    Full Text Available Histological imaging is still considered the gold standard for analysing bone formation around metallic implants. Generally, a limited number of histological sections per sample are used for the approximation of mean values of peri-implant bone formation. In this study we compared statistically the results of bone-implant contact (BIC and bone-implant volume (BIV obtained by histological sections, with those obtained by X-ray absorption images from synchrotron radiation micro-computed tomography (SRµCT using osseointegrated screw-shaped implants from a mini-pig study. Comparing the BIC results of 3-4 histological sections per implant sample with the appropriate 3-4 SRµCT slices showed a non-significant difference of 1.9 % (p = 0.703. The contact area assessed by the whole 3D information from the SRµCT measurement in comparison to the histomorphometric results showed a non-significant difference in BIC of 4.9 % (p = 0.171. The amount of the bone-implant volume in the histological sections and the appropriate SRµCT slices showed a non-significant difference by only 1.4 % (p = 0.736 and also remains non-significant with 2.6 % (p = 0.323 using the volumetric SRµCT information. We conclude that for a clinical evaluation of implant osseointegration with histological imaging at least 3-4 sections per sample are sufficient to represent the BIC or BIV for a sample. Due to the fact that in this study we have found a significant intra-sample variation in BIC of up to ± 35 % the selection of only one or two histological sections per sample may strongly influence the determined BIC.

  4. Application of nitrogen plasma immersion ion implantation to titanium nasal implants with nanonetwork surface structure

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ying-Sui; Yang, Wei-En [Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan (China); Zhang, Lan [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Zhu, Hongqin [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Lan, Ming-Ying [Division of Rhinology, Department of Otolaryngology Head and Neck Surgery, Taipei Veterans General Hospital, Taipei 112, Taiwan and School of Medicine, National Yang-Ming University, Taipei 112, Taiwan (China); Lee, Sheng-Wei [Institute of Materials Science and Engineering, National Central University, Taoyuan 320, Taiwan (China); Huang, Her-Hsiung, E-mail: hhhuang@ym.edu.tw [Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan (China); Institute of Oral Biology, National Yang-Ming University, Taipei 112, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung 404, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung 407, Taiwan (China); Department of Bioinformatics and Medical Engineering, Asia University, Taichung 413, Taiwan (China); Department of Stomatology, Taipei Veterans General Hospital, Taipei 112, Taiwan (China)

    2016-07-15

    In nasal reconstruction, the response of cells to titanium (Ti) implants is mainly determined by surface features of the implant. In a pilot study, the authors applied electrochemical anodization to Ti surfaces in an alkaline solution to create a network of nanoscale surface structures. This nanonetwork was intended to enhance the responses of primary human nasal epithelial cell (HNEpC) to the Ti surface. In this study, the authors then treated the anodized, nanonetwork-structured Ti surface using nitrogen plasma immersion ion implantation (NPIII) in order to further improve the HNEpC response to the Ti surface. Subsequently, surface characterization was performed to elucidate morphology, roughness, wettability, and chemistry of specimens. Cytotoxicity, blood, and HNEpC responses were also evaluated. Our results demonstrate that NPIII treatment led to the formation of a noncytotoxic TiN-containing thin film (thickness <100 nm) on the electrochemically anodized Ti surface with a nanonetwork-structure. NPIII treatment was shown to improve blood clotting and the adhesion of platelets to the anodized Ti surface as well as the adhesion and proliferation of hNEpC. This research spreads our understanding of the fact that a TiN-containing thin film, produced using NPIII treatment, could be used to improve blood and HNEpC responses to anodized, nanonetwork-structured Ti surfaces in nasal implant applications.

  5. Microstructural study of hydrogen-implanted beryllium

    International Nuclear Information System (INIS)

    Vagin, S.P.; Chakrov, P.V.; Utkelbayev, B.D.

    1998-01-01

    Hot pressed beryllium (TGP-56) was implanted by 650 keV H + ions to a dose of 6.7 x 10 16 cm -2 at a temperature below 50 C. TEM examinations were performed both at as-irradiated specimens and after post-irradiation annealings at 400-600 C for 15 min. After irradiation, a high density of ''black dot'' defects with a size of about 5 nm is observed in the straggling zone, some of which are resolved as small dislocation loops. During post-irradiation annealing, growth of dislocation loops and oriented gas-filled bubbles are observed in the damaged zone. The bubbles are strongly elongated along the left angle 0001 right angle direction, and their sidelong facts lie along {1-100} planes. These facets have a regular ''toothed'' surface with ''tooth'' facets on {1-100} planes. The size of the ''teeth'' increases with annealing temperature, as well as the total volume of bubbles, with their length growing faster than their width. (orig.)

  6. Aortic Root Enlargement or Sutureless Valve Implantation?

    Directory of Open Access Journals (Sweden)

    Nikolaos G. Baikoussis

    2016-11-01

    Full Text Available Aortic valve replacement (AVR in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM post aortic valve replacement (AVR is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR and the transcatheter valve implantation (TAVI.

  7. Impact of dental implant insertion method on the peri-implant bone tissue: Experimental study

    Directory of Open Access Journals (Sweden)

    Stamatović Novak

    2013-01-01

    Full Text Available Background/Aim. The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. Methods. The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. Results. In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 105, α = 0.05. No necrosis and osteoblastic activity were observed. Conclusion. Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

  8. Physical property of disordered-GaAs produced by ion implantation

    International Nuclear Information System (INIS)

    Nojima, Shunji

    1979-01-01

    The properties of disordered-GaAs produced by ion implantation and its annealing behaviors are investigated for ion species of H, Be, P, and As, from the viewpoints of both the electrical property and the physical structure of the disordered layer. From the study of the electron diffraction for implanted layers and of the conductivity due to defects as a function of dose, depth, measuring temperature, and annealing temperature, the following two facts are clarified: first, the conductivity due to defects can be a good measure for the degree of disorder in GaAs produced by ion implantation, when it is less than --1 Ω -1 cm -1 . Second, the localized states originating from defects are distributed with the same density in the high dose implanted layer, in spite of the degree of disorder in the physical structure. (author)

  9. A prospective, split-mouth study comparing tilted implants with angulated connection versus conventional implants with angulated abutment.

    Science.gov (United States)

    Van Weehaeghe, Manú; De Bruyn, Hugo; Vandeweghe, Stefan

    2017-12-01

    An angulation of the implant connection could overcome the problems related to angulated abutments. This study compares conventional implants with angulated abutment to tilted implants with an angulated connection. Twenty patients were treated in the edentulous mandible. In the posterior jaw locations, one conventional tilted implant with angulated abutment and one angulated implant without abutment were placed. In the anterior jaw, two conventional implants were placed, one with and one without abutment. Implants were immediately loaded and 3 months later, the final bridge (PFM or monolithic zirconia) was placed. After a follow-up of 48 months, 17 patients were available for clinical examination. The mean overall marginal bone loss (MBL) was 1.26 mm. No significant differences in implant survival, MBL, periodontal indices, patients' satisfaction, or complications was found between implants restored on abutment or implant level, between the posteriorly located angulated implant nor angulated abutment, and between both anterior implants with or without abutment. The posterior implants demonstrated less MBL compared to the anterior implants (P abutment were replaced and four loose bridge screws connected to the angulated abutments had to be tightened. Patients were overall satisfied (4.74/5). An implant with angulated connection may results in a stronger connection but does not affect the marginal bone loss. No difference in MBL was seen between implants restored on abutment or implant level. Zirconia seems to reduce the amount of plaque. © 2017 Wiley Periodicals, Inc.

  10. Study of breast implant rupture: MRI versus surgical findings.

    Science.gov (United States)

    Vestito, A; Mangieri, F F; Ancona, A; Minervini, C; Perchinunno, V; Rinaldi, S

    2012-09-01

    This study evaluated the role of breast magnetic resonance (MR) imaging in the selective study breast implant integrity. We retrospectively analysed the signs of breast implant rupture observed at breast MR examinations of 157 implants and determined the sensitivity and specificity of the technique in diagnosing implant rupture by comparing MR data with findings at surgical explantation. The linguine and the salad-oil signs were statistically the most significant signs for diagnosing intracapsular rupture; the presence of siliconomas/seromas outside the capsule and/or in the axillary lymph nodes calls for immediate explantation. In agreement with previous reports, we found a close correlation between imaging signs and findings at explantation. Breast MR imaging can be considered the gold standard in the study of breast implants.

  11. Comparison of surface modified zirconia implants with commercially available zirconium and titanium implants: a histological study in pigs.

    Science.gov (United States)

    Gredes, Tomasz; Kubasiewicz-Ross, Pawel; Gedrange, Tomasz; Dominiak, Marzena; Kunert-Keil, Christiane

    2014-08-01

    New biomaterials and their various surface modifications should undergo in vitro and in vivo evaluation before clinical trials. The objective of our in vivo study was to evaluate the biocompatibility of newly created zirconium implant surfaces after implantation in the lower jaw of pigs and compare the osseointegration of these dental implants with commercially available zirconium and titanium implants. After a healing period of 12 weeks, a histological analysis of the soft and hard tissues and a histomorphometric analysis of the bone-implant contact (BIC) were performed. The implant surfaces showed an intimate connection to the adjacent bone for all tested implants. The 3 newly created zirconium implant surfaces achieved a BIC of 45% on average in comparison with a BIC of 56% from the reference zirconium implants and 35% from titanium implants. Furthermore, the new zirconium implants had a better attachment to gingival and bone tissues in the range of implant necks as compared with the reference implants. The results suggest that the new implants comparably osseointegrate within the healing period, and they have a good in vivo biocompatibility.

  12. Peri-implant and Paracrestal Inflammatory Biomarkers at Failing Versus Surviving Implant Sites in a Beagle Dog Study.

    Science.gov (United States)

    Montero, Javier; Aragón, Fernando; Blanco, Leticia A; Guadilla, Yasmina; García-Cenador, Begona; López-Valverde, Antonio

    This study sought to quantify three biochemical mediators of inflammation (tumor necrosis factor alpha [TNF-α], superoxide anion [SOA], and myeloperoxidase [MPO]) by analyzing crestal (peri-implants) and paracrestal gingival biopsy samples obtained from an experimental study on beagle dogs treated with implants inserted immediately into fresh sockets with circumferential defects. In 10 beagle dogs, 4 roughened titanium implants (3.8 mm wide × 8 mm high) were placed in the distal sockets of the third and fourth premolars, where a circumferential defect (5 mm wide and 5 mm deep) had been previously created by trephination. After varying follow-up periods, ranging from 80 to 190 days, the dogs were explored clinically to assess implant survival, peri-implant pocket depth, and implant stability. The levels of three biochemical mediators of inflammation (MPO, TNF-α, and SOA) were investigated using the crestal and paracrestal gingival biopsy samples with ELISA tests. It was found that 37.5% of the implants were either absent or mobile. Higher levels of the inflammatory mediators were found in the crestal samples than in the paracrestal samples. The final implant stability values were significantly correlated with the final probing depth (r = -0.83, P < .01), but neither of the clinical measures were significantly correlated with any biochemical marker. The risk of implant failure was significantly proportional to the level of MPO (odds ratio: 1.1) and TNF-α (odds ratio: 1.1) in both the crestal and paracrestal regions. All the inflammatory mediators studied were higher in the crestal areas than in the paracrestal regions, but only the values of MPO and TNF-α were significant predictors of implant failure.

  13. A hot implantation study on the evolution of defects in He ion implanted MgO(1 0 0)

    International Nuclear Information System (INIS)

    Fedorov, A.V.; Huis, M.A. van; Veen, A. van

    2002-01-01

    Ion implantation at elevated temperature, so-called hot implantation, was used to study nucleation and thermal stability of the defects. In this work, MgO(1 0 0) single crystal samples were implanted with 30 keV He ions at various implantation temperatures. The implantation doses ranged from 10 14 to 10 16 cm -2 . The implantation introduced defects were subsequently studied by thermal helium desorption spectroscopy (THDS) and Doppler broadening positron beam analysis (PBA). The THDS study provides vital information on the kinetics of He release from the sample. PBA technique, being sensitive to the open volume defects, provides complementary information on cavity evolution. The THD study has shown that in most cases helium release is characterised by the activation energy of Q=4.7±0.5 eV with the maximum release temperature of T max =1830 K. By applying first order desorption model the pre-exponent factor is estimated as ν=4.3x10 11 s -1

  14. Study of the radiation effect in breast implants

    International Nuclear Information System (INIS)

    Moreno T, L. R.; Ramirez R, A.

    2013-01-01

    This breast cancer is one of the most important death causes in women. Among the more frequently medical treatment for advanced breast cancer is the mastectomy. This situation leads to silicone implants as an esthetic option. There have been cases in patients with implants where cancer was frequently detected, in which a conventional radiotherapy is required. In this work is presented a study of the probable adverse effects caused by the application of high power X-rays (6-10 MV) to the silicone implants and to the surrounding tissues. In the research carried out at the clinic, none Bolus effect was detected in patients with implants. Our results prescribe that in the case of patients with implants and frequent breast cancer, the removal of implants is not necessary due radiotherapy works directly in the damaged tissues. (Author)

  15. Study of the radiation effect in breast implants

    Energy Technology Data Exchange (ETDEWEB)

    Moreno T, L. R.; Ramirez R, A., E-mail: lumor2000@yahoo.com.mx [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Departamento de Ciencias Basicas, Av. San Pablo No. 180, Col. Reynosa Tamaulipas, 02200 Mexico D. F. (Mexico)

    2013-10-01

    This breast cancer is one of the most important death causes in women. Among the more frequently medical treatment for advanced breast cancer is the mastectomy. This situation leads to silicone implants as an esthetic option. There have been cases in patients with implants where cancer was frequently detected, in which a conventional radiotherapy is required. In this work is presented a study of the probable adverse effects caused by the application of high power X-rays (6-10 MV) to the silicone implants and to the surrounding tissues. In the research carried out at the clinic, none Bolus effect was detected in patients with implants. Our results prescribe that in the case of patients with implants and frequent breast cancer, the removal of implants is not necessary due radiotherapy works directly in the damaged tissues. (Author)

  16. Comparative Clinical Study of Conventional Dental Implants and Mini Dental Implants for Mandibular Overdentures: A Randomized Clinical Trial.

    Science.gov (United States)

    Aunmeungtong, Weerapan; Kumchai, Thongnard; Strietzel, Frank P; Reichart, Peter A; Khongkhunthian, Pathawee

    2017-04-01

    Dental implant-retained overdentures have been chosen as the treatment of choice for complete mandibular removable dentures. Dental implants, such as mini dental implants, and components for retaining overdentures, are commercially available. However, comparative clinical studies comparing mini dental implants and conventional dental implants using different attachment for implant-retained overdentures have not been well documented. To compare the clinical outcomes of using two mini dental implants with Equator ® attachments, four mini dental implants with Equator attachments, or two conventional dental implants with ball attachments, by means of a randomized clinical trial. Sixty patients received implant-retained mandibular overdentures in the interforaminal region. The patients were divided into three groups. In Groups 1 and 2, two and four mini dental implants, respectively, were placed and immediately loaded by overdentures, using Equator ® attachments. In Group 3, conventional implants were placed. After osseointegration, the implants were loaded by overdentures, using ball attachments. The study distribution was randomized and double-blinded. Outcome measures included changes in radiological peri-implant bone level from surgery to 12 months postinsertion, prosthodontic complications and patient satisfaction. The cumulative survival rate in the three clinical groups after one year was 100%. There was no significant difference (p < 0.05) in clinical results regarding the number (two or four) of mini dental implants with Equator attachments. However, there was a significant difference in marginal bone loss and patient satisfaction between those receiving mini dental implants with Equator attachments and conventional dental implants with ball attachments. The marginal bone resorption in Group 3 was significantly higher than in Groups 1 and 2 (p < 0.05); there were no significant differences between Groups 1 and 2. There was no significant difference in

  17. Tinnitus and Sleep Difficulties After Cochlear Implantation.

    Science.gov (United States)

    Pierzycki, Robert H; Edmondson-Jones, Mark; Dawes, Piers; Munro, Kevin J; Moore, David R; Kitterick, Pádraig T

    To estimate and compare the prevalence of and associations between tinnitus and sleep difficulties in a sample of UK adult cochlear implant users and those identified as potential candidates for cochlear implantation. The study was conducted using the UK Biobank resource, a population-based cohort of 40- to 69-year olds. Self-report data on hearing, tinnitus, sleep difficulties, and demographic variables were collected from cochlear implant users (n = 194) and individuals identified as potential candidates for cochlear implantation (n = 211). These "candidates" were selected based on (i) impaired hearing sensitivity, inferred from self-reported hearing aid use and (ii) impaired hearing function, inferred from an inability to report words accurately at negative signal to noise ratios on an unaided closed-set test of speech perception. Data on tinnitus (presence, persistence, and related distress) and on sleep difficulties were analyzed using logistic regression models controlling for gender, age, deprivation, and neuroticism. The prevalence of tinnitus was similar among implant users (50%) and candidates (52%; p = 0.39). However, implant users were less likely to report that their tinnitus was distressing at its worst (41%) compared with candidates (63%; p = 0.02). The logistic regression model suggested that this difference between the two groups could be explained by the fact that tinnitus was less persistent in implant users (46%) compared with candidates (72%; p reported difficulties with sleep were similar among implant users (75%) and candidates (82%; p = 0.28), but participants with tinnitus were more likely to report sleep difficulties than those without (p explanation is supported by the similar prevalence of sleep problems among implant users and potential candidates for cochlear implantation, despite differences between the groups in tinnitus persistence and related emotional distress. Cochlear implantation may therefore not be an appropriate intervention

  18. Microbial Characteristics of Peri-Implantitis : A Case-Control Study

    NARCIS (Netherlands)

    de Waal, Y C M; Eijsbouts, H V L C; Winkel, E G; van Winkelhoff, A J

    BACKGROUND: Aim of this case-control study was to compare oral microbiological characteristics of subjects with healthy peri-implant conditions and subjects with peri-implantitis and to explore the influence of various patient-related and implant-related factors on the microbiological

  19. Biological effects of N+ ion implantation and UV radiation on streptomyces albus

    International Nuclear Information System (INIS)

    Wu Jian; Dai Guifu

    2005-01-01

    The results of both 30 keV N + ion implantation and UV irradiation of Streptomyces albus showed complicate biological effects. The 'saddle shape' pattern of the dose-dependent curve formed by N + ion implantation with low energy was studied, and it proved that vacuum was not the reason, and the fact, the 'saddle shape' curve may be regarded as a HRS/IRR (hyper-radiosensitivity/increased radiaoresistance) effect caused by low dose irradiation. But Streptomyces albus UV irradiated after vacuum treatment only showed IRR effect or hormesis (survival rate >100%). The streptomycin resistance mutation of Streptomyces albus caused by low energy N + ion implantation and UV irradiation was also studied. the results showed that UV radiation is one effective means for streptomyces albus breeding. (authors)

  20. Cone-morse implant connection system significantly reduces bacterial leakage between implant and abutment: an in vitro study.

    Science.gov (United States)

    Baj, A; Bolzoni, A; Russillo, A; Lauritano, D; Palmieri, A; Cura, F; Silvestre, F J; Giannì, A B

    2017-01-01

    Osseointegrated implants are very popular dental treatments today in the world. In osseointegrated implants, the occlusal forces are transmitted from prosthesis through an abutment to a dental implant. The abutment is connected to the implant by mean of a screw. A screw is the most used mean for connecting an implant to an abutment. Frequently the screws break and are lost. There is an alternative to screw retained abutment systems: the cone-morse connection (CMC). The CMC, thanks to the absence of the abutment screw, guarantees no micro-gaps, no micro-movements, and a reduction of bacterial leakage between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new CMC implants systems (Leone Spa®, Florence, Italy). To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Four cone-morse Leone implants (Leone® Spa, Florence, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was then measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 3% for P. gingivalis and 4% for T. forsythia. Cone-morse connection implant system has very low bacterial leakage percentage and is similar to one-piece implants.

  1. Early Healing Events around Titanium Implant Devices with Different Surface Microtopography: A Pilot Study in an In Vivo Rabbit Model

    Directory of Open Access Journals (Sweden)

    Ester Orsini

    2012-01-01

    Full Text Available In the present pilot study, the authors morphologically investigated sandblasted, acid-etched surfaces (SLA at very early experimental times. The tested devices were titanium plate-like implants with flattened wide lateral sides and jagged narrow sides. Because of these implant shape and placement site, the device gained a firm mechanical stability but the largest portion of the implant surface lacked direct contact with host bone and faced a wide peri-implant space rich in marrow tissue, intentionally created in order to study the interfacial interaction between metal surface and biological microenvironment. The insertion of titanium devices into the proximal tibia elicited a sequence of healing events. Newly formed bone proceeded through an early distance osteogenesis, common to both surfaces, and a delayed contact osteogenesis which seemed to follow different patterns at the two surfaces. In fact, SLA devices showed a more osteoconductive behavior retaining a less dense blood clot, which might be earlier and more easily replaced, and leading to a surface-conditioning layer which promotes osteogenic cell differentiation and appositional new bone deposition at the titanium surface. This model system is expected to provide a starting point for further investigations which clarify the early cellular and biomolecular events occurring at the metal surface.

  2. PIP breast implant removal: a study of 828 cases.

    Science.gov (United States)

    Oulharj, S; Pauchot, J; Tropet, Y

    2014-03-01

    In March, 2010, the French Health Products Safety Agency suspended the sale of prefilled silicone breast implants manufactured by Poly Implants Prosthèse Prothese (PIP) because of a high failure rate and the use of an inappropriate silicone gel that did not comply with CE marking. These findings led to an international medical crisis. In France, 30,000 female patients had PIP implants. In our Department, 1150 PIP breast implants had been implanted in 630 patients since 2001. A retrospective study was conducted to define the rupture rate of these implants and the complications that arise. The women included in the study underwent implant removal from May 2010 to September 2012 for preventive or curative reasons. Data were collected from medical records that included: results of clinical examination, breast ultrasound before removal, rates of implant rupture, results of biopsy of periprosthetic capsule and pericapsule tissue and postoperative complications. A total of 828 PIP breast implants were removed in 455 patients. The rate of ruptured implants was 7.73% (64/828), corresponding to 11.6% of patients. A periprosthetic effusion was associated with rupture in 44% of cases. Breast ultrasound indicated a rupture for 87 implants; 32% were true positives and 3% were false negatives. Periprosthetic capsule biopsy demonstrated the presence of a foreign body, which seemed to be silicone, in 26% of cases and the presence of inflammation in 13% of cases. No siliconoma-type lesion was identified in the pericapsular tissue at biopsy. A total of 14 implants presented perspiration at removal. A statistically significant difference was found between the rates of rupture for texturised implants as compared to the smooth-surfaced implants. There were eight post-revisional-surgery complications (1%) and three cases of breast adenocarcinoma. The preventive explantation of PIP breast implants is justified given the high failure rate (7.73%) and given patients' exposure to silicone

  3. Immediately loaded mini dental implants as overdenture retainers: 1-Year cohort study of implant stability and peri-implant marginal bone level.

    Science.gov (United States)

    Šćepanović, Miodrag; Todorović, Aleksandar; Marković, Aleksa; Patrnogić, Vesna; Miličić, Biljana; Moufti, Adel M; Mišić, Tijana

    2015-05-01

    This 1-year cohort study investigated stability and peri-implant marginal bone level of immediately loaded mini dental implants used to retain overdentures. Each of 30 edentulous patients received 4 mini dental implants (1.8 mm × 13 mm) in the interforaminal mandibular region. The implants were immediately loaded with pre-made overdentures. Outcome measures included implant stability and bone resorption. Implant stability was measured using the Periotest Classic(®) device immediately after placement and on the 3rd and 6th weeks and the 4th, 6th and 12th months postoperatively. The peri-implant marginal bone level (PIBL) was evaluated at the implant's mesial and distal sides from the polished platform to the marginal crest. Radiographs were taken using a tailored film holder to reproducibly position the X-ray tube at the 6th week, 4th and 12th months postoperatively. The primary stability (Periotest value, PTV) measured -0.27 ± 3.41 on a scale of -8 to + 50 (lower PTV reflects higher stability). The secondary stability decreased significantly until week 6 (mean PTV = 7.61 ± 7.05) then increased significantly reaching (PTV = 6.17 ± 6.15) at 12 months. The mean PIBL measured -0.40 mm after 1 year of functional loading, with no statistically significant differences at the various follow-ups (p = 0.218). Mini dental implants placed into the interforaminal region could achieve a favorable primary stability for immediate loading. The follow-up Periotest values fluctuated, apparently reflecting the dynamics of bone remodeling, with the implants remaining clinically stable (98.3%) after 1 year of function. The 1-year bone resorption around immediately loaded MDIs is within the clinically acceptable range for standard implants. Copyright © 2014 Elsevier GmbH. All rights reserved.

  4. Spontaneous progression of ligature induced peri-implantitis at implants with different surface roughness: an experimental study in dogs

    DEFF Research Database (Denmark)

    Berglundh, T; Gotfredsen, K; Zitzmann, N U

    2007-01-01

    : The aim of the current experiment was to study the progression of peri-implantitis around implants with different surface roughness. MATERIAL AND METHODS: In five beagle dogs, three implants with either a sandblasted acid-etched surface (SLA) or a polished surface (P) were installed bilaterally......BACKGROUND: Peri-implantitis is associated with the presence of submarginal plaque, soft-tissue inflammation and advanced breakdown of the supporting bone. The progression of peri-implantitis following varying periods of continuing plaque accumulation has been studied in animal models. OBJECTIVE...... in the edentulous premolar regions. After 3 months on a plaque control regimen, experimental peri-implantitis was induced by ligature placement and plaque accumulation was allowed to progress until about 40% of the height of the supporting bone had been lost. After this 4-month period, ligatures were removed...

  5. Osseointegrated implants and auricular defects: a case series study.

    Science.gov (United States)

    Wright, Robert F; Zemnick, Candice; Wazen, Jack J; Asher, Eric

    2008-08-01

    The objective of this study was to report on the survival rate of 16 patients treated with extraoral implants in the auricular region, analyze treatment outcomes, and discuss important clinical variables encountered during treatment. Sixteen patients who received extraoral dental implants to retain auricular prostheses between 1987 and 2003 were followed retrospectively. The variables recorded were gender, initial diagnosis, number and size of implants, implant placement date, age at implant placement, history of radiation to the treated field, abutment size, design of initial prosthesis, age of initial prosthesis (when a remake was indicated), date of prosthesis delivery, soft tissue response, grafting procedure, date of last follow-up, and complications. All patients were thoroughly evaluated presurgically by the reconstruction team, which consisted of prosthodontists, a facial prosthetist, and an otolaryngologist. Surgical templates were used for all patients. The criteria for success of the prostheses included marginal accuracy, overall stability and function, symmetry/position, texture, color stability, and patient acceptance. Thirty-nine implants were placed in 16 patients. All 16 patients were completely satisfied with their reconstructions. No surgical complications, implant failures, or prosthetic failures were encountered. Therefore, the survival rate was 100%. Three patients (18.75%) had grade 0, seven (43.75%) had grade 1, five (31.25%) had grade 2, and one (6.25%) had grade 3 soft tissue inflammation. The inflammation completely resolved in 7 of the 13 patients (54%) with hygiene reinforcement or soft tissue reduction. The survival rate for bone-anchored titanium implants and prostheses was 100%. Bone-anchored titanium implants provided the 16 patients in this study with a safe, reliable, adhesive-free method to anchor auricular prostheses with recovery of normal appearance. Under the guidance of an appropriate implant team, proper positioning of

  6. Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study

    Science.gov (United States)

    AUNMEUNGTONG, W.; KHONGKHUNTHIAN, P.; RUNGSIYAKULL, P.

    2016-01-01

    SUMMARY Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Materials and methods Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. Results There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Conclusions Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Clinical implications Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant

  7. Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study.

    Science.gov (United States)

    Aunmeungtong, W; Khongkhunthian, P; Rungsiyakull, P

    2016-01-01

    Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant should exhibit the same behavior to chewing force.

  8. Preservation of keratinized mucosa around implants using a prefabricated implant-retained stent: a case-control study

    Science.gov (United States)

    2016-01-01

    Purpose The aim of this study was to clinically assess the impact of a prefabricated implant-retained stent clipped over healing abutments on the preservation of keratinized mucosa around implants after implant surgery, and to compare it with horizontal external mattress sutures. Methods A total of 50 patients were enrolled in this study. In the test group, a prefabricated implant-retained stent was clipped on the healing abutment after implant surgery to replace the keratinized tissue bucco-apically. In the control group, horizontal external mattress sutures were applied instead of using a stent. After the surgical procedure, the width of the buccal keratinized mucosa was measured at the mesial, middle, and distal aspects of the healing abutment. The change in the width of the buccal keratinized mucosa was assessed at 1 and 3 months. Results Healing was uneventful in both groups. The difference of width between baseline and 1 month was −0.26±0.85 mm in the test group, without any statistical significance (P=0.137). Meanwhile, the corresponding difference in the control group was −0.74±0.73 mm and it showed statistical significance (Pprefabricated implant-retained stent was shown to be effective in the preservation of the keratinized mucosa around implants and it was simple and straightforward in comparison to the horizontal external mattress suture technique. PMID:27800215

  9. What's really behind the attack on silicone breast implants.

    Science.gov (United States)

    Angell, M

    1996-09-09

    Millions of dollars are being awarded by injuries and a major company has been forced into bankruptcy because of litigation over silicone breast implants. Yet scientific research hasn't established a link between the implants and disease, notes Marcia Angell, executive editor of the New England Journal of Medicine. When she began studying the issue, this self-described feminist and liberal Democrat expected to uncover iniquities of big business and the implant manufacturers. Instead, she's written an indictment of the tort system, junk science, and the gullibility of the news media. Attorneys have twisted facts and played on the emotions of juries, with the consent of judges and often to the cheers of the press. Angell worries that it's now become politically correct to bash the scientific method in the name of diversity, multiculturalism, and feminism.

  10. Evaluation of Satisfaction Level in Patients With Mandibular Implant Supported Overdentures

    Directory of Open Access Journals (Sweden)

    Masoumeh khoshhal

    2016-01-01

    Full Text Available Background Implant-supported overdentures could have many benefits for patients, especially in the lower jaws. As a matter of fact, the most common reason for prescribing mandibular overdenture is dissatisfaction of patients with mandibular dentures usually because of a lack of retention, stability and function and speech difficulties. On the other hand, patients' expectations of overdenture treatments are their main disadvantage. Objectives The aim of this study was to evaluate the satisfaction of patients who had received mandibular implant supported overdenture treatment with different number of implants. Patients and Methods This study was a descriptive cross-sectional study. Twenty-five patients with a mean age of 62.7 years who had received mandibular implant supported overdenture treatment at the dental school of Hamadan University of Medical Sciences were enrolled. Among these patients, six had overdentures supported by one implant, nine had overdentures supported by two implants, two had overdentures supported by three implants, five had overdentures supported by four implants and three had overdentures supported by five implants. The visual analogue scale (VAS questionnaire was used to evaluate the general satisfaction, comfort, esthetic, fitness, satisfaction of chewing and social communication, and the data was analyzed by the analysis of variance (ANOVA test. Results All patients in all five groups were satisfied with their overdentures; however there was no significant relationship between the number of implants and fitness (P = 0.446, esthetic (P = 0.843, comfort (P = 0.805, satisfaction of chewing (P = 0.133, social communication (P = 0.322 and general satisfaction (P = 0.493. Conclusions There was no difference in satisfaction level of patients who had received mandibular overdentures with different number of implants.

  11. Role of clinician's experience and implant design on implant stability. An ex vivo study in artificial soft bones.

    Science.gov (United States)

    Romanos, Georgios E; Basha-Hijazi, Abdulaziz; Gupta, Bhumija; Ren, Yan-Fang; Malmstrom, Hans

    2014-04-01

    Clinical experience in implant placement is important in order to prevent implant failures. However, the implant design affects the primary implant stability (PS) especially in poor quality bones. Therefore, the aim of this study was to compare the effect of clinician surgical experience on PS, when placing different type of implant designs. A total of 180 implants (90 parallel walled-P and 90 tapered-T) were placed in freshly slaughtered cow ribs. Bone quality was evaluated by two examiners during surgery and considered as 'type IV' bone. Implants (ø 5 mm, length: 15 mm, Osseotite, BIOMET 3i, Palm Beach Gardens, FL, USA) were placed by three different clinicians (master/I, good/II, non-experienced/III, under direct supervision of a manufacturer representative; 30 implants/group). An independent observer assessed the accuracy of placement by resonance frequency analysis (RFA) with implant stability quotient (ISQ) values. Two-way analysis of variance (ANOVA) and Tukey's post hoc test were used to detect the surgical experience of the clinicians and their interaction and effects of implant design on the PS. All implants were mechanically stable. The mean ISQ values were: 49.57(± 18.49) for the P-implants and 67.07(± 8.79) for the T-implants. The two-way ANOVA showed significant effects of implant design (p bone. © 2012 Wiley Periodicals, Inc.

  12. Randomized study on the effect of single-implant versus two-implant retained overdentures on implant loss and muscle activity: a 12-month follow-up report.

    Science.gov (United States)

    Alqutaibi, A Y; Kaddah, A F; Farouk, M

    2017-06-01

    The objective was to evaluate and compare single- and two-implant retained overdentures for the rehabilitation of the edentulous mandible. Fifty-six edentulous subjects were eligible for inclusion. Using a random sampling system, a single implant or two implants were placed in the mandible. After 3 months, locator attachments were connected to the implants and the denture delivered with the retentive components incorporated in the denture base. Implant failure and muscle activity were evaluated at the 3-, 6-, and 12-month follow-up examinations. The study sample comprised 56 patients (32 male, 24 female), with a mean age of 58.2 years. A total of 84 implants were placed (28 in the single-implant group and 56 in the two-implant group). All patients completed the 12 months of follow-up. No significant differences were found between subjects in the two groups with respect to implant failure. With regard to improvements in muscle activity, the two-implant group showed statistically significant but perhaps not clinically important differences. Single-implant mandibular overdentures may be suggested as an alternative treatment modality for the rehabilitation of edentulous patients who cannot afford the cost of a two-implant overdenture. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. Effect of fluence on the lattice site of implanted Er and implantation induced strain in GaN

    CERN Document Server

    Wahl, U; Decoster, S; Vantomme, A; Correi, J G

    2009-01-01

    A GaN thin film was implanted with 5 × 1014 cm−2 of 60 keV stable 166Er, followed by the implantation of 2 × 1013 cm−2 radioactive 167Tm (t1/2 = 9.3 d) and an annealing sequence up to 900 °C. The emission channeling (EC) technique was applied to assess the lattice location of Er following the Tm decay from the conversion electrons emitted by 167mEr, which showed that more than 50% of 167mEr occupies substitutional Ga sites. The results are briefly compared to a 167mEr lattice location experiment in a GaN sample not pre-implanted with 166Er. In addition, high-resolution X-ray diffraction (HRXRD) was used to characterize the perpendicular strain in the high-fluence implanted film. The HRXRD experiments showed that the Er implantation resulted in an increase of the c-axis lattice constant of the GaN film around 0.5–0.7%. The presence of significant disorder within the implanted region was corroborated by the fact that the EC patterns for off-normal directions exhibit a pronounced angular broadening of t...

  14. Patients' perceptions of implant placement surgery, the post-surgical healing and the transitional implant prostheses: a qualitative study.

    Science.gov (United States)

    Kashbour, Wafa A; Rousseau, Nikki; Thomason, J Mark; Ellis, Janice S

    2017-07-01

    This study aimed to explore patients' thoughts, feelings about, and experiences of, implant placement surgery (IPS), the post-surgical healing stage and the immediate post-surgical transitional implant prosthesis (TIP) (fixed and removable). A qualitative study design was chosen and 38 semi-structured telephone and face-to-face interviews were conducted with 34 patients at different stages of implant treatment. The interviews were transcribed verbatim; the data collection and coding process followed the principles of thematic analysis, which was facilitated through the use of NVivo10. Patients anticipated that surgery would be painful and unpleasant but were prepared to accept this temporary discomfort for the expected benefits of implant treatment. However, a key finding was that patients felt they had overestimated the trauma of surgery but underestimated the discomfort and difficulties of the healing phase. A number of difficulties were also identified with the TIP phase following implant surgery. Existing research has tended to focus on the longer term benefits of dental implant treatment. This qualitative study has investigated in-depth patients' perceptions of dental implant surgery, including their experiences related to sedation, and of transitional implant restoration. While patients felt their concerns were overestimated in relation to the implant surgery, they experienced greater morbidity than they expected in the healing phase. Recommendations are made for relatively small changes in care provision which might improve the overall patient experience. Partial dentate patients treated with a fixed transitional prosthesis experienced advantages more quickly than patients with an overdenture. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Martensitic transformations in 304 stainless steel after implantation with helium, hydrogen and deuterium

    International Nuclear Information System (INIS)

    Johnson, E.; Grabaek, L.; Johansen, A.; Sarholt-Kristensen, L.; Hayashi, N.; Sakamoto, I.

    1988-01-01

    Using conversion electron Moessbauer spectroscopy (CEMS) and glancing angle X-ray diffraction, martensitic transformations have been studied in type 304 austenitic stainless steels implanted with 8 keV helium, hydrogen and deuterium. Furthermore, using CEMS in the energy selective mode (DCEMS), the distribution of martensite in the implantation zone has been analysed as a function of depth. Transformation of the implanted layer occurs after implantation with 10 21 m -2 He + ions while 100 times higher fluence is required for the implanted layer to transform after hydrogen or deuterium implantations. This difference is due to the ability of helium to form high pressure gas bubbles, while implanted hydrogen is continuously lost by back diffusion to the surface. The helium bubbles, which are confined under pressures as high as 60 GPa, will induce extremely high stress levels in the implanted layer, by which the martensitic transformation is directly induced. The fact that a much higher fluence of hydrogen or deuterium is required to induce the transformation, shows that radiation damage plays only a minor role. In this case, the martensitic transformation first occurs when the implanted layer resembles the state of a cathodically charged surface. (orig.)

  16. Influence of simulated bone-implant contact and implant diameter on secondary stability: a resonance frequency in vitro study.

    Science.gov (United States)

    Veltri, Mario; González-Martín, Oscar; Belser, Urs C

    2014-08-01

    This study tested the hypothesis of no differences in resonance frequency for standardized amounts of simulated bone-implant contact around implants with different diameters. In addition, it was evaluated if resonance frequency is able to detect a difference between stable and rotation mobile ("spinning") implants. Implants with diameters of 3.3, 4.1 and 4.8 mm were placed in a purposely designed metal mould where liquid polyurethane resin was then poured to obtain a simulated bone-implant specimen. By regulating the mould, it was possible to create the following simulated bone-implant contact groups: 3.3 mm (198.6 mm(2)); 4.1 mm (198.8 mm(2)); 4.8 mm (200.2 mm(2)); 4.8 mm (231.7 mm(2)); 4.8 mm (294.7 mm(2)). Each group included 10 specimens. After resin setting, resonance frequency was measured. On the last group, measurements were repeated after establishing implant rotational mobility. One-way ANOVA tests with post hoc comparisons, a Pearson's correlation coefficient and a t-test for repeated measurements were used to evaluate statistically significant differences. Implants with different diameters but with the same amount of simulated osseointegration revealed no differences in resonance frequency. On the contrary, an increase of simulated bone-implant contact resulted in significantly higher resonance frequency. A clear direct linear correlation resulted between resonance frequency and simulated bone-implant contact. Furthermore, a significant difference resulted between resonance frequency measured before and after creation of rotational mobility. Within the conditions of this study, the secondary stability was correlated with the simulated bone-implant contact. In addition, resonance frequency was able to discern between stable and rotation mobile implants. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. A 10-year randomized clinical trial on the influence of splinted and unsplinted oral implants retaining mandibular overdentures: peri-implant outcome.

    Science.gov (United States)

    Naert, Ignace; Alsaadi, Ghada; van Steenberghe, Daniel; Quirynen, Marc

    2004-01-01

    This randomized controlled clinical trial aimed to evaluate the efficacy of splinted implants versus unsplinted implants in overdenture therapy over a 10-year period. The study sample comprised 36 completely edentulous patients, 17 men and 19 women (mean age 63.7 years). In each patient, 2 implants (Brånemark System, Nobel Biocare, Göteborg, Sweden) were placed in the interforaminal area. Three to 5 months after placement, they were connected to standard abutments. The patients were then rehabilitated with ball-retained overdentures, magnet-retained overdentures, or bar-retained overdentures (the control group). Patients were followed for 4, 12, 60, and 120 months post-abutment connection. Group means as well as linear regression models were fitted with attachment type and time as classification variables and corrected for simultaneous testing (Tukey). After 10 years, 9 patients had died and 1 was severely ill. Over 10 years, no implants failed. Mean Plaque Index, Bleeding Index, change in attachment level, Periotest values, and marginal bone level at the end of the follow-up period were not significantly different among the groups. The annual marginal bone loss, excluding the first months of remodeling, was comparable with that found around healthy natural teeth. The fact that no implants failed and that overall marginal bone loss after the first year of bone remodeling was limited suggested that implants in a 2-implant mandibular overdenture concept have an excellent prognosis in this patient population, irrespective of the attachment system used.

  18. Ion implantation

    International Nuclear Information System (INIS)

    Dearnaley, Geoffrey

    1975-01-01

    First, ion implantation in semiconductors is discussed: ion penetration, annealing of damage, gettering, ion implanted semiconductor devices, equipement requirements for ion implantation. The importance of channeling for ion implantation is studied. Then, some applications of ion implantation in metals are presented: study of the corrosion of metals and alloys; influence or ion implantation on the surface-friction and wear properties of metals; hyperfine interactions in implanted metals

  19. Trabeculectomy with Ex-PRESS implant versus Ahmed glaucoma valve implantation-a comparative study

    Science.gov (United States)

    Waisbourd, Michael; Fischer, Naomi; Shalev, Hadas; Spierer, Oriel; Ben Artsi, Elad; Rachmiel, Rony; Shemesh, Gabi; Kurtz, Shimon

    2016-01-01

    AIM To compare the surgical outcomes of trabeculectomy with Ex-PRESS implant and Ahmed glaucoma valve (AGV) implantation. METHODS Patients who underwent trabeculectomy with Ex-PRESS implants or AGV implantation separately were included in this retrospective chart review. Main outcome measures were surgical failure and complications. Failure was defined as intraocular pressure (IOP) >21 mm Hg or glaucoma, or loss of light perception. Eyes that had not failed were considered as complete success if they did not required supplemental medical therapy. RESULTS A total of 64 eyes from 57 patients were included: 31 eyes in the Ex-PRESS group and 33 eyes in the AGV group. The mean follow-up time was 2.6±1.1y and 3.3±1.6y, respectively. Patients in the AGV group had significantly higher baseline mean IOP (P=0.005), lower baseline mean visual acuity (VA) (P=0.02), and higher proportion of patients with history of previous trabeculectomy (Pglaucoma surgeries. Therefore, the results are limited to the cohort included in this study. PMID:27803857

  20. On the blister formation in copper alloys due to the helium ion implantation

    International Nuclear Information System (INIS)

    Moreno, D.; Eliezer, D.

    1997-01-01

    Structural materials in fusion reactors will be exposed to alpha radiation and helium implantation over a broad range of energies. A new approach to the blister-formation phenomenon is discussed by means of the mathematical solution on a uniformly loaded circular plate with clamped edges (circular diaphragm). In the present investigation, it was found that blister formation depends on the mechanical properties of the alloys and the near-surface concentration of the implanted gas, which itself is contingent on the crystallographic orientation by means of the stopping power of the implanted atoms. The reported model is based on the fact that at certain depths from the surface, the pressure in the cavities approaches the yield stress of the metal and blistering starts. The thickness of this thin film depends on the mechanical properties of the specific metal. Once a blister cavity is formed, the deformation of the thin film to form a blister cap depends on the buildup of pressure in the cavity contingent on the implanted dose. For the present model, it is sufficient to say that the thickness of the blister's cap cannot be correlated with the projected range of the implantation, as assumed by other authors. The implanted helium concentration needed to build up enough gas pressure to create a blister at a depth which is close to the projected range is higher by 50 times than the gas helium concentration in the cavity. Experimental results, such as the fact that the blisters have burst at the edge of the circular skin, where the maximum stresses are developed, and the fact that at high implantation energy (large projected range), the bursting of the blisters occurs by multilayer caps, support the present model

  1. Amorphous GaP produced by ion implantation

    International Nuclear Information System (INIS)

    Shimada, T.; Kato, Y.; Shiraki, Y.; Komatsubara, K.F.

    1976-01-01

    Two types of non-crystalline states ('disordered' and 'amorphous') of GaP were produced by using ion implantation and post annealing. A structural-phase-transition-like annealing behaviour from the 'disordered' state to the 'amorphous' state was observed. The ion dose dependence and the annealing behaviour of the atomic structure of GaP implanted with 200 keV -N + ions were studied by using electron diffraction, backscattering and volume change measurements. The electronic structure was also investigated by measuring optical absorption and electrical conductivity. The implanted layer gradually loses the crystalline order with the increase of the nitrogen dose. The optical absorption coefficient α and electric conductivity sigma of GaP crystals implanted with 200 keV -N + ions of 1 x 10 16 cm -2 were expressed as αhν = C(hν - E 0 )sup(n) and log sigma = A -BTsup(-1/4), respectively. Moreover, the volume of the implanted layer increased about three percent and the electron diffraction pattern was diffused halo whose intensity monotonically decreases along the radial direction. These results indicate that the as-implanted layer has neither a long range order or short range order ('disordered state'). In the sample implanted at 1 x 10 16 cm -2 , a structural phase-transition-like annealing stage was observed at around 400 0 C. That is, the optical absorption coefficient abruptly fell off from 6 x 10 4 to 7 x 10 3 cm -1 and the volume of the implanted layer decreased about 2% within an increase of less than 10 degrees in the anneal temperature. Moreover, the short range order of the lattice structure appeared in the electron diffraction pattern. According to the backscattering experiment, the heavily implanted GaP was still in the non-crystalline state even after annealing. These facts suggest that heavily implanted GaP, followed by annealing at around 400 0 C, is in the 'amorphous' state, although as-implanted GaP is not in the 'amorphous' state but in the

  2. A study on the resistance at bone-implant interface during implant insertion in a cadaver goat jaw model

    Directory of Open Access Journals (Sweden)

    Goutam Das

    2016-01-01

    Full Text Available Background: The aim of the study is to determine the resistance at bone-implant interface during insertion of dental implant. Materials and Methods: Freshly procured cadaver goat mandibles were collected from slaughterhouses. Four dental implants of two different diameters were inserted into osteotomized sites of the goat mandibles. The gradual changes in resonance frequency (RF were recorded in RF analyzer for the five consecutive turns of implant insertion. Results and Observations: RF was found to be positively correlated with diameter of dental implants. Conclusion: RF analysis can be used to determine the type of resistance the implant faces during insertion and the kind of bone density through which it passes. It gives a forecast of expected initial stability.

  3. Biomechanical implant treatment complications: a systematic review of clinical studies of implants with at least 1 year of functional loading.

    Science.gov (United States)

    Hsu, Yung-Ting; Fu, Jia-Hui; Al-Hezaimi, Khalid; Wang, Hom-Lay

    2012-01-01

    The aim of this article is to discuss the current literature available on the etiology and management of biomechanical complications of dental implant treatment. An electronic search of the PubMed database for English-language articles published before May 31, 2011, was performed based on a focus question: "How can biomechanical implant treatment complications be managed and identified?" The key words used were "dental implant," "etiology," "management," "excessive occlusal forces," "occlusal forces," "occlusion," "parafunctional habits," "biomechanical failure," "biomechanical complications," and "occlusal overloading." Clinical trials with a minimum of 10 implants followed for at least 1 year after functional loading were included. The initial electronic search identified 2,087 publications, most of which were eliminated, as they were animal studies, finite element analyses, bench-top studies, case reports, and literature reviews. After the titles, abstracts, and full text of 39 potentially eligible publications were reviewed, 15 studies were found to fulfill the inclusion criteria. Occlusal overloading was thought to be the primary etiologic factor in biomechanical implant treatment complications, which commonly included marginal bone loss, fracture of resin/ceramic veneers and porcelain, retention device or denture base fracture of implant-supported overdentures, loosening or fracture of abutment screws, and even implant failure. Occlusal overloading was positively associated with parafunctional habits such as bruxism. An appreciation of the intricacy of implant occlusion would allow clinicians to take a more preventive approach when performing implant treatment planning, as avoidance of implant overloading helps to ensure the long-term stability of implant-supported prostheses.

  4. Retrospective study investigating the clinical success of two provisional implant systems

    OpenAIRE

    Hotz, Nadine

    2011-01-01

    The use of dental implants allows a reliable stabilisation of prosthesis. Usually, definitive implants can´t be used for fixation of prosthesis during their healing period. Therefore, in many cases it is not possible to follow the demand of patients of an immediate loading of definitive implants to avoid a unfixed dental prosthesis. This is one domain of provisional dental implants. The present study of two provisional implant systems approves the benefit of provisional implants during...

  5. Number of implants for mandibular implant overdentures: a systematic review

    Science.gov (United States)

    Lee, Jeong-Yol; Kim, Ha-Young; Bryant, S. Ross

    2012-01-01

    PURPOSE The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants. PMID:23236572

  6. Implant-buccal plate distance as diagnostic parameter: a prospective cohort study on implant placement in fresh extraction sockets.

    Science.gov (United States)

    Capelli, Matteo; Testori, Tiziano; Galli, Fabio; Zuffetti, Francesco; Motroni, Alessandro; Weinstein, Roberto; Del Fabbro, Massimo

    2013-12-01

    The aim of this study is to investigate contour changes around immediate implants in fresh extraction sockets when different grafting procedures are performed, based on the distance between the external implant collar and the bony surface on the buccal plate (I-BP). A secondary aim is to assess the esthetic outcome via the implant esthetic score (IAS). This prospective cohort study was performed in three centers. Suitable patients to undergo implant placement in fresh extraction sockets were selected. Periodontal biotype, horizontal and vertical peri-implant bone defects, and dehiscences were assessed. Depending on I-BP, two types of grafting procedures were performed. In group A (I-BP sockets. No implant failed during the observation period. The mean follow-up was 25 months (range: 12 to 37 months). After 1 year of loading, group A showed a slight decrease in mean buccal volume, whereas group B had an increase in volume (P = 0.02). IAS was higher for group B than group A. When implants are placed immediately after tooth extraction, I-BP may represent a useful diagnostic parameter in choosing the most appropriate grafting procedure (IG versus IEG). In clinical cases in which the distance between implant surface and the buccal plate is <4 mm, the combination of internal and external grafting (IEG) is recommended to maintain the volume and the contour of the ridge and achieve a successful esthetic outcome.

  7. A new classification of peri-implant bone morphology: a radiographic study of patients with lower implant-supported mandibular overdentures

    NARCIS (Netherlands)

    Zhang, L.; Geraets, W.; Zhou, Y.; Wu, W.; Wismeijer, D.

    2014-01-01

    Objective This study aimed to classify peri-implant bone defects (PIBDs) on the basis of their radiographic appearance in a cohort of patients with lower implant-supported overdentures. Materials and methods Eighty-three patients with lower implant-supported overdentures were recruited to

  8. Electron microscopy of an Al-Cu of 1.3 at% obtained by implantation

    International Nuclear Information System (INIS)

    Cartraud, M.; Guillot, J.; Templier, C.; Louzolo, P.

    1985-01-01

    An Al-Cu alloy of 1.3 at% is obtained by implantation of Cu ions in thin foils of aluminium. The purpose of the electron-microscope study is to determine the ageing reactions of this alloy as compared with those occuring in the quenched solid solution. It has been shown that the implantation temperature is an essential parameter in the unmixing process. After a 77 K implantation 8 months of ageing at 20 0 C are necessary to obtain the first stages of unmixing characterized by the formation of Guinier-Prestion I zones, whereas after an implantation at room-temperature, the THETA'' phase is directly observed. The behaviour of the solid solution obtained at 77 K is similar to the conventional Al-Cu solid solution. On the contrary, during the implantation at room-temperature, the unmixing is already started and this fact can be explained on account of an enhanced diffusion. (orig./R)

  9. [Mechanical studies of lumbar interbody fusion implants].

    Science.gov (United States)

    Bader, R J; Steinhauser, E; Rechl, H; Mittelmeier, W; Bertagnoli, R; Gradinger, R

    2002-05-01

    In addition to autogenous or allogeneic bone grafts, fusion cages composed of metal or plastic are being used increasingly as spacers for interbody fusion of spinal segments. The goal of this study was the mechanical testing of carbon fiber reinforced plastic (CFRP) fusion cages used for anterior lumbar interbody fusion. With a special testing device according to American Society for Testing and Materials (ASTM) standards, the mechanical properties of the implants were determined under four different loading conditions. The implants (UNION cages, Medtronic Sofamor Danek) provide sufficient axial compression, shear, and torsional strength of the implant body. Ultimate axial compression load of the fins is less than the physiological compression loads at the lumbar spine. Therefore by means of an appropriate surgical technique parallel grooves have to be reamed into the endplates of the vertebral bodies according to the fin geometry. Thereby axial compression forces affect the implants body and the fins are protected from damaging loading. Using a supplementary anterior or posterior instrumentation, in vivo failure of the fins as a result of physiological shear and torsional spinal loads is unlikely. Due to specific complications related to autogenous or allogeneic bone grafts, fusion cages made of metal or carbon fiber reinforced plastic are an important alternative implant in interbody fusion.

  10. Implant stability and marginal bone level of microgrooved zirconia dental implants: A 3-month experimental study on dogs

    Directory of Open Access Journals (Sweden)

    Delgado-Ruíz Rafael Arcesio

    2014-01-01

    Full Text Available Background/Aim. The modification of implant surfaces could affect mechanical implant stability as well as dynamics and quality of peri-implant bone healing. The aim of this 3-month experimental study in dogs was to investigate implant stability, marginal bone levels and bone tissue response to zirconia dental implants with two laser-micro-grooved intraosseous surfaces in comparison with nongrooved sandblasted zirconia and sandblasted, high-temperature etched titanium implants. Methods. Implant surface characterization was performed using optical interferometric profilometry and energy dispersive X-ray spectroscopy. A total of 96 implants (4 mm in diameter and 10 mm in length were inserted randomly in both sides of the lower jaw of 12 Fox Hound dogs divided into groups of 24 each: the control (titanium, the group A (sandblasted zirconia, the group B (sandblasted zirconia plus microgrooved neck and the group C (sandblasted zirconia plus all microgrooved. All the implants were immediately loaded. Insertion torque, periotest values, radiographic crestal bone level and removal torque were recorded during the 3-month follow-up. Qualitative scanning electon micro-scope (SEM analysis of the bone-implant interfaces of each group was performed. Results. Insertion torque values were higher in the group C and control implants (p the control > the group B > the group A (p the control > the group B > the group A (p < 0.05. SEM showed that implant surfaces of the groups B and C had an extra bone growth inside the microgrooves that corresponded to the shape and direction of the microgrooves. Conclusion. The addition of micro-grooves to the entire intraosseous surface of zirconia dental implants enhances primary and secondary implant stability, promotes bone tissue ingrowth and preserves crestal bone levels.

  11. Influence of collar design on peri-implant tissue healing around immediate implants: A pilot study in Foxhound dogs.

    Science.gov (United States)

    Calvo-Guirado, José Luis; López-López, Patricia Jara; Maté Sánchez de Val, José Eduardo; Mareque-Bueno, Javier; Delgado-Ruiz, Rafael Arcesio; Romanos, Georgios E

    2015-07-01

    The study aims to assess the soft tissue level (STL) and crestal bone level (CBL), of titanium dental implants with different mixed collar abutments configurations. This study included 48 implants with the same dimensions. They were divided into two groups of 24 implants each one: implants with a polished collar of 2 mm plus a roughened area of 0.8 mm (CONTROL) and implants with a polished collar of 0.8 mm plus a micro-threated and roughened area of 2 mm (TEST). The implants were inserted randomly in the post-extraction sockets of P2, P3, P4, and M1 bilaterally in the lower jaw of six foxhound dogs. STL and CBL were evaluated after 8 and 12 weeks by histology and histometry. All implants were clinically and histologically osseointegrated. Healing patterns examined microscopically at 8 and 12 weeks for both groups yielded similar qualitative findings for the STL evaluation, without significant differences between groups (P > 0.05). CBL was significantly higher in the buccal side in comparison with the lingual side for both groups (P implant shoulder to the top of the bony crest) and IS-C (distance from the implant shoulder to the first bone-to-implant contact) values significantly higher for control group in comparison with test (P < 0.05). At 12 weeks, CBL showed increased values for both groups that were higher in controls group in comparison with test (P < 0.05). Bony crest resorption could not be avoided both at test and control sites. However, the neck conformation at the test sites reduced the buccal bone resorption. Soft tissue dimensions were similar both at the test and control sites. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Influence of occlusal loading on peri-implant clinical parameters. A pilot study.

    Science.gov (United States)

    Pellicer-Chover, Hilario; Viña-Almunia, José; Romero-Millán, Javier; Peñarrocha-Oltra, David; García-Mira, Berta; Peñarrocha-Diago, María

    2014-05-01

    To investigate the relation between occlusal loading and peri-implant clinical parameters (probing depth, bleeding on probing, gingival retraction, width of keratinized mucosa, and crevicular fluid volume) in patients with implant-supported complete fixed prostheses in both arches. This clinical study took place at the University of Valencia (Spain) dental clinic. It included patients attending the clinic for regular check-ups during at least 12 months after rehabilitation of both arches with implant-supported complete fixed ceramo-metallic prostheses. One study implant and one control implant were established for each patient using the T-Scan®III computerized system (Tesco, South Boston, USA). The maxillary implant closest to the point of maximum occlusal loading was taken as the study implant and the farthest (with least loading) as the control. Occlusal forces were registered with the T-Scan® III and then occlusal adjustment was performed to distribute occlusal forces correctly. Peri-implant clinical parameters were analyzed in both implants before and two and twelve months after occlusal adjustment. Before occlusal adjustment, study group implants presented a higher mean volume of crevicular fluid (51.3 ± 7.4 UP) than the control group (25.8 ± 5.5 UP), with statistically significant difference. Two months after occlusal adjustment, there were no significant differences between groups (24.6 ± 3.8 UP and 26 ± 4.5 UP respectively) (p=0.977). After twelve months, no significant differences were found between groups (24.4 ± 11.1 UP and 22.5 ± 8.9 UP respectively) (p=0.323). For the other clinical parameters, no significant differences were identified between study and control implants at any of the study times (p>0.05). Study group implants receiving higher occlusal loading presented significantly higher volumes of crevicular fluid than control implants. Crevicular fluid volumes were similar in both groups two and twelve months after occlusal adjustment.

  13. Vacancy supersaturations produced by high-energy ion implantation

    International Nuclear Information System (INIS)

    Venezia, V.C.; Eaglesham, D.J.; Jacobson, D.C.; Gossmann, H.J.

    1998-01-01

    A new technique for detecting the vacancy clusters produced by high-energy ion implantation into silicon is proposed and tested. This technique takes advantage of the fact that metal impurities, such as Au, are gettered near one-half of the projected range (1/2 R p ) of MeV implants. The vacancy clustered region produced by a 2 MeV Si + implant into silicon has been labeled with Au diffused in from the front surface. The trapped Au was detected by Rutherford backscattering spectrometry (RBS) to profile the vacancy clusters. Cross section transmission electron microscopy (XTEM) analysis shows that the Au in the region of vacancy clusters is in the form of precipitates. By annealing MeV implanted samples prior to introduction of the Au, changes in the defect concentration within the vacancy clustered region were monitored as a function of annealing conditions

  14. The effect of implant macro-thread design on implant stability in the early post-operative period: a randomized, controlled pilot study.

    Science.gov (United States)

    McCullough, Jeffrey J; Klokkevold, Perry R

    2017-10-01

    Available literature suggests there is a transient drop in implant stability from approximately week 0 to week 3-4 as a result of peri-implant bone remodeling as it transitions from a primary, mechanical stability to a secondary, biological stability. Research investigating the influence of macro-thread design on this process is scant. The specific aim of this study was to evaluate the role of macro-thread design on implant stability in the early post-operative healing period using resonance frequency analysis (RFA). Seven patients, each missing at least two posterior teeth in the same arch, were included in the study. Three patients qualified for four implants resulting in a total of 10 matched pairs. All sites were healed (>6 months), non-grafted sites with sufficient bone to place implants. Each site in a matched pair was randomly assigned to receive either a control (Megagen EZ Plus Internal; EZ) or test (Megagen AnyRidge; AR) implant. The test implant incorporates a novel thread design with a wide thread depth and increased thread pitch. RFA was used to determine implant stability quotient (ISQ) values for each implant at the time of placement and weekly for the first 8 weeks. Implants consistently achieved a relatively high insertion torque (30-45 N/cm) and high initial ISQ value (79.8 ± 1.49). Baseline ISQ values for test (AR; 79.55 ± 1.61) and control (EZ; 80.05 ± 1.37) implants were similar. A general pattern of stability from baseline through all eight follow-up evaluations was observed for the test implants. A pattern of decreasing ISQ values was observed for the control implants across the early follow-up evaluations up to week four, where the value plateaued. There was a statistically significant main effect due to implant type (P implant type and time (P implants performed differently at certain time points. Within the limitations of this study, macro-thread design appears to play a role in implant stability in the early post

  15. The effect of MEVVA ion implantation on the tribological properties of PVD-TiN films

    International Nuclear Information System (INIS)

    Manory, R.; Mollica, S.

    1998-01-01

    The present work is the first study in which the effects of metal evaporation vacuum (MEVVA) implantation are studied on TiN of the PVD type which is commercially available in Australia. The MEVVA ion implanter differs from the 'conventional' type of ion implanter in the fact that it has a high throughput of metal ions which are not mass analysed and therefore has more potential for industrial non-electronic applications. TiN-coated steel samples have been implanted with two types of species - one light and one heavy - C + and W + respectively. The samples were analysed by Rutherford backscattering (RBS) and x-ray diffraction (XRD). The tribological performance was assessed by pin-on-disc and microhardness. The results show that carbon implantation was very effective in improving the friction coefficient by the formation of a carbonaceous layer on the surface. XRD also shows formation of TiC in the near surface region. W implantation does not improve the friction coefficient but improves the lifetime of the coating. Unimplanted films fail in the pin-on-disk test after 7000 cycles, whereas implanted films are still well adhered after 18000 cycles

  16. Effect of implant macro-design on primary stability: A prospective clinical study.

    Science.gov (United States)

    Lozano-Carrascal, Naroa; Salomó-Coll, Oscar; Gilabert-Cerdà, Marta; Farré-Pagés, Nuria; Gargallo-Albiol, Jordi; Hernández-Alfaro, Federico

    2016-03-01

    Implant restorations have become a high predictable treatment option. Several caracteristics such as surgical technique and implant design can influence the treatment outcomes. The aim of the present study was to evaluate the influence of implant macro-design on primary stability measured with resonance frequency analysis (RFA) and insertion torque (IT). Material and Mehods: A total of 47 implants divided in two groups: Test group (TI): 22 Tapered MIS® Seven implants; Control group (CI): 25 cylindrical Astra® Osseospeed implants. All implants were inserted following the manufacturers' standard protocols. Implant primary stability was measured at the moment of implant placement by registering insertion torque values (ITv) and ISQ values by means of Osstell™ Mentor (ISQv) (Integration Diagnostic Ltd., Goteborg, Sweden). In the mandible, mean ISQv for tapered implants (TI) was 71.67±5.16 and for cylindrical implants (CI) 57.15±4.83 (p=0.01). Mean insertion torque was 46.67±6.85 Ncm for TI and 35.77±6.72 Ncm for CI (p=0.01). In the maxilla, mean ISQ was 67.2±4.42 for tapered implants and 49.17±15.30 for cylindrical implants (p=0.01). Mean insertion torque for TI was 41.5±6.26 Ncm and for CI 39.17±6.34 Ncm (p>0.05). For tapered implants, no correlation could be found between implant diameter and primary stability. But for cylindrical implants there was a statistically significant correlation between implant diameter and primary stability: ITv (p=0.03); ISQv (p=0.04). Within the limits of the present study, tapered shaped implants achieve higher primary stability measured through ISQ and insertion torque values. Moreover, for cylindrical implants positive correlation has been established between implant diameter and primary stability.

  17. A prospective study evaluating cochlear implant management skills: development and validation of the Cochlear Implant Management Skills survey.

    Science.gov (United States)

    Bennett, R J; Jayakody, D M P; Eikelboom, R H; Taljaard, D S; Atlas, M D

    2016-02-01

    To investigate the ability of cochlear implant (CI) recipients to physically handle and care for their hearing implant device(s) and to identify factors that may influence skills. To assess device management skills, a clinical survey was developed and validated on a clinical cohort of CI recipients. Survey development and validation. A prospective convenience cohort design study. Specialist hearing implant clinic. Forty-nine post-lingually deafened, adult CI recipients, at least 12 months postoperative. Survey test-retest reliability, interobserver reliability and responsiveness. Correlations between management skills and participant demographic, audiometric, clinical outcomes and device factors. The Cochlear Implant Management Skills survey was developed, demonstrating high test-retest reliability (0.878), interobserver reliability (0.972) and responsiveness to intervention (skills training) [t(20) = -3.913, P = 0.001]. Cochlear Implant Management Skills survey scores range from 54.69% to 100% (mean: 83.45%, sd: 12.47). No associations were found between handling skills and participant factors. This is the first study to demonstrate a range in cochlear implant device handling skills in CI recipients and offers clinicians and researchers a tool to systematically and objectively identify shortcomings in CI recipients' device handling skills. © 2015 John Wiley & Sons Ltd.

  18. Spatial memory in nonhuman primates implanted with the subdural pharmacotherapy device.

    Science.gov (United States)

    Ludvig, Nandor; Tang, Hai M; Baptiste, Shirn L; Stefanov, Dimitre G; Kral, John G

    2015-06-01

    This study investigated the possible influence of the Subdural Pharmacotherapy Device (SPD) on spatial memory in 3 adult, male bonnet macaques (Macaca radiata). The device was implanted in and above the subdural/subarachnoid space and cranium overlaying the right parietal/frontal cortex: a circuitry involved in spatial memory processing. A large test chamber, equipped with four baited and four non-baited food-ports at different locations, was used: reaches into empty food ports were counted as spatial memory errors. In this study of within-subject design, before SPD implantation (control) the animals made mean 373.3 ± 114.9 (mean ± SEM) errors in the first spatial memory test session. This value dropped to 47.7 ± 18.4 by the 8th session. After SPD implantation and alternating cycles of transmeningeal saline delivery and local cerebrospinal fluid (CSF) drainage in the implanted cortex the spatial memory error count, with the same port locations, was 33.0 ± 12.2 during the first spatial memory test session, further decreasing to 5.7 ± 3.5 by the 8th post-implantation session (Pmemory performance, which in fact included at least one completely error-free session per animal over time. The study showed that complication-free implantation and use of the SPD over the parietal and frontal cortices for months leave spatial memory processes intact in nonhuman primates. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Outcomes of cochlear implantation in deaf children of deaf parents: comparative study.

    Science.gov (United States)

    Hassanzadeh, S

    2012-10-01

    This retrospective study compared the cochlear implantation outcomes of first- and second-generation deaf children. The study group consisted of seven deaf, cochlear-implanted children with deaf parents. An equal number of deaf children with normal-hearing parents were selected by matched sampling as a reference group. Participants were matched based on onset and severity of deafness, duration of deafness, age at cochlear implantation, duration of cochlear implantation, gender, and cochlear implant model. We used the Persian Auditory Perception Test for the Hearing Impaired, the Speech Intelligibility Rating scale, and the Sentence Imitation Test, in order to measure participants' speech perception, speech production and language development, respectively. Both groups of children showed auditory and speech development. However, the second-generation deaf children (i.e. deaf children of deaf parents) exceeded the cochlear implantation performance of the deaf children with hearing parents. This study confirms that second-generation deaf children exceed deaf children of hearing parents in terms of cochlear implantation performance. Encouraging deaf children to communicate in sign language from a very early age, before cochlear implantation, appears to improve their ability to learn spoken language after cochlear implantation.

  20. Study of hydrogen implanted in aluminium

    International Nuclear Information System (INIS)

    Bugeat, J.P.; Chami, A.C.; Danielou, R.; Ligeon, E.

    1976-01-01

    An aluminium sample was implanted with deuterium and hydrogen at 5keV and 10keV respectively. The 1 H( 11 B,α) 8 Be* and D( 3 He,p) 4 He reactions were used for the analysis of H and D respectively. The implanted deuterium was shown to be as a whole in a tetrahedral site as far as the implantation temperature is lower than 175K, beyond that temperature the deuterium is randomly located. When the implantation temperature increases from 33K up to 275K the tetrahedral siting remains during annealing. The migration temperatures of hydrogen (or temperature of transition from the tetrahedral siting to a random distribution) experimentally observed during annealing (300K) and for increased implantation temperatures, show that the tetrahedral site is associated with a monovacancy migrating at 300K, the diffusion temperature of hydrogen being lower than 180K [fr

  1. The diagnosis of breast implant rupture: MRI findings compared with findings at explantation

    International Nuclear Information System (INIS)

    Hoelmich, Lisbet R.; Vejborg, Ilse; Conrad, Carsten; Sletting, Susanne; McLaughlin, Joseph K.

    2005-01-01

    Study objective: The aim of this study was to evaluate the accuracy of Magnetic Resonance Imaging (MRI) as performed according to a strict study protocol in diagnosing rupture of silicone breast implants. Material and methods: The study population consisted of 64 women with 118 implants, who had participated in either one or two study MRI examinations, aiming at determining the prevalence and incidence of silent implant rupture, respectively, and who subsequently underwent explantation. Implant rupture status was determined by four independent readers and a consensus diagnosis of either rupture (intracapsular or extracapsular), possible rupture or intact implant was then obtained. Strict predetermined rupture criteria were applied as described in this report and findings at surgery were abstracted in a standardised manner and results compared. Results: At MRI, 66 implants were diagnosed as ruptured, nine as possibly ruptured and 43 as intact. Among the ruptured implants, 27 were categorized as extracapsular. At surgery, on average 297 days after the MRI, 65 of the 66 rupture diagnoses were confirmed, as were 20 of the cases with extracapsular silicone. Eight of the nine possibly ruptured implants were in fact ruptured at surgery. Thirty-four of the 43 intact implants were described as intact at surgery. When categorising possible ruptures as ruptures, there were one false positive and nine false negative rupture diagnoses at MRI yielding an accuracy of 92%, a sensitivity of 89%, and a specificity of 97%. Correspondingly, the predictive value of a positive MRI examination was 99% and the predictive value of a negative MRI examination was 79%. Conclusions: We conclude that MRI is highly accurate for identification of silicone breast implant rupture, with a high sensitivity and specificity when evaluation of images are based on presence of well-defined rupture criteria

  2. Influence of source batch Sk dispersion on dosimetry for prostate cancer treatment with permanent implants

    DEFF Research Database (Denmark)

    Nunez-Cumplido, Eduardo; Perez-Calatayud, J; Casares-Magaz, O

    2015-01-01

    PURPOSE: In clinical practice, specific air kerma strength (SK) value is used in treatment planning system (TPS) permanent brachytherapy implant calculations with (125)I and (103)Pd sources; in fact, commercial TPS provide only one SK input value for all implanted sources and the certified shipment...

  3. Los implantes MG-OSSEOUS: Estudio multicéntrico retrospectivo MG-OSSEOUS implants: A multicentric retrospective study

    Directory of Open Access Journals (Sweden)

    E. Serrano Caturla

    2006-12-01

    commercial implants. Material and methodology. This is a retrospective multicentric study coordinated by a company called Scientific Management in O&SS (Barcelona, Spain. 1001 dental implants were placed in 247 patients and 328 prostheses were designed between 2004 and 2005, with a follow-up of two years. All implants were loaded with prostheses. We detail and analyze each implant, according to the diameter, length, position, surgical timing, loadings, design and types of prostheses and complementary surgical procedures, either synchronic or metachronic. Results. After the statistical method was homogenized, we were able to report an overall implant survival rate of 97.8% with monitoring of two years. The failures depending on the peculiarities of each clinical case are provided. No prosthetic failures are reported. Discussion. The criteria and indications applied by the professionals to the MG-OSSEOUS implants are standardized depending on the clinical case. Our results are compared with the international scientific literature, past and present, with these procedures totally agreeing with those found in the history of implantology. Finally, our survey is compared with those published by the Branemark team. Conclusion. The mixture between the quality of the MGOSSEOUS implants and the scientifically supported criteria regarding the implants, reveals an implant failure of 2.2% over two years, with a survival of 100% of both the replaced implants and the loaded prostheses.

  4. Vertical Root Fracture: Preservation of the Alveolar Ridge Using Immediate Implants

    Directory of Open Access Journals (Sweden)

    Edmar de Oliveira Oya

    2014-01-01

    Full Text Available Teeth with vertical root fracture (VRF have complete or incomplete fractures that begin in the root and extend toward the occlusal surface. The most frequent causes of VRF originate from physical trauma, occlusal prematurity, inadequate endodontic treatment, and iatrogenic causes. Diagnose is difficult and delay can cause stomatognathic system problem. The purpose of this case report was to evaluate immediate implant placement after extraction of teeth with vertical root fracture. For the 1st case, the VRF in 1st left lower molar was confirmed during surgical flap and at the same time, the tooth was removed and immediate implant was placed. For the 2nd case, the VRF 1st left lower molar was confirmed during endodontic access and at the same appointment, the tooth was removed and the immediate implant is placed. Several studies have shown that immediate implants have similar success rates when compared with late implants. Consider that this approach is a safe procedure with favorable prognosis. In cases of VRF, the main factor to be considered is the presence of adequate bone support and immediate implants can preserve the vertical bone height, adding the fact that good patient compliance reduces the number of surgical interventions and promotes the functionality of stomatognathic system.

  5. A study on setting of the fatigue limit of temporary dental implants.

    Science.gov (United States)

    Kim, M H; Cho, E J; Lee, J W; Kim, E K; Yoo, S H; Park, C W

    2017-07-01

    A temporary dental implant is a medical device which is temporarily used to support a prosthesis such as an artificial tooth used for restoring patient's masticatory function during implant treatment. It is implanted in the oral cavity to substitute for the role of tooth. Due to the aging and westernization of current Korean society, the number of tooth extraction and implantation procedures is increasing, leading to an increase in the use and development of temporary dental implants. Because an implant performs a masticatory function in place of a tooth, a dynamic load is repeatedly put on the implant. Thus, the fatigue of implants is reported to be the most common causes of the fracture thereof. According to the investigation and analysis of the current domestic and international standards, the standard for fatigue of implant fixtures is not separately specified. Although a test method for measuring the fatigue is suggested in an ISO standard, it is a standard for permanent dental implants. Most of the test standards for Korean manufacturers and importers apply 250 N or more based on the guidance for the safety and performance evaluation of dental implants. Therefore, this study is intended to figure out the fatigue standard which can be applied to temporary dental implants when measuring the fatigue according to the test method suggested in the permanent dental implant standard. The results determined that suitable fatigue standards of temporary dental implants should be provided by each manufacturer rather than applying 250 N. This study will be useful for the establishment of the fatigue standards and fatigue test methods of the manufacturers and importers of temporary dental implants.

  6. EEG frontal asymmetry related to pleasantness of music perception in healthy children and cochlear implanted users.

    Science.gov (United States)

    Vecchiato, G; Maglione, A G; Scorpecci, A; Malerba, P; Marsella, P; Di Francesco, G; Vitiello, S; Colosimo, A; Babiloni, Fabio

    2012-01-01

    Interestingly, the international debate about the quality of music fruition for cochlear implanted users does not take into account the hypothesis that bilateral users could perceive music in a more pleasant way with respect to monolateral users. In this scenario, the aim of the present study was to investigate if cerebral signs of pleasantness during music perception in healthy child are similar to those observed in monolateral and in bilateral cochlear implanted users. In fact, previous observations in literature on healthy subjects have indicated that variations of the frontal EEG alpha activity are correlated with the perceived pleasantness of the sensory stimulation received (approach-withdrawal theory). In particular, here we described differences between cortical activities estimated in the alpha frequency band for a healthy child and in patients having a monolateral or a bilateral cochlear implant during the fruition of a musical cartoon. The results of the present analysis showed that the alpha EEG asymmetry patterns observed in a healthy child and that of a bilateral cochlear implanted patient are congruent with the approach-withdrawal theory. Conversely, the scalp topographic distribution of EEG power spectra in the alpha band resulting from the monolateral cochlear user presents a different EEG pattern from the normal and bilateral implanted patients. Such differences could be explained at the light of the approach-withdrawal theory. In fact, the present findings support the hypothesis that a monolateral cochlear implanted user could perceive the music in a less pleasant way when compared to a healthy subject or to a bilateral cochlear user.

  7. Evaluation of bone loss in antibacterial coated dental implants: An experimental study in dogs

    International Nuclear Information System (INIS)

    Godoy-Gallardo, Maria; Manzanares-Céspedes, Maria Cristina; Sevilla, Pablo; Nart, José; Manzanares, Norberto; Manero, José M.; Gil, Francisco Javier; Boyd, Steven K.; Rodríguez, Daniel

    2016-01-01

    The aim of this study was to evaluate the in vivo effect of antibacterial modified dental implants in the first stages of peri-implantitis. Thirty dental implants were inserted in the mandibular premolar sites of 5 beagle dogs. Sites were randomly assigned to Ti (untreated implants, 10 units), Ti-Ag (silver electrodeposition treatment, 10 units), and Ti-TSP (silanization treatment, 10 units). Coated implants were characterized by scanning electron microscopy, interferometry and X-ray photoelectron spectroscopy. Two months after implant insertion, experimental peri-implantitis was initiated by ligature placement. Ligatures were removed 2 months later, and plaque formation was allowed for 2 additional months. Clinical and radiographic analyses were performed during the study. Implant-tissue samples were prepared for micro computed tomography, backscattered scanning electron microscopy, histomorphometric and histological analyses and ion release measurements. X-ray, SEM and histology images showed that vertical bone resorption in treated implants was lower than in the control group (P < 0.05). This effect is likely due to the capacity of the treatments to reduce bacteria colonization on the implant surface. Histological analysis suggested an increase of peri-implant bone formation on silanized implants. However, the short post-ligature period was not enough to detect differences in clinical parameters among implant groups. Within the limits of this study, antibacterial surface treatments have a positive effect against bone resorption induced by peri-implantitis. - Highlights: • Dental implants were modified with two antibacterial treatments, silver and TESPSA silanization. • Performance of the modified dental implants was studied in vivo. • Treated implants showed less peri-implant bone resorption. • Decrease in bone resorption was attributed to the antibacterial surface treatments. • Silane treatment enhanced bone regeneration around dental implants.

  8. Evaluation of bone loss in antibacterial coated dental implants: An experimental study in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Godoy-Gallardo, Maria [Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby (Denmark); Manzanares-Céspedes, Maria Cristina [Unidad de Anatomía y Embriología Humana, Faculty of Dentistry, University of Barcelona, Barcelona (Spain); Sevilla, Pablo [Department of Mechanics, Escola Universitària Salesiana de Sarrià (EUSS), Barcelona (Spain); Nart, José [Department of Periodontology, School of Dentistry, Universitat Internacional de Catalunya, Sant Cugat (Spain); Manzanares, Norberto [Unidad de Anatomía y Embriología Humana, Faculty of Dentistry, University of Barcelona, Barcelona (Spain); Manero, José M. [Biomaterials, Biomechanics and Tissue Engineering Group, Dept. Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC-BarcelonaTECH), Barcelona (Spain); Centre for Research in NanoEngineering (CRNE), UPC-BarcelonaTECH, Barcelona (Spain); Gil, Francisco Javier [Universitat Internacional de Catalunya, Sant Cugat (Spain); Boyd, Steven K. [McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Alberta (Canada); Rodríguez, Daniel, E-mail: daniel.rodriguez.rius@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Dept. Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC-BarcelonaTECH), Barcelona (Spain); Centre for Research in NanoEngineering (CRNE), UPC-BarcelonaTECH, Barcelona (Spain)

    2016-12-01

    The aim of this study was to evaluate the in vivo effect of antibacterial modified dental implants in the first stages of peri-implantitis. Thirty dental implants were inserted in the mandibular premolar sites of 5 beagle dogs. Sites were randomly assigned to Ti (untreated implants, 10 units), Ti-Ag (silver electrodeposition treatment, 10 units), and Ti-TSP (silanization treatment, 10 units). Coated implants were characterized by scanning electron microscopy, interferometry and X-ray photoelectron spectroscopy. Two months after implant insertion, experimental peri-implantitis was initiated by ligature placement. Ligatures were removed 2 months later, and plaque formation was allowed for 2 additional months. Clinical and radiographic analyses were performed during the study. Implant-tissue samples were prepared for micro computed tomography, backscattered scanning electron microscopy, histomorphometric and histological analyses and ion release measurements. X-ray, SEM and histology images showed that vertical bone resorption in treated implants was lower than in the control group (P < 0.05). This effect is likely due to the capacity of the treatments to reduce bacteria colonization on the implant surface. Histological analysis suggested an increase of peri-implant bone formation on silanized implants. However, the short post-ligature period was not enough to detect differences in clinical parameters among implant groups. Within the limits of this study, antibacterial surface treatments have a positive effect against bone resorption induced by peri-implantitis. - Highlights: • Dental implants were modified with two antibacterial treatments, silver and TESPSA silanization. • Performance of the modified dental implants was studied in vivo. • Treated implants showed less peri-implant bone resorption. • Decrease in bone resorption was attributed to the antibacterial surface treatments. • Silane treatment enhanced bone regeneration around dental implants.

  9. Patients' experiences of dental implant treatment: A literature review of key qualitative studies.

    Science.gov (United States)

    Kashbour, W A; Rousseau, N S; Ellis, J S; Thomason, J M

    2015-07-01

    To identify and summarise the findings of previous qualitative studies relating to patients' experience of dental implant treatment (DIT) at various stages of their implant treatment, by means of textual narrative synthesis. Original articles reporting patients' experience with dental implant were included. A two-stage search of the literature, electronic and hand search identified relevant qualitative studies up to July 2014. An extensive electronic search was conducted of databases including PubMed, Embase, Scopus, Web of Knowledge, Cochrane Database and Google Scholar. Included primary studies (n=10) used qualitative research methods and qualitative analysis to investigate patients' experiences with dental implants treatment. While the growing interest in implant treatment for the replacement of missing dentition is evident, it is essential to investigate patients' perceptions of different aspects of implant treatment. This textual narrative synthesis conducted to review qualitative studies which provided insight into patients' experience of two types of implant prostheses namely ISOD (implant-supported overdenture) and FISP (fixed implant supported prostheses). Primary reviewed studies tended to include samples of older patients with more extensive tooth loss, and to focus on experiences prior to and post-treatment rather than on the treatment period itself. Findings across reviewed studies (n=10) suggested that patients with FISP thought of implant treatment as a process of 'normalisation'(1) and believed that such implant restorations could be similar to natural teeth, whereas patients with ISOD focused more on the functional and social advantages of their implant treatment. The growing interest in qualitative research is evident in several branches of clinical dentistry and dental implantology is not an exception. Qualitative studies concerning the patients account of their experience of dental implants is however limited. The aim of this review is to

  10. Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

    DEFF Research Database (Denmark)

    Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

    2017-01-01

    OBJECTIVES: The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase and Cochrane library search...... of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment...... loss around implants with a scalloped implant-abutment connection. CONCLUSIONS: A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must...

  11. Analysis of the causes of dental implant fracture: A retrospective clinical study.

    Science.gov (United States)

    Stoichkov, Biser; Kirov, Dimitar

    2018-01-01

    Fracture of osseointegrated dental implants is the most severe mechanical complication. The aim of the present study was to analyze possible causative factors for implant body fracture. One hundred and one patients with 218 fitted implants and a follow-up period of 3 to 10 years were studied. Factors associated with biomechanical and physiologic overloading such as parafunctional activity (eg, bruxism), occlusion, and cantilevers, and factors related to the planning of the dental prosthesis, available bone volume, implant area, implant diameter, number of implants, and their inclination were tracked. The impact of their effect was analyzed using the Bonferroni-corrected post-hoc Mann-Whitney test for each group. The incidence of dental implant fracture was 2.3% in the investigated cases. Improper treatment planning, bruxism, and time of the complication setting in were the main factors leading to this complication. Typical size effect was established only for available bruxism, occlusal errors, and their activity duration. These complications were observed most often with single crown prostheses, and in combination with parafunctional activities such as bruxism and lack of implant-protected occlusion. Occlusal overload due to bruxism or inappropriate or inadequate occlusion as a single factor or a combination of these factors during the first years after the functional load can cause implant fracture. Fracture of the implant body more frequently occurred with single crowns than with other implant-supported fixed dental prostheses.

  12. Superficial or deep implantation of motor nerve after denervation: an experimental study--superficial or deep implantation of motor nerve.

    Science.gov (United States)

    Askar, Ibrahím; Sabuncuoglu, Bízden Tavíl

    2002-01-01

    Neurorraphy, conventional nerve grafting technique, and artificial nerve conduits are not enough for repair in severe injuries of peripheral nerves, especially when there is separation of motor nerve from muscle tissue. In these nerve injuries, reinnervation is indicated for neurotization. The distal end of a peripheral nerve is divided into fascicles and implanted into the aneural zone of target muscle tissue. It is not known how deeply fascicles should be implanted into muscle tissue. A comparative study of superficial and deep implantation of separated motor nerve into muscle tissue is presented in the gastrocnemius muscle of rabbits. In this experimental study, 30 white New Zealand rabbits were used and divided into 3 groups of 10 rabbits each. In the first group (controls, group I), only surgical exposure of the gastrocnemius muscle and motor nerve (tibial nerve) was done without any injury to nerves. In the superficial implantation group (group II), tibial nerves were separated and divided into their own fascicles. These fascicles were implanted superficially into the lateral head of gastrocnemius muscle-aneural zone. In the deep implantation group (group III), the tibial nerves were separated and divided into their own fascicles. These fascicles were implanted around the center of the muscle mass, into the lateral head of the gastrocnemius muscle-aneural zone. Six months later, histopathological changes and functional recovery of the gastrocnemius muscle were investigated. Both experimental groups had less muscular weight than in the control group. It was found that functional recovery was achieved in both experimental groups, and was better in the superficial implantation group than the deep implantation group. EMG recordings revealed that polyphasic and late potentials were frequently seen in both experimental groups. Degeneration and regeneration of myofibrils were observed in both experimental groups. New motor end-plates were formed in a scattered

  13. Short Implants: New Horizon in Implant Dentistry.

    Science.gov (United States)

    Jain, Neha; Gulati, Manisha; Garg, Meenu; Pathak, Chetan

    2016-09-01

    The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration.

  14. Effect of implant macro-design on primary stability: A prospective clinical study

    OpenAIRE

    Lozano-Carrascal, Naroa; Salom?-Coll, Oscar; Gilabert-Cerd?, Marta; Farr?-Pag?s, Nuria; Gargallo-Albiol, Jordi; Hern?ndez-Alfaro, Federico

    2016-01-01

    Background Implant restorations have become a high predictable treatment option. Several caracteristics such as surgical technique and implant design can influence the treatment outcomes. The aim of the present study was to evaluate the influence of implant macro-design on primary stability measured with resonance frequency analysis (RFA) and insertion torque (IT). Material and Methods A total of 47 implants divided in two groups: Test group (TI): 22 Tapered MIS? Seven implants; Control group...

  15. Influence of Palatal Coverage and Implant Distribution on Implant Strain in Maxillary Implant Overdentures.

    Science.gov (United States)

    Takahashi, Toshihito; Gonda, Tomoya; Mizuno, Yoko; Fujinami, Yozo; Maeda, Yoshinobu

    2016-01-01

    Maxillary implant overdentures are often used in clinical practice. However, there is no agreement or established guidelines regarding prosthetic design or optimal implant placement configuration. The purpose of this study was to examine the influence of palatal coverage and implant number and distribution in relation to impact strain under maxillary implant overdentures. A maxillary edentulous model with implants and experimental overdentures with and without palatal coverage was fabricated. Four strain gauges were attached to each implant, and they were positioned in the anterior, premolar, and molar areas. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the implant strains were compared using one-way analysis of variance (P = .05). The palatolabial strain was much higher on anterior implants than on other implants in both denture types. Although there was no significant difference between the strain under dentures with and without palatal coverage, palateless dentures tended to result in higher implant strain than dentures with palatal coverage. Dentures supported by only two implants registered higher strain than those supported by four or six implants. Implants under palateless dentures registered higher strain than those under dentures with palatal coverage. Anterior implants exhibited higher palatolabial strain than other implants regardless of palatal coverage and implant configuration; it is therefore recommended that maxillary implant overdentures should be supported by six implants with support extending to the distal end of the arch.

  16. Comparative Study of Bio-implantable Acoustic Generator Architectures

    International Nuclear Information System (INIS)

    Christensen, D; Roundy, S

    2013-01-01

    This paper is a comparative study of the design spaces of two bio-implantable acoustically excited generator architectures: the thickness-stretch-mode circular piezoelectric plate and the bending-mode unimorph piezoelectric diaphragm. The generators are part of an acoustic power transfer system for implanted sensors and medical devices such as glucose monitors, metabolic monitors, drug delivery systems, etc. Our studies indicate that at small sizes the diaphragm architecture outperforms the plate architecture. This paper will present the results of simulation studies and initial experiments that explore the characteristics of the two architectures and compare their performance

  17. Microscopic Study of Surface Microtopographic Characteristics of Dental Implants

    Science.gov (United States)

    Sezin, M.; Croharé, L.; Ibañez, J.C.

    2016-01-01

    Objective: To determine and compare the micro topographic characteristics of dental implants submitted to different surface treatments, using scanning electron microscopy (SEM). Materials and Methods: Implants were divided into 7 groups of 3 specimens each, according to the surface treatment used: group 1: Osseotite, BIOMET 3i; group 2: SLA surface, Institut Straumann AG; group 3: Oxalife surface, Tree-Oss implant; group 4: B&W implant surface; group 5: Q-implant surface; group 6: ML implant surface; group 7: RBM surface, Rosterdent implant. The surfaces were examined under SEM (Carl Zeiss FE-SEM-SIGMA). Image Proplus software was used to determine the number and mean diameter of pores per area unit (mm). The data obtained were analyzed with the Mann-Whitney test. A confocal laser microscope (LEXT-OLS4100 Olympus) was used to conduct the comparative study of surface roughness (Ra). Data were analyzed using Tukey's HSD test. Results: The largest average pore diameter calculated in microns was found in group 5 (3.45 µm+/-1.91) while the smallest in group 7 (1.47µm+/-1.29). Significant differences were observed among each one of the groups studied (p<0.05). The largest number of pores/mm2 was found in group 2 (229343) and the smallest number in group 4 (10937). Group 2 showed significant differences regarding the other groups (p<0.05). The greatest roughness (Ra) was observed in group 2 (0.975µm+/-0.115) and the smallest in group 4 (0.304µm+/-0.063). Group 2 was significantly different from the other groups (p<0.05). Conclusion: The micro topography observed in the different groups presented dissimilar and specific features, depending on the chemical treatment used for the surfaces.. PMID:27335615

  18. The Austrian breast implant register: recent trends in implant-based breast surgery.

    Science.gov (United States)

    Wurzer, Paul; Rappl, Thomas; Friedl, Herwig; Kamolz, Lars-Peter; Spendel, Stephan; Hoflehner, Helmut; Parvizi, Daryousch

    2014-12-01

    Due to the fact that the number of breast implant surgeries for cosmetic and medical purposes is rising yearly, a discussion about the quality of service for both patients and physicians is more important than ever. To this end, we reviewed the Austrian Breast Implant Register with one specific question in mind: What are the trends? In the statistical analysis of the Austrian Breast Implant Register, we were able to identify 13,112 registered breast implants between 2004 and 2012. The whole dataset was then divided into medical and cosmetic groups. We focused on device size, surface characteristics, filling material, device placement and incision site. All factors were considered for all examined years. In summary, the most used device had a textured surface (97 %) and silicone gel as the filling material (93 %). The mean size of implants for the cosmetic group was 240 cc, placement was submuscular (58 %) and the incision site was inframammary (67 %). In the medical group, the mean size was 250 cc. Yearly registrations had their peak in 2008 (1,898 registered devices); from this year on, registrations decreased annually. A slight trend away from subglandular placement in the cosmetic group was noted. Also, the usage of implants with polyurethane surface characteristics has increased since 2008. The smooth surface implants had a peak usage in 2006 and their usage decreased steadily from then on whereas the textured surface was steady over the years. Keeping the problems related to the quality of breast implants in mind, we could recommend an obligatory national register. Organisations of surgeons and governments should develop and establish these registers. Furthermore, an all-encompassing international register should be established by the European Union and the American FDA (Food and Drug Administration); this might be useful in comparing the individual country registers and also would help in delivering "evidence based" medicine in cosmetic and medical procedures

  19. The influence of micro and macro-geometry in term of bone-implant interface in two implant systems: an histomorphometrical study.

    Science.gov (United States)

    Rocci, A; Calcaterra, R; DI Girolamo, M; Rocci, M; Rocci, C; Baggi, L

    2015-01-01

    Many factors could affect the osseous healing of implants such as surface topography of biomaterial, the status of the bone/implant site, implant loading conditions, surgical technique and implant design. The aim of this study was to analyze the BIC of 2 different implants systems characterized by different micro and macrogeometry, that were placed in the posterior maxillary and mandibular jaws of humans, clinically unloaded and retrieved for histomorphometric analyses after 12 weeks. The patients were divided in two groups (Group I and II); group I was composed by 4 patients that each received in the posterior areas of mandible one type A implant [GTB-Plan1Health Amaro (UD) Italy] one type B implant (OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). Group II was composed by 3 patients that each received in the posterior areas of jawsbone one type A implant [GTB-Plan1Health Amaro (UD) Italy] one type B implant (OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). After 12 weeks of healing all the implants of both groups were harvested with the peri-implant bone tissues. Osseointegration process was evaluated throughout measurements of BIC. No statistical significance differences were found among the mean percentage of BIC of Group I - type A were 66,51% versus 49,96% in Group I - type B, as well as among the mean percentage of BIC of Group II - type A were 43.7% versus 60.02% in Group II - type B. Our results highlight that the mean percentage of BIC after 12 weeks from the implants placement without functional loading is not influenced by the composition of the implant surface.

  20. Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Mehrnaz Karimi

    1992-04-01

    Full Text Available People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss . In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter, stimulator and receiver, and electrode array.

  1. Treatment of acromegaly by yttrium implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hibbert, J.; Shaheen, O.H.

    1977-01-01

    Yttrium implantation is one of the many ways of treating acromegaly. The advantages are the minor nature of the procedure and the fact that pituitary replacement is not as commonly required as after hypophysectomy. Thus in young female patients menstruation may be resumed following treatment and pregnancy has occurred. The procedure is not as free from complications as external irradiation but the response is more satisfactory.

  2. Ultrastructural study of tissues surrounding replanted teeth and dental implants.

    Science.gov (United States)

    Shioya, Kazuhiro; Sawada, Takashi; Miake, Yasuo; Inoue, Sadayuki; Yanagisawa, Takaaki

    2009-03-01

    The aim of this study was to describe the ultrastructure of the dentogingival border at replanted teeth and implants. Wistar rats (8 weeks old) were divided into groups for replantation and implantation experiments. In the former, the upper right first molars were extracted and then immediately replanted. In the latter, pure titanium implants were used. All tissues were fixed, demineralized and embedded in epoxy resin for ultrastructural observations. One week after replantation, the junctional epithelium was lost, and the oral sulcular epithelium covered the enamel surface. The amount of the epithelium increased in 2 weeks, and resembled the junctional epithelium, and the internal basal lamina and hemidesmosomes were formed in 4 weeks. One week after implantation, peri-implant epithelium was formed, and in 2 and 4 weeks, this epithelium with aggregated connective tissue cells were observed. In 8 weeks, the peri-implant epithelium receded, and aligned special cells with surrounding elongated fibroblasts and bundles of collagen fibers appeared to seal the implant interface. In replantation of the tooth, the internal basal lamina remained at the surface of the enamel of the replanted tooth, which is likely to be related to regeneration of the junctional epithelium and the attachment apparatus at the epithelium-tooth interface. Following implantation, a layer of cells with characteristics of connective tissue cells, but no junctional epithelium and attachment apparatus, was formed to seal the site of the implant.

  3. Facts about food irradiation: Genetic studies

    International Nuclear Information System (INIS)

    1991-01-01

    Results published in the mid-1970s from the National Institute of Nutrition (NIN) in India showed increased numbers of polyploid cells in rats, mice, monkeys and malnourished children fed irradiated wheat products. This fact sheet considers the validity of these results. A large number of independent studies have been subsequently performed, and in none of these have results been obtained that support the NIN findings. The conclusion is that there is no evidence to link the consumption of irradiated food with any mutagenic effect. 3 refs

  4. Placement of single tooth implant in healed socket with immediate temporization: Clinical study

    Directory of Open Access Journals (Sweden)

    Jeevan Lata

    2012-01-01

    Full Text Available Introduction: Edentulous condition inadequately compensated for, by dentures, impair oral function and is accompanied by reduced self–confidence. In a continued effort to achieve these goals, implant dentistry was introduced. Immediate temporization is somehow a recent concept, which allows the maintenance of soft tissue contours, along with interdental alveolar contours. Aims and Obectives: Aims of the present study were to study the placement of implant in the post-extracted healed tooth socket of anterior maxilla and to evaluate the feasibility of early function on implants placed. Materials and Methods: In the present study, HI-TECH IMPLANTS TRX-OP one-piece immediate loading implant system with the built on abutment has been used.Immediate temporisation has been done and results have been evaluated in terms of stability, gingival health, esthetics, marginal bone loss, patient′s psychological attitude, and satisfaction.
Results: Out of eight implants, 6 successfully healed whereas 2 implants suffered failure
Conclusion: Overall conclusion drawn from the study is, immediate temporization is a successful method providing psychological, financial and emotional benefits to the patient.

  5. Silicon exfoliation by hydrogen implantation: Actual nature of precursor defects

    Energy Technology Data Exchange (ETDEWEB)

    Kuisseu, Pauline Sylvia Pokam, E-mail: pauline-sylvia.pokam-kuisseu@cnrs-orleans.fr [CEMHTI-CNRS, 3A, rue de la férollerie, 45071 Orléans (France); Pingault, Timothée; Ntsoenzok, Esidor [CEMHTI-CNRS, 3A, rue de la férollerie, 45071 Orléans (France); Regula, Gabrielle [IM2NP-CNRS-Université d’Aix-Marseille, Avenue Escadrille Normandie Niemen, 13397 Marseille (France); Mazen, Frédéric [CEA-Leti, MINATEC campus, 17, rue des Martyrs, 38054 Grenoble Cedex 9 (France); Sauldubois, Audrey [Université d’Orléans, rue de Chartres – Collegium ST, 45067 Orléans (France); Andreazza, Caroline [ICMN-CNRS-Université d’Orléans, 1b rue de la férollerie, 45071 Orléans (France)

    2017-06-15

    MeV energy hydrogen implantation in silicon followed by a thermal annealing is a very smart way to produce high crystalline quality silicon substrates, much thinner than what can be obtained by diamond disk or wire sawing. Using this kerf-less approach, ultra-thin substrates with thicknesses between 15 µm and 100 µm, compatible with microelectronic and photovoltaic applications are reported. But, despite the benefits of this approach, there is still a lack of fundamental studies at this implantation energy range. However, if very few papers have addressed the MeV energy range, a lot of works have been carried out in the keV implantation energy range, which is the one used in the smart-cut® technology. In order to check if the nature and the growth mechanism of extended defects reported in the widely studied keV implantation energy range could be extrapolated in the MeV range, the thermal evolution of extended defects formed after MeV hydrogen implantation in (100) Si was investigated in this study. Samples were implanted at 1 MeV with different fluences ranging from 6 × 10{sup 16} H/cm{sup 2} to 2 × 10{sup 17} H/cm{sup 2} and annealed at temperatures up to 873 K. By cross-section transmission electron microscopy, we found that the nature of extended defects in the MeV range is quite different of what is observed in the keV range. In fact, in our implantation conditions, the generated extended defects are some kinds of planar clusters of gas-filled lenses, instead of platelets as commonly reported in the keV energy range. This result underlines that hydrogen behaves differently when it is introduced in silicon at high or low implantation energy. The activation energy of the growth of these extended defects is independent of the chosen fluence and is between (0.5–0.6) eV, which is very close to the activation energy reported for atomic hydrogen diffusion in a perfect silicon crystal.

  6. Hydroxyapatite coating on PEEK implants: Biomechanical and histological study in a rabbit model

    Energy Technology Data Exchange (ETDEWEB)

    Durham, John W. [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Montelongo, Sergio A.; Ong, Joo L.; Guda, Teja [Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX 78249 (United States); Allen, Matthew J. [Department of Veterinary Medicine, University of Cambridge, Cambridge (United Kingdom); Rabiei, Afsaneh, E-mail: arabiei@ncsu.edu [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

    2016-11-01

    A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18 weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. - Highlights: • Method for improving osseointegration of PEEK implants is analyzed in vivo. • Uniform multilayer coatings were deposited on cylindrical PEEK implants. • Microwave and hydrothermal heat treatments crystallized the hydroxyapatite coating. • Healing response shows coated implants increase bone growth and implant fixation.

  7. Hydroxyapatite coating on PEEK implants: Biomechanical and histological study in a rabbit model

    International Nuclear Information System (INIS)

    Durham, John W.; Montelongo, Sergio A.; Ong, Joo L.; Guda, Teja; Allen, Matthew J.; Rabiei, Afsaneh

    2016-01-01

    A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18 weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. - Highlights: • Method for improving osseointegration of PEEK implants is analyzed in vivo. • Uniform multilayer coatings were deposited on cylindrical PEEK implants. • Microwave and hydrothermal heat treatments crystallized the hydroxyapatite coating. • Healing response shows coated implants increase bone growth and implant fixation.

  8. Long time follow up of implant therapy and treatment of peri-implantitis.

    Science.gov (United States)

    Roos-Jansåker, Ann-Marie

    2007-01-01

    Dental implants have become an often used alternative to replace missing teeth, resulting in an increasing percentage of the adult population with implant supported prosthesis. Although favourable long-term results of implant therapy have been reported, infections occur. Until recently few reports included data on peri-implant infections, possibly underestimating this complication of implant treatment. It is possible that some infections around implants develop slowly and that with time peri-implantitis will be a common complication to implant therapy as an increasing number of patients have had their implants for a long time (>10 years). Data on treatment of peri-implant lesions are scarce leaving the clinician with limited guidance regarding choice of treatment. The aim of this thesis was to study the frequency of implant loss and presence of peri-implant lesions in a group of patients supplied with Brånemark implants 9-14 years ago, and to relate these events to patient and site specific characteristics. Moreover three surgical treatment modalities for peri-implantitis were evaluated. The thesis is based on six studies; Studies I-III included 218 patients and 1057 implants followed for 9-14 years evaluating prevalence of, and factors related to implant loss (Paper I) and prevalence of peri-implant infections and related factors (Paper I-III). Study IV is a review describing different treatment modalities of peri-implant infections. Study V is a prospective cohort study involving 36 patients and 65 implants, evaluating the use of a bone substitute with or without the use of a resorbable membrane. Study VI is a case series with 12 patients and 16 implants, evaluating a bone substitute in combination with a resorbable membrane and submerged healing. This thesis demonstrated that: After 9-14 years the survival rates of dental implants are high (95.7%). Implant loss seems to cluster within patients and are related to periodontitis evidenced as bone loss on

  9. Bone reactions at implants subjected to experimental peri-implantitis and static load. A study in the dog

    DEFF Research Database (Denmark)

    Gotfredsen, K; Berglundh, T; Lindhe, J

    2002-01-01

    during a 12-week interval, the screws were reactivated. Thus, the model included 3 different experimental sites of each surface group: group M+L (mucositis+load); group P (peri-implantitis); group P+L (peri-implantitis+load). Fluorochrome labels were injected and standardized radiographs obtained....... The animals were sacrificed and block biopsies of all implant sites dissected and prepared for histological analysis. RESULTS: It was demonstrated that the lateral static load failed to induce peri-implant bone loss at implants with mucositis and failed to enhance the bone loss at implants with experimental...... peri-implantitis. The proportion of bone labels and the bone density in the interface zone were significantly higher in group P+L than in group P. CONCLUSION: It is suggested that a lateral static load with controlled forces may not be detrimental to implants exhibiting mucositis or peri-implantitis....

  10. TEM studies of P+ implanted and subsequently laser annealed Si

    International Nuclear Information System (INIS)

    Sadana, D.K.; Wilson, M.C.; Booker, G.R.; Washburn, J.

    1979-05-01

    The present investigation is concerned with laser annealing of P + implanted Si. The aim of the work was to study the crystallization behavior of damage structure occurring due to high dose rate implantation using transmission electron microscopy (TEM) as the method of examination

  11. A study of photoluminescence and micro-Raman scattering in C-implanted GaN

    International Nuclear Information System (INIS)

    Zhang Limin; Zhang Xiaodong; Liu Zhengmin

    2010-01-01

    GaN samples (no yellow luminescence) in their as-grown states were implanted with 10 13 -10 17 C ions/cm 2 and studied by photoluminescence spectra and micro-Raman scattering spectra. The photoluminescence study showed that yellow luminescence were produced in the C-implanted GaN after 950 degree C annealing, and the peaks of the near band edge emissions showed blue-shifts after C implantation. The Raman measurements indicated that the stresses in GaN films did not change after C implantation. The samples implanted with 10 15 cm -2 carbon ions had the Raman peak at 300 cm -1 , which is associated to the disorder-activated Raman scattering. However, further increasing the implantation dose resulted decreased intensity of the 300 cm -1 peak, due to the ion beam current increase with the implantation dose. (authors)

  12. Systemic alendronate treatment improves fixation of press-fit implants: a canine study using nonloaded implants

    DEFF Research Database (Denmark)

    Jensen, Thomas B; Bechtold, Joan E; Chen, Xinqian

    2007-01-01

    of alendronate treatment. Bone ongrowth (bone in contact with implant surface) was estimated using the linear intercept technique and shear strength was calculated as the slope on a load-displacement curve. For the press fit implants, alendronate treatment significantly increased bone ongrowth from 24% to 29...... early implant stability is an important predictor of longevity, systemic alendronate treatment could be an important clinical tool to positively influence the early stages of implant incorporation. Udgivelsesdato: 2007-Jun...

  13. Biodegradable magnesium-based implants in bone studied by synchrotron radiation microtomography

    Science.gov (United States)

    Moosmann, Julian; Zeller-Plumhoff, Berit; Wieland, D. C. Florian; Galli, Silvia; Krüger, Diana; Dose, Thomas; Burmester, Hilmar; Wilde, Fabian; Bech, Martin; Peruzzi, Niccolò; Wiese, Björn; Hipp, Alexander; Beckmann, Felix; Hammel, Jörg; Willumeit-Römer, Regine

    2017-09-01

    Permanent implants made of titanium or its alloys are the gold standard in many orthopedic and traumatological applications due to their good biocompatibility and mechanical properties. However, a second surgical intervention is required for this kind of implants as they have to be removed in the case of children that are still growing or on patient's demand. Therefore, magnesium-based implants are considered for medical applications as they are degraded under physiological conditions. The major challenge is tailoring the degradation in a manner that is suitable for a biological environment and such that stabilization of the bone is provided for a controlled period. In order to understand failure mechanisms of magnesium-based implants in orthopedic applications and, further, to better understand the osseointegration, screw implants in bone are studied under mechanical load by means of a push-out device installed at the imaging beamline P05 of PETRA III at DESY. Conventional absorption contrast microtomography and phasecontrast techniques are applied in order to monitor the bone-to-implant interface under increasing load conditions. In this proof-of-concept study, first results from an in situ push-out experiment are presented.

  14. From isolation and dependence to autonomy - expectations before and experiences after cochlear implantation in adult cochlear implant users and their significant others.

    Science.gov (United States)

    Mäki-Torkko, Elina Margareetta; Vestergren, Sara; Harder, Henrik; Lyxell, Björn

    2015-01-01

    The aim of the study was to examine pre-operative expectations and the post-operative experiences related to cochlear implants (CI) in CI-users and their significant others. A questionnaire was used and the responses were analysed by means of The Qualitative Content Analysis. All adults implanted between 1992 and 2010, who had had their implants for a minimum of 12 months (n = 120) were contacted. Response rate was high (90.8%), and all-inclusive answers were received from 101 CI-users (84.2%). The overall sense of increased well-being and life satisfaction was described as having lived in two different worlds, one with the auditory stimulation and one without. In the overall sense of increased well-being and satisfaction three interwoven subcategories, alienation - normality, fear - autonomy, and living a social life emerged. When CI-users and their significant others recalled the time prior to receiving the CI, a sense of fear was present with origins in the concern for the respondents' (CI-users) ability to cope and care independently in society. Conversely, after the implantation both parties emphasized the notion of a distinct transformation within the CI-user towards autonomy. Communication was highlighted as a large part of living social life. The CI increases well-being and satisfaction for both CI-users and their significant others, which is especially evident regarding enhanced autonomy, normality and living social life. Before implantation it is important to discuss the fact that phone calls and listening to music are improvement expectations that might not be met by the CI. The perceived life changes affect the lives of both the CI-users and the significant others, a finding important to take into consideration before implantation and during rehabilitation after the implantation. Before implantation it is important to inform both CI-recipients and significant others about the length of time required to be able to hear selectively after the

  15. Effects of Reinforcement on Denture Strain in Maxillary Implant Overdentures: An In Vitro Study Under Various Implant Configurations.

    Science.gov (United States)

    Takahashi, Toshihito; Gonda, Tomoya; Maeda, Yoshinobu

    Maxillary implant overdentures are often designed without palatal coverage to maximize wearer comfort. Although palateless dentures have been reported to be less rigid than conventional dentures, and require reinforcement to prevent complications, there is little documentation about the effects of such reinforcement. The purpose of this study was to examine the effects of reinforcement on the strain on maxillary implant overdentures supported by implants in a variety of configurations. A maxillary edentulous model with implants inserted in the anterior, premolar, and molar area was fabricated. Five types of experimental overdentures, with and without reinforcement, were fabricated, and two strain gauges were attached at the anterior midline of the labial and palatal sides. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the shear strain on the denture was measured. The measurements were compared using the Kruskal-Wallis test (P = .05). On both the labial and palatal sides, the strain on the palateless dentures with reinforcement was significantly lower than the strain on palateless dentures without reinforcement in all implant configurations (P overdenture with residual ridge reinforcement and a palatal bar could reduce the strain in the anterior midline to almost the same level as a denture with palatal coverage. This type of reinforcement may prevent prosthetic and implant complications.

  16. Osseointegration of a 3D Printed Stemmed Titanium Dental Implant: A Pilot Study

    Directory of Open Access Journals (Sweden)

    James Tedesco

    2017-01-01

    Full Text Available In this pilot study, a 3D printed Grade V titanium dental implant with a novel dual-stemmed design was investigated for its biocompatibility in vivo. Both dual-stemmed (n = 12 and conventional stainless steel conical (n = 4 implants were inserted into the tibial metaphysis of New Zealand white rabbits for 3 and 12 weeks and then retrieved with the surrounding bone, fixed, dehydrated, and embedded into epoxy resin. The implants were analyzed using correlative histology, microcomputed tomography, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The histological presence of multinucleated osteoclasts and cuboidal osteoblasts revealed active bone remodeling in the stemmed implant starting at 3 weeks and by 12 weeks in the conventional implant. Bone-implant contact values indicated that the stemmed implants supported bone growth along the implant from the coronal crest at both 3- and 12-week time periods and showed bone growth into microporosities of the 3D printed surface after 12 weeks. In some cases, new bone formation was noted in between the stems of the device. Conventional implants showed mechanical interlocking but did have indications of stress cracking and bone debris. This study demonstrates the comparable biocompatibility of these 3D printed stemmed implants in rabbits up to 12 weeks.

  17. Osseointegration of a 3D Printed Stemmed Titanium Dental Implant: A Pilot Study.

    Science.gov (United States)

    Tedesco, James; Lee, Bryan E J; Lin, Alex Y W; Binkley, Dakota M; Delaney, Kathleen H; Kwiecien, Jacek M; Grandfield, Kathryn

    2017-01-01

    In this pilot study, a 3D printed Grade V titanium dental implant with a novel dual-stemmed design was investigated for its biocompatibility in vivo. Both dual-stemmed ( n  = 12) and conventional stainless steel conical ( n  = 4) implants were inserted into the tibial metaphysis of New Zealand white rabbits for 3 and 12 weeks and then retrieved with the surrounding bone, fixed, dehydrated, and embedded into epoxy resin. The implants were analyzed using correlative histology, microcomputed tomography, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The histological presence of multinucleated osteoclasts and cuboidal osteoblasts revealed active bone remodeling in the stemmed implant starting at 3 weeks and by 12 weeks in the conventional implant. Bone-implant contact values indicated that the stemmed implants supported bone growth along the implant from the coronal crest at both 3- and 12-week time periods and showed bone growth into microporosities of the 3D printed surface after 12 weeks. In some cases, new bone formation was noted in between the stems of the device. Conventional implants showed mechanical interlocking but did have indications of stress cracking and bone debris. This study demonstrates the comparable biocompatibility of these 3D printed stemmed implants in rabbits up to 12 weeks.

  18. Clinical and microbiological characteristics of peri-implantitis cases: a retrospective multicentre study.

    Science.gov (United States)

    Charalampakis, G; Leonhardt, Å; Rabe, P; Dahlén, G

    2012-09-01

    The aim of this study was to follow patient cases retrospectively in a longitudinal manner from the time of implant placement to the time they were diagnosed with peri-implant disease, and to identify associated clinical and microbiological features of peri-implant disease. A total of 281 patient cases were chosen from the archives of the Oral Microbiological Diagnostic Laboratory, Gothenburg, Sweden, based on bacterial samples taken from diseased implants. A form was designed and filled in separately for each case including data on patient, implant and disease profile. Most cases were severe peri-implantitis cases (91.4%). In 41.3% of the patients, peri-implantitis was developed early, already after having implants in function less than 4 years. The type of implant surface was significantly associated with the time in years implants were in function, before disease was developed (P < 0.05). The microbiological results by both culture and checkerboard analysis, although failed to fully correspond to the severity of the disease in terms of magnitude, proved to show that peri-implantitis is a polymicrobial anaerobic infection with increased number of AGNB (aerobic Gram-negative bacilli) in 18.6% of the patients. Peri-implantitis is a biological complication of implants in function that poses a threat to their long-term survival. It may develop earlier around implants with rough surfaces and it may represent a true infection. Microbiological sampling methods should be improved and uniformed so as to fully unveil the microbiological profile of the disease. © 2011 John Wiley & Sons A/S.

  19. Six-year clinical outcome of single implant-retained mandibular overdentures--a pilot study.

    Science.gov (United States)

    Passia, Nicole; Wolfart, Stefan; Kern, Matthias

    2015-10-01

    The aim of this prospective pilot study was to evaluate the prosthodontic maintenance as well as the implant outcome of single implant-retained mandibular overdentures over an observation period of 6 years. Eleven edentulous patients received one single implant in the midline of the mandible. Denture bases were temporarily relined and 2 months later provided with a ball attachment for implant retention. Implant related parameters and prosthodontic maintenance interventions were assessed 4 weeks after implant loading and then once a year. Over a mean observation period of 75.9 months, no implant was lost. The most frequent prosthetic maintenance intervention was activation of the matrix due to loss of retention, followed by exchange of the female part. Eight denture bases had to be repaired after a fracture in the midline area. Within the limitations of this preliminary clinical study, the concept of a single midline implant to retain a mandibular complete denture was a successful treatment option for elderly edentulous patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Design Considerations for Developing Biodegradable Magnesium Implants

    Science.gov (United States)

    Brar, Harpreet S.; Keselowsky, Benjamin G.; Sarntinoranont, Malisa; Manuel, Michele V.

    The integration of biodegradable and bioabsorbable magnesium implants into the human body is a complex undertaking that faces major challenges. The complexity arises from the fact that biomaterials must meet both engineering and physiological requirements to ensure the desired properties. Historically, efforts have been focused on the behavior of commercial magnesium alloys in biological environments and their resultant effect on cell-mediated processes. Developing causal relationships between alloy chemistry and micro structure, and its effect on cellular behavior can be a difficult and time intensive process. A systems design approach driven by thermodynamics has the power to provide significant contributions in developing the next generation of magnesium alloy implants with controlled degradability, biocompatibility, and optimized mechanical properties, at reduced time and cost. This approach couples experimental research with theory and mechanistic modeling for the accelerated development of materials. The aim of this article is to enumerate this strategy, design considerations and hurdles for developing new magnesium alloys for use as biodegradable implant materials [1].

  1. Feasibility study of self-lubrication by chlorine implantation

    International Nuclear Information System (INIS)

    Akhajdenung, T.; Aizawa, T.; Yoshitake, M.; Mitsuo, A.

    2003-01-01

    Implantation of chlorine into titanium nitride (TiN) coating on the high-speed steel substrate has succeeded in significant reduction of wear rate and friction coefficient for original TiN under dry wear condition. Through precise investigation on the surface reaction in the wear track, in situ formation of oxygen-deficient titanium oxides was found to play a role as a lubricious oxide. In the present paper, this self-lubrication mechanism is further investigated for various wearing conditions. For wide range of sliding speed and normal load in the wear map, the wear volume of a counter material is actually reduced with comparison to the un-implanted TiN. Effect of the ion implantation dose on this self-lubrication mechanism is also studied for practical use. Some comments are made on further application of this self-lubrication to manufacturing

  2. Sheet resistance effects in mercury cadmium telluride implanted photodiodes

    International Nuclear Information System (INIS)

    Fiorito, G.; Gasparrini, G.; Svelto, F.

    1977-01-01

    The frequency response of Hg + implanted Hgsub(1-x)Cdsub(x)Te photodiodes is discussed. This analysis, evaluating both the response to fast laser pulses and the 3 dB rolloff of the diode shot-noise spectrum, showed the necessity of adopting a distributed equivalent circuit model taking into account the implanted layer sheet resistance. Frequency behaviour, in fact, proved not to match a simple p-n junction model based on a lumped standard equivalent circuit. On this basis apparent anomalies previously reported can be explained, and useful suggestions can be obtained for design and fabrication of fast detectors. (author)

  3. Risk of lymphoma in women with breast implants: analysis of clinical studies.

    Science.gov (United States)

    Largent, Joan; Oefelein, Michael; Kaplan, Hilton M; Okerson, Ted; Boyle, Peter

    2012-05-01

    Large studies suggest that the overall rate of lymphoma in women with breast implants is no greater than in the general population; clinical reports suggest an association between breast implants and the rare non-Hodgkin lymphoma, anaplastic large cell lymphoma (ALCL). Observed cases of lymphoma reported in Allergan-sponsored breast implant clinical studies were compared with expected cases on the basis of the incidence of lymphoma among women in the National Cancer Institute's Surveillance Epidemiology and End Results program, using standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). In clinical studies, there were 28 observed cases of lymphoma among 89 382 patients and 204 682 person-years of follow-up compared with 43 expected cases [SIR: 28/43=0.65 (95% CI: 0.43-0.94), P=0.02]. SIRs were calculated stratifying by baseline cancer history: women without prior cancer [SIR: 17/24=0.70 (95% CI: 0.41-1.13), P=0.17] and women with prior cancer [SIR: 11/14=0.79 (95% CI: 0.39-1.41), P=0.52]. SIRs were calculated by implant shell type: textured shell implants [SIR: 16/23=0.70 (95% CI: 0.40-1.13), P=0.16] and smooth shell implants [SIR: 12/19=0.63 (95% CI: 0.33-1.10), P=0.12]. Surveillance Epidemiology and End Results reported 12 cases of primary breast ALCL in women between 1996 and 2007 without a history of cancer, for an average annual incidence of 4.28 (95% CI: 3.51-5.05)/100 million women in the US - these women may or may not have breast implants. In clinical studies, three ALCL cases were reported in women with breast implants and a history of breast cancer, yielding a crude incidence rate of 1.46 (95% CI: 0.30-4.3)/100 000 person-years. Large clinical studies, based on over 200 000 person-years of follow-up, suggest no evidence of an increased risk of lymphoma among women who have received breast implants.

  4. Recoil implantation of boron into silicon by high energy silicon ions

    Science.gov (United States)

    Shao, L.; Lu, X. M.; Wang, X. M.; Rusakova, I.; Mount, G.; Zhang, L. H.; Liu, J. R.; Chu, Wei-Kan

    2001-07-01

    A recoil implantation technique for shallow junction formation was investigated. After e-gun deposition of a B layer onto Si, 10, 50, or 500 keV Si ion beams were used to introduce surface deposited B atoms into Si by knock-on. It has been shown that recoil implantation with high energy incident ions like 500 keV produces a shallower B profile than lower energy implantation such as 10 keV and 50 keV. This is due to the fact that recoil probability at a given angle is a strong function of the energy of the primary projectile. Boron diffusion was showed to be suppressed in high energy recoil implantation and such suppression became more obvious at higher Si doses. It was suggested that vacancy rich region due to defect imbalance plays the role to suppress B diffusion. Sub-100 nm junction can be formed by this technique with the advantage of high throughput of high energy implanters.

  5. Positron and nanoindentation study of helium implanted high chromium ODS steels

    Science.gov (United States)

    Veternikova, Jana Simeg; Fides, Martin; Degmova, Jarmila; Sojak, Stanislav; Petriska, Martin; Slugen, Vladimir

    2017-12-01

    Three oxide dispersion strengthened (ODS) steels with different chromium content (MA 956, MA 957 and ODM 751) were studied as candidate materials for new nuclear reactors in term of their radiation stability. The radiation damage was experimentally simulated by helium ion implantation with energy of ions up to 500 keV. The study was focused on surface and sub-surface structural change due to the ion implantation observed by mostly non-destructive techniques: positron annihilation lifetime spectroscopy and nanoindentation. The applied techniques demonstrated the best radiation stability of the steel ODM 751. Blistering effect occurred due to high implantation dose (mostly in MA 956) was studied in details.

  6. Pectin nanocoating of titanium implant surfaces - an experimental study in rabbits

    DEFF Research Database (Denmark)

    Gurzawska, Katarzyna Aleksandra; Dirscherl, Kai; Jørgensen, Bodil

    2017-01-01

    that may increase adhesion of bone proteins, and bone cells at the implant surface. Nanocoating with pectins, plant cell wall-derived polysaccharides, is frequently done using rhamnogalacturonan-I (RG-I). AIM: The aim of the study was to evaluate the effect of nanocoating titanium implants with plant cell...... wall-derived rhamnogalacturonan-I, on bone healing and osseointegration. MATERIAL AND METHODS: Machined titanium implants were coated with three modifications of rhamnogalacturonan-I (RG-I). Chemical and physical surface properties were examined before insertion of nanocoated implants (n = 96....... The bone response to the nanocoated implants was analyzed qualitatively and quantitatively after 2, 4, 6, and 8 weeks of healing using light microscopy and histomorphometric methods. RESULTS: The RG-I coating influenced the surface chemical composition; wettability and roughness, making the surface more...

  7. Comparative study of longitudinal changes in peri-implant bone microstructure

    International Nuclear Information System (INIS)

    Suzuki, Yusuke; Matsunaga, Satoru; Abe, Shinichi; Ide, Yoshinobu; Usami, Akinobu

    2010-01-01

    The load applied to an implant is directly transmitted to the jaw and is considered to be one of the causes of remodeling of internal trabecular bones. However, the longitudinal changes during loading and the rearrangement of the trabecular bone structure are mostly unknown. The aim of this study was to clarify the changes in internal jaw bone structure longitudinally during natural tooth eruption as well as tooth extraction and post-implantation periods in a dog model by micro computed tomography (micro-CT). Maxillae of 16 male beagle dogs were used in this study. First, 4 dogs with all maxillary molar teeth erupted were euthanized as a control group. Next, 6 teeth consisting of the bilateral maxillary fourth premolars, and first and second molars were extracted from each of the 12 dogs. Then, 4 dogs of the tooth-extracted group were euthanized 3 months after extraction of the teeth. At this time, three implants were inserted in the left side of the maxilla of the remaining 8 dogs, and the superstructures were placed after 3 months. Four of these 8 dogs with implants were euthanized at 3 months and the other 4 at 1 year after placement of the superstructure. Then, the maxillary bone was removed from each dog as a specimen and sequential micro-CT images were taken. After reconstruction of three-dimensional images, morphological and metrical observation of the jaw trabecular bone structure was performed. A decrease of the trabecular bone in the tooth-extracted group was morphologically and morphometrically observed, whereas the implanted group showed thick, rich trabecular bone. Although a longitudinal decrease in the bone tissue volume was recognized both in the tooth-extracted and the implanted groups, the amount was smaller in the implanted group than in the tooth-extracted group. The results suggested that the application of load by implants in the case of tooth loss inhibits resorption of the alveolar bone and prevents thinning of the jaw. (author)

  8. Age at implantation and auditory memory in cochlear implanted children.

    Science.gov (United States)

    Mikic, B; Miric, D; Nikolic-Mikic, M; Ostojic, S; Asanovic, M

    2014-05-01

    Early cochlear implantation, before the age of 3 years, provides the best outcome regarding listening, speech, cognition an memory due to maximal central nervous system plasticity. Intensive postoperative training improves not only auditory performance and language, but affects auditory memory as well. The aim of this study was to discover if the age at implantation affects auditory memory function in cochlear implanted children. A total of 50 cochlear implanted children aged 4 to 8 years were enrolled in this study: early implanted (1-3y) n = 27 and late implanted (4-6y) n = 23. Two types of memory tests were used: Immediate Verbal Memory Test and Forward and Backward Digit Span Test. Early implanted children performed better on both verbal and numeric tasks of auditory memory. The difference was statistically significant, especially on the complex tasks. Early cochlear implantation, before the age of 3 years, significantly improve auditory memory and contribute to better cognitive and education outcomes.

  9. Drug Facts

    Medline Plus

    Full Text Available ... Facts Bath Salts Facts Cocaine (Coke, Crack) Facts Heroin (Smack, Junk) Facts Marijuana (Weed, Pot) Facts MDMA ( ... Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/ ...

  10. Bone implant sockets made using three different procedures: a stability study in dogs

    Science.gov (United States)

    Campo, Julián

    2012-01-01

    Objective: This study compared the effects of three different methods of preparing bone implant sockets (drilling, osteotomes, and piezoelectric device) on osseointegration using resonance frequency analysis (RFA). Study Design: An experimental prospective study was designed. Material and Methods: Ten adult beagle dogs were studied. After 5 weeks, 23 out of 28 initially placed implants in the iliac crest were evaluated, comparing these three different procedures of bone implant socket. Student’s t-test (paired, two-tailed) was used to reveal differences among the three groups at each time point (SPSS 16.0, IL, USA). Results: After a 5-week healing period, the implants placed in sockets that were made using an osteotome or piezoelectric device were slightly more stable than those made by drilling. Reduced mechanical and heat injury to the bone is beneficial for maintaining and improving stability during the critical early healing period. Conclusion: Using RFA, there was evidence of a slight increase in implant stability in the iliac crest after 5 weeks of healing when the implant socket was made using a piezoelectric device or expansion procedure as compare with the drilling method. Key words:Bone implant sockets, drilling, osteotomes, piezoelectric, resonance frequency analysis, stability. PMID:24558558

  11. Investigation of pathogenic genes in peri-implantitis from implant clustering failure patients: a whole-exome sequencing pilot study.

    Directory of Open Access Journals (Sweden)

    Soohyung Lee

    Full Text Available Peri-implantitis is a frequently occurring gum disease linked to multi-factorial traits with various environmental and genetic causalities and no known concrete pathogenesis. The varying severity of peri-implantitis among patients with relatively similar environments suggests a genetic aspect which needs to be investigated to understand and regulate the pathogenesis of the disease. Six unrelated individuals with multiple clusterization implant failure due to severe peri-implantitis were chosen for this study. These six individuals had relatively healthy lifestyles, with minimal environmental causalities affecting peri-implantitis. Research was undertaken to investigate pathogenic genes in peri-implantitis albeit with a small number of subjects and incomplete elimination of environmental causalities. Whole-exome sequencing was performed on collected saliva samples via self DNA collection kit. Common variants with minor allele frequencies (MAF > = 0.05 from all control datasets were eliminated and variants having high and moderate impact and loss of function were used for comparison. Gene set enrichment analysis was performed to reveal functional groups associated with the genetic variants. 2,022 genes were left after filtering against dbSNP, the 1000 Genomes East Asian population, and healthy Korean randomized subsample data (GSK project. 175 (p-value <0.05 out of 927 gene sets were obtained via GSEA (DAVID. The top 10 was chosen (p-value <0.05 from cluster enrichment showing significance of cytoskeleton, cell adhesion, and metal ion binding. Network analysis was applied to find relationships between functional clusters. Among the functional groups, ion metal binding was located in the center of all clusters, indicating dysfunction of regulation in metal ion concentration might affect cell morphology or cell adhesion, resulting in implant failure. This result may demonstrate the feasibility of and provide pilot data for a larger research

  12. Variable energy positron beam study of Xe-implanted uranium oxide

    International Nuclear Information System (INIS)

    Djourelov, Nikolay; Marchand, Benoît; Marinov, Hristo; Moncoffre, Nathalie; Pipon, Yves; Nédélec, Patrick; Toulhoat, Nelly; Sillou, Daniel

    2013-01-01

    Doppler broadening of annihilation gamma-line combined with a slow positron beam was used to measure the momentum density distribution of annihilating pair in a set of sintered UO 2 samples. The influence of surface polishing, of implantation with 800-keV 136 Xe 2+ at fluences of 1 × 10 15 and 1 × 10 16 Xe cm −2 , and of annealing were studied by following the changes of the momentum distribution shape by means of S and W parameters. The program used for this purpose was VEPFIT. At the two fluences in the stoichiometric as-implanted UO 2 , formation of Xe bubbles was not detected. The post-implantation annealing and over-stoichiometry in the as-implanted sample caused Xe precipitation and formation of Xe bubbles.

  13. Implants in free fibula flap supporting dental rehabilitation - Implant and peri-implant related outcomes of a randomized clinical trial.

    Science.gov (United States)

    Kumar, Vinay V; Ebenezer, Supriya; Kämmerer, Peer W; Jacob, P C; Kuriakose, Moni A; Hedne, Naveen; Wagner, Wilfried; Al-Nawas, Bilal

    2016-11-01

    The objective of this study was to assess the difference in success rates of implants when using two or four implant-supported-overdentures following segmental mandibular reconstruction with fibula free flap. This prospective, parallel designed, randomized clinical study was conducted with 1:1 ratio. At baseline, all participants already had segmental reconstruction of mandible with free fibula flap. The participants were randomized into two groups: Group-I received implant-supported-overdentures on two tissue-level implants and Group-II received implant-supported-overdentures on four tissue-level implants. Success rates of the implants were evaluated at 3 months, 6 months and 12 months following implant loading using marginal bone level changes as well as peri-implant indices (Buser et al., 1990). 52 patients were randomized into two treatment groups (26 each), out of which 18 patients (36 implants) of Group-I and 17 patients (68 implants) of Group-II were evaluated. One implant in Group-I was lost due to infective complications and one patient in the same group had superior barrel necrosis. There was a statistically significant increase at both time points (p = 0.03, p = 0.04 at 6 months, 12 months) in the amount of marginal bone loss in Group-I (0.4 mm, 0.5 mm at 6 months, 12 months) as compared to Group-II (0.1 mm, 0.2 mm at 6 months, 12 months). There were no clinically significant changes peri-implant parameters between both groups. Peri-implant soft tissue hyperplasia was seen in both groups, 32% of implants at 3-months, 26% at 6-months and 3% at 12-months follow-up. The results of this study show that patients with 2-implant-supported-overdentures had higher marginal bone loss as compared to patients with 4-implant-supported-overdentures. There were no clinically significant differences in peri-implant soft tissue factors in patients with 2- or 4-implant-supported-overdentures. Hyperplastic peri-implant tissues are common in the early implant

  14. Nonlinear model of high-dose implantation

    International Nuclear Information System (INIS)

    Danilyuk, A.

    2001-01-01

    The models of high-dose implantation, using the distribution functions, are relatively simple. However, they must take into account the variation of the function of distribution of the implanted ions with increasing dose [1-4]. This variation takes place owing to the fact that the increase of the concentration of the implanted ions results in a change of the properties of the target. High-dose implantation is accompanied by sputtering, volume growth, diffusion, generation of defects, formation of new phases, etc. The variation of the distribution function is determined by many factors and is not known in advance. The variation within the framework of these models [1-4] is taken into account in advance by the introduction of intuitive assumptions on the basis of implicit considerations. Therefore, these attempts should be regarded as incorrect. The model prepared here makes it possible to take into account the sputtering of the target, volume growth and additional declaration on the implanted ions. Without any assumptions in relation to the variation of the distribution function with increasing dose. In our model it is assumed that the type of distribution function for small doses in a pure target substance is the same as in substances with implanted ions. A second assumption relates to the type of the distribution function valid for small doses in the given substances. These functions are determined as a result of a large number of theoretical and experimental investigations and are well-known at the present time. They include the symmetric and nonsymmetric Gauss distribution, the Pearson distribution, and others. We examine implantation with small doses of up to 10 14 - 10 15 cm -2 when the accurately known distribution is valid

  15. Two-stage implant placement technique for the management of irradiated jaws: An animal study.

    Science.gov (United States)

    Aboushelib, Moustafa N; Arnaout, Mohamed A; Elsafi, Mohamed H; Kassem, Youssef M

    2017-10-01

    Radiotherapy results in diminished bone remodeling capacity and an elevated risk of osteoradionecrosis, which can negatively influence the survival rate of dental implants. Patients receiving radiotherapy are advised not to receive dental implants during or soon after completing their radiotherapy. The purpose of this animal study was to investigate a 2-stage implant placement technique designed to diminish applied trauma on irradiated bone. Two groups of white New Zealand rabbits received radiotherapy in ascending doses (2, 4, 8 Gy), while a nonirradiated group served as control. Three weeks after completion of the last radiotherapy session, one of the irradiated groups and the control group received titanium dental implants bilaterally in the femur head. For the second irradiated group, an osteotomy was performed, and the surgical wound was left to heal for 2 weeks before implant placement. All animals were sacrificed 4 weeks after implant placement, and histomorphometric analysis was used to study bone-implant contact (n=14, α=.05). Statistical analysis revealed significantly higher (F=159, P<.001) bone-implant contact in the 2-stage (40.2 ±1.9) implant placement technique than in the immediately placed implants (21.2 ±2.3) in irradiated bone. Both of the groups had a significantly lower bone-to-implant contact ratio than the non-irradiated control (64.2 ±3.8). Within the limitations of this animal study, the 2-stage implant placement technique could be used to reduce trauma in irradiated bone and to improve wound healing around dental implants. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  16. Bone Response to Two Dental Implants with Different Sandblasted/Acid-Etched Implant Surfaces: A Histological and Histomorphometrical Study in Rabbits

    Directory of Open Access Journals (Sweden)

    Antonio Scarano

    2017-01-01

    Full Text Available Background. Scientific evidence in the field of implant dentistry of the past 20 years established that titanium rough surfaces have shown improved osseointegration rates. In a majority of dental implants, the surface microroughness was obtained by grit blasting and/or acid etching. The aim of the study was to evaluate in vivo two different highly hydrophilic surfaces at different experimental times. Methods. Calcium-modified (CA and SLActive surfaces were evaluated and a total of 18 implants for each type of surface were positioned into the rabbit articular femoral knee-joint in a split model experiment, and they were evaluated histologically and histomorphometrically at 15, 30, and 60 days of healing. Results. Bone-implant contact (BIC at the two-implant surfaces was significantly different in favor of the CA surface at 15 days (p=0.027, while SLActive displayed not significantly higher values at 30 (p=0.51 and 60 days (p=0.061. Conclusion. Both implant surfaces show an intimate interaction with newly formed bone.

  17. [Study on Microbial Diversity of Peri-implantitis Subgingival by High-throughput Sequencing].

    Science.gov (United States)

    Li, Zhi-jie; Wang, Shao-guo; Li, Yue-hong; Tu, Dong-xiang; Liu, Shi-yun; Nie, Hong-bing; Li, Zhi-qiang; Zhang, Ju-mei

    2015-07-01

    To study microbial diversity of peri-implantitis subgingival with high-throughput sequencing, and investigate microbiological etiology of peri-implantitis. Subgingival plaques were sampled from the patients with peri-implantitis (D group) and non-peri-implantitis subjects (N group). The microbiological diversity of the subgingival plaques was detected by sequencing V4 region of 16S rRNA with Illumina Miseq platform. The diversity of the community structure was analyzed using Mothur software. A total of 156 507 gene sequences were detected in nine samples and 4 402 operational taxonomic units (OTUs) were found. Selenomonas, Pseudomonas, and Fusobacterium were dominant bacteria in D group, while Fusobacterium, Veillonella and Streptococcus were dominant bacteria in N group. Differences between peri-implantitis and non-peri-implantitis bacterial communities were observed at all phylogenetic levels by LEfSe, which was also found in PcoA test. The occurrence of peri-implantitis is not only related to periodontitis pathogenic microbe, but also related with the changes of oral microbial community structure. Treponema, Herbaspirillum, Butyricimonas and Phaeobacte may be closely related to the occurrence and development of peri-implantitis.

  18. Immediate vs. delayed endosseous integration of maxi implants: a torque removal animal study

    Directory of Open Access Journals (Sweden)

    Hanif Allahbakhshi

    2017-06-01

    Full Text Available Background. Delayed loading is one of the concerns in implant patients. Immediate loading can solve the problem and make patients more satisfied. The present study aimed to compare the removal torque of maxi implants under different loading (immediate and delayed patterns. Methods. This split-mouth experimental study included 2 dogs. Impressions were made and then all the premolars were extracted under general anesthesia. After a three-month healing period, 3 implants were inserted in each quadrant (a total of 12 implants. Anterior and posterior implants (the case group were splinted by an acrylic temporary bridge in order to make the middle implants (the control group off the occlusion. The dogs were sacrificed after 6 weeks and bone blocks were submitted for removal torque test. Data were analyzed with ANOVA (P<0.05. Results. Mean torque values for the cases and control groups were 46.82±25.58 and 59.88±15.19, respectively (P=0.582; not significant. Conclusion. It may be concluded that immediate loading does not reduce the reverse torque values of maxi implants. This supports the advantages of immediate loading for maxi implants.

  19. Overview of Implant Infections in Orthopaedics Department: Retrospective Study

    Directory of Open Access Journals (Sweden)

    Tugrul Bulut

    2014-12-01

    Full Text Available In this study, our aim was to evaluate the antibiotic susceptibility of bacteria isolated from orthopedic implant infections. Within two years operated 1996 patients in an orthopedics and traumatology clinic were retrospectively investigated. Seventy-six (76/1996, 3.8% orthopedic implant infections were detected. Isolated bacteria and their antibiotic susceptibility patterns were analyzed. The bacteries isolated from implant related infections and antibiotic sensitivity patterns were evaluated retrospectively in our orthopaedics and traumatology clinic. Staphylococcus aureus was the predominant organism (30.3%. Gram negative bacterias were isolated in 65.8% of our patients. No resistance was determined against vancomycin and linezolid in gram positive bacterias. Imipenem, amicasin and cefepim was seen as the most effective antibiotics for gram negative bacterias.

  20. Maxillary overdentures retained by splinted and unsplinted implants : A retrospective study

    NARCIS (Netherlands)

    Narhi, TO; Hevinga, M; Voorsmit, RACA; Kalk, W

    2001-01-01

    The purpose of this retrospective study was to evaluate the clinical performance of and patients' satisfaction with maxillary overdentures retained by splinted and unsplinted implants. Patients who had been treated with maxillary implant-retained overdentures because of functional problems with

  1. Computer-aided insertion of endosteal implants in the zygoma: a pilot study

    Science.gov (United States)

    Birkfellner, Wolfgang; Watzinger, Franz; Wanschitz, Felix; Ziya, F.; Kremser, J.; Potyka, A.; Mayr, R.; Huber, Klaus; Kainberger, F.; Ewers, Rolf; Bergmann, Helmar

    2000-04-01

    Endosteal implants facilitate obturator prosthesis fixation in tumor patients after maxillectomy. Previous clinical studies shown however, that survival of implants placed into available bone after maxillectomy is generally poor. Implants positioned optimally in residual zygomatic bone provide superior stability form a biomechanical point of view as well as improved survival. In a pilot study, we have assessed the precision of VISIT, a surgical navigation system developed for research purposes at our institution. VISIT is based on the AVW-library and a number of in-house developed algorithms for communication with an optical tracker and patient-to-CT-registration. The final platform independent application was assembled within 6 man-months using ANSI-C and Tcl/Tk. Five cadaver specimens underwent hemimaxillectomy. The cadaver head was matched to a preoperative high resolution CT by using implanted surgical microscrews as fiducial markers. The position of a surgical drill relative to the cadaver head was determined with an optical tracking system. Implants were placed into the zygomatic arch where maximum bone volume was available. The results were assessed using test for allocation accuracy and postoperative CT-scans of the cadaver specimens. The average allocation accuracy of landmarks on the bony skull was 0.6 +/- 0.3 mm determined with a 5 degree-of-freedom pointer probe. The allocation accuracy of the tip of the implant burr was 1.7 +/- 0.4 mm. The accuracy of the implant position compared to the planned position was 1.5 +/- 1.1 mm. 8 out of 10 implants were inserted with maximum contact to surrounding bone, two implants were located unfavorably. However, reliable placement of implants in this region is difficult to achieve. The techqni3u described in this paper may be very helpful in the management of patients after maxillary resection without sufficient retention for obturator prostheses.

  2. Clinical retrospective study of self-reported penicillin allergy on dental implant failures and infections.

    Science.gov (United States)

    French, David; Noroozi, Mehdi; Shariati, Batoul; Larjava, Hannu

    2016-01-01

    The aim of this retrospective study was to investigate whether self-reported allergy to penicillin may contribute to a higher rate of postsurgical infection and implant failure. This retrospective, non-interventional, open cohort study reports on implant survival and infection complications of 5,576 implants placed in private practice by one periodontist, and includes 4,132 implants that were followed for at least 1 year. Logistic regression was applied to examine the relationship between self-reported allergy to penicillin and implant survival, while controlling for potential confounders such as smoking, implant site, bone augmentation, loading protocol, immediate implantation, and bone level at baseline. The cumulative survival rate (CSR) was calculated according to the life table method and the Cox proportional hazard model was fitted to data. Out of 5,106 implants placed in patients taking penicillin it was found that 0.8% failed, while 2.1% failed of the 470 implants placed for patients with self-reported allergy to penicillin (P = .002). Odds of failure for implants placed in penicillin-allergic patients were 3.1 times higher than in non-allergic patients. For immediate implant placement, penicillin-allergic patients had a failure rate 10-times higher than the non-allergic cohort. Timing of implant failure occurring within 6 months following implantation was 80% in the penicillin-allergic group versus 54% in the non-allergic group. From the 48 implant sites showing postoperative infection: penicillin-allergic patients had an infection rate of 3.4% (n = 16/470) versus 0.6% in the non-allergic group (n = 32/5,106) (P penicillin allergy was associated with a higher rate of infection, and primarily affected early implant failure.

  3. Short dental implants: an emerging concept in implant treatment.

    Science.gov (United States)

    Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

    2014-06-01

    Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

  4. Do Breast Implants Influence Breastfeeding? A Meta-Analysis of Comparative Studies.

    Science.gov (United States)

    Cheng, Fengrui; Dai, Shuiping; Wang, Chiyi; Zeng, Shaoxue; Chen, Junjie; Cen, Ying

    2018-06-01

    Aesthetic breast implant augmentation surgery is the most popular plastic surgery worldwide. Many women choose to receive breast implants during their reproductive ages, although the long-term effects are still controversial. Research aim: We conducted a meta-analysis to assess the influence of aesthetic breast augmentation on breastfeeding. We also compared the exclusive breastfeeding rates of periareolar versus inframammary incision. A systematic search for comparative studies about breast implants and breastfeeding was performed in PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ScienceDirect, Scopus, and Web of Science through May 2018. Meta-analysis was conducted with a random-effects model (or fixed effects, if heterogeneity was absent). Four cohorts and one cross-sectional study were included. There was a significant reduction in the exclusive breastfeeding rate for women with breast implants compared with women without implants, pooled relative risk = 0.63, 95% confidence interval [0.46, 0.86], as well as the breastfeeding rate, pooled relative risk = 0.88, 95% confidence interval [0.81, 0.95]. There was no evidence that periareolar incision was associated with a reduction in the exclusive breastfeeding rate, pooled relative risk = 0.84, 95% confidence interval [0.45, 1.58]. Participants with breast implants are less likely to establish breastfeeding, especially exclusive breastfeeding. Periareolar incision does not appear to reduce the exclusive breastfeeding rate.

  5. Histology of a dental implant with a platform switched implant-abutment connection

    Directory of Open Access Journals (Sweden)

    Vittoria Perrotti

    2011-10-01

    Full Text Available Background: Peri-implant crestal bone must be stable for aesthetic reasons. Aim of this study was a histologic analysis of an implant with a platform switched implant-abutment connection. Materials and methods: A 32-year-old male patient participated in this study. The patient needed a bilateral mandibular restoration. Four implants were used, and were immediately restored and loaded the same day of insertion. After a 6 weeks healing period, one implant with platform-switched abutment was retrieved with trephine. Before retrieval the implant was osseointegrated and not mobile. On one side of the implant, a 1 mm resorption of the crestal bone was present. On the contrary, on the other side no bone resorption had occurred and about 1 mm of bone was present over the implant shoulder. Results: The bone-implant contact percentage was 65.1 ± 6.3 %. Platform- switching could help in maintaining the height of the peri-implant crestal bone.

  6. Imaging of common breast implants and implant-related complications: A pictorial essay.

    Science.gov (United States)

    Shah, Amisha T; Jankharia, Bijal B

    2016-01-01

    The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

  7. Evaluation of nano-technology-modified zirconia oral implants: a study in rabbits.

    Science.gov (United States)

    Lee, Jaebum; Sieweke, Janet H; Rodriguez, Nancy A; Schüpbach, Peter; Lindström, Håkan; Susin, Cristiano; Wikesjö, Ulf M E

    2009-07-01

    The objective of this study was to screen candidate nano-technology-modified, micro-structured zirconia implant surfaces relative to local bone formation and osseointegration. Proprietary nano-technology surface-modified (calcium phosphate: CaP) micro-structured zirconia implants (A and C), control micro-structured zirconia implants (ZiUnite), and titanium porous oxide implants (TiUnite) were implanted into the femoral condyle in 40 adult male New Zealand White rabbits. Each animal received one implant in each hind leg; thus, 20 animals received A and C implants and 20 animals received ZiUnite and TiUnite implants in contralateral hind legs. Ten animals/group were euthanized at weeks 3 and 6 when biopsies of the implant sites were processed for histometric analysis using digital photomicrographs produced using backscatter scanning electron microscopy. The TiUnite surface demonstrated significantly greater bone-implant contact (BIC) (77.6+/-2.6%) compared with the A (64.6+/-3.6%) and C (62.2+/-3.1%) surfaces at 3 weeks (p0.05). Similarly, there were non-significant differences between the TiUnite and the ZiUnite surfaces (p>0.05). At 6 weeks, there were no significant differences in BIC between the TiUnite (67.1+/-4.2%), ZiUnite (69.7+/-5.7%), A (68.6+/-1.9%), and C (64.5+/-4.1%) surfaces (p>0.05). TiUnite and ZiUnite implant surfaces exhibit high levels of osseointegration that, in this model, confirm their advanced osteoconductive properties. Addition of CaP nano-technology to the ZiUnite surface does not enhance the already advanced osteoconductivity displayed by the TiUnite and ZiUnite implant surfaces.

  8. Monopolar Stimulation of the Implanted Cochlea: A Synthetic Population-Based Study

    DEFF Research Database (Denmark)

    Mangado Lopez, Nerea; Ceresa, Mario; Dejea Velardo, Hector

    2016-01-01

    Cochlear implantation is carried out to recover the sense of hearing. However, its functional outcome varies highly between patients. In the current work, we present a study to assess the functional outcomes of cochlear implants considering the inter-variability found among a population of patien...

  9. Surgical templates for dental implant positioning; current knowledge and clinical perspectives

    Directory of Open Access Journals (Sweden)

    Mohammed Zaheer Kola

    2015-01-01

    Full Text Available Dental implants have been used in a variety of different forms for many years. Since the mid-20 th century, there has been an increase in interest in the implant process for the replacement of missing teeth. Branemark was one of the initial pioneers who applied scientifically based research techniques to develop an endosseous implant that forms an immobile connection with bone. The need for a dental implant to completely address multiple physical and biological factors imposes tremendous constraints on the surgical and handling protocol. Metallic dental implants have been successfully used for decades, but they have serious shortcomings related to their bony union and the fact that their mechanical properties do not match those of bone. However, anatomic limitation and restorative demands encourage the surgeon to gain precision in planning and surgical positioning of dental implants. Ideal placement of the implant facilitates the establishment of favorable forces on the implants and the prosthetic component as well as ensures an aesthetic outcome. Therefore, it is advisable to establish a logical continuity between the planned restoration and the surgical phases, it is essential to use a transfer device that for sure increases the predictability of success. The surgical guide template is fabricated by a dental technician after the presurgical restorative appointments that primarily include determination of occlusal scheme and implant angulations. Here, authors genuinely attempted to review the evolution and clinical applicability of surgical templates used in the placement of dental implants.

  10. Drug Facts

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  13. Characterization of vacancy-type defects induced by the implantation of Se and Si ions into GaAs by a slow positron beam

    International Nuclear Information System (INIS)

    Fujii, Satoshi; Shikata, Shinichi; Wei Long; Tanigawa, Shoichiro.

    1992-01-01

    Variable-energy (0-30keV) positron beam studies have been carried out on 200 keV Se-implanted and 70 keV Si-implanted GaAs specimens before and after annealing for electrical activation. From the measurements of Doppler broadened profiles as a function of incident positron energy, it was found that vacancy clusters with high concentration were introduced in the annealed specimen after Se implantation. From the parallel measurement of electrical characteristics, a higher activation efficiency was found for the higher concentration of vacancy clusters. That fact implies that electrons supplied by the activation of Se also convert the charge state of As vacancies from positive to negative. In contrast, no vacancy clusters were introduced in the Si-implanted GaAs. (author)

  14. Imaging of common breast implants and implant-related complications: A pictorial essay

    Directory of Open Access Journals (Sweden)

    Amisha T Shah

    2016-01-01

    Full Text Available The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

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  1. Partially Biodegradable Distraction Implant to Replace Conventional Implants in Alveolar Bone of Insufficient Height: A Preliminary Study in Dogs.

    Science.gov (United States)

    Li, Tao; Zhang, Yongqiang; Shao, Bo; Gao, Yuan; Zhang, Chen; Cao, Qiang; Kong, Liang

    2015-12-01

    Dental implants have been widely used in the last few decades. However, patients with insufficient bone height need reconstructive surgeries before implant insertion. The distraction implant (DI) has been invented to simplify the treatment procedure, but the shortcomings of DIs have limited their clinical use. We incorporated biodegradable polyester into a novel DI called the partially biodegradable distraction implant (PBDI). The purpose of this study was to assess the radiological, histological, and biomechanical properties of the PBDI in animal models. PBDIs were manufactured and inserted into the atrophied mandibles of nine dogs. Box-shaped alveolar bones were segmented and distracted. The dogs were randomly divided into three groups that were sacrificed 1, 2, and 3 months after the implant insertion. Actual augmentation height (AAH) of the bone segments was measured to evaluate the effect of distraction. X-ray examination and micro-CT reconstruction and analysis were used to evaluate the regenerated bone in the distraction gap and bone around the functional element. Histological sections were used to evaluate the osseointegration and absorption of the PBDI. Fatigue tests were used to evaluate the biomechanical properties of the PBDI. Little change was found in AAH among the three groups. X-ray examination and micro-CT reconstruction showed good growth of regenerated bone in the distraction gap. Alveolar bone volume around the functional element increased steadily. No obvious bone absorption occurred in the alveolar crest around PBDI. Three months after distraction, the functional element achieved osseointegration, and the support element began to be absorbed. All PBDIs survived the fatigue test. The PBDI is a novel and reliable dental implant. It becomes a conventional implant after the absorption of the support element and the removal of the distraction screw. It is a promising replacement for conventional implants in patients with insufficient alveolar bone

  2. Efficacy and safety of a diode laser in second-stage implant surgery: a comparative study.

    Science.gov (United States)

    El-Kholey, K E

    2014-05-01

    For more than a decade, peri-implant tissues have been treated with soft tissue lasers to create a bloodless flap for implant placement and to uncover implants with minimal bleeding, trauma, and anaesthesia. This study was designed to assess if dental implant uncovering is possible with a diode laser without anaesthesia, and to compare its performance with traditional cold scalpel surgery. Thirty patients with a total of 45 completely osseointegrated implants participated in this study. Patients were divided into two groups. For the study group, second-stage implant surgery was done with a 970nm diode laser. For the control group, the implants were exposed with a surgical blade. Certain parameters were used for evaluation of the two techniques. The use of the diode laser obviated the need for local anaesthesia; there was a significant difference between the two groups regarding the need for anaesthesia (Pdiode laser can be used effectively for second-stage implant surgery, providing both the dentist and the patient with additional advantages over the conventional methods used for implant exposure. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  3. Two-stage dental implants inserted in a one-stage procedure : a prospective comparative clinical study

    NARCIS (Netherlands)

    Heijdenrijk, Kees

    2002-01-01

    The results of this study indicate that dental implants designed for a submerged implantation procedure can be used in a single-stage procedure and may be as predictable as one-stage implants. Although one-stage implant systems and two-stage.

  4. The effectiveness of 2-implant overdentures - a pragmatic international multicentre study.

    LENUS (Irish Health Repository)

    Rashid, F

    2011-03-01

    The purpose of this multicentre observational study was to determine patient satisfaction with either conventional dentures or mandibular 2-implant overdentures in a \\'real world\\' setting. Two hundred and three edentulous patients (mean age 68·8 ± 10·4 years) were recruited at eight centres located in North America, South America and Europe. The patients were provided with new mandibular conventional dentures or implant overdentures supported by two implants and ball attachments. At baseline and at 6 months post-treatment, they rated their satisfaction with their mandibular prostheses on 100-mm visual analogue scale questionnaires. One hundred and two (50·2%) participants had valid baseline and 6-month satisfaction data. Although both groups reported improvements, the implant overdenture group reported significantly higher ratings of overall satisfaction, comfort, stability, ability to speak and ability to chew. These results suggest that edentulous patients who choose mandibular implant overdentures have significantly greater improvements in satisfaction, despite their relatively higher cost, than those who choose new conventional dentures.

  5. Hydroxyapatite coating on PEEK implants: Biomechanical and histological study in a rabbit model.

    Science.gov (United States)

    Durham, John W; Montelongo, Sergio A; Ong, Joo L; Guda, Teja; Allen, Matthew J; Rabiei, Afsaneh

    2016-11-01

    A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. A feasibility study of magnetic resonance imaging of silicone breast implants in Finland

    DEFF Research Database (Denmark)

    Kulmala, Ilona; Boice, John D; McLaughlin, Joseph K

    2005-01-01

    to determine the feasibility of conducting a magnetic resonance imaging (MRI)-based study of rupture incidence. The pilot investigation included a clinical examination by a plastic surgeon, MRI scan, and self-administered questionnaire. The participation rate was 100%. Implants in our study represented a cross...... the other diagnosed all implants as intact. The procedures of the feasibility study proved successful, and the results demonstrate the importance of a rigid image evaluation protocol with employment of well-defined rupture criteria, as well as the benefits of several image readers.......Cosmetic breast implants have become increasingly popular throughout the world. However, there is insufficient knowledge about the frequency and severity of local complications such as rupture and capsular contracture. A pilot study of 25 Finnish women with 50 cosmetic breast implants was organized...

  7. Study of the plasma immersion implantation of titanium in stainless steel

    International Nuclear Information System (INIS)

    Nikitenkov, N N; Sutygina, A N; Shulepov, I A; Sivin, D O; Kashkarov, E B

    2015-01-01

    The results of the study of the pulsed plasma-immersion ion implantation of titanium in steel Cr18Ni10Ti depending on the time (dose) implantation are presented. It is shown that the change of the element and the phase composition of the surface layers and their microscopic characteristics and mechanical properties (hardness, wear resistance) depending on the implantation time is not monotonic, but follows to a certain rule. The possibility of interpretation of the obtained results in the thermal spike concept of the generation on the surface by the stable (magic) clusters is discussed. This concept follows logically from the recent studies on the plasma arc composition and from a polyatomic clusters-surface interaction. (paper)

  8. Study of the plasma immersion implantation of titanium in stainless steel

    Science.gov (United States)

    Nikitenkov, N. N.; Sutygina, A. N.; Shulepov, I. A.; Sivin, D. O.; Kashkarov, E. B.

    2015-04-01

    The results of the study of the pulsed plasma-immersion ion implantation of titanium in steel Cr18Ni10Ti depending on the time (dose) implantation are presented. It is shown that the change of the element and the phase composition of the surface layers and their microscopic characteristics and mechanical properties (hardness, wear resistance) depending on the implantation time is not monotonic, but follows to a certain rule. The possibility of interpretation of the obtained results in the thermal spike concept of the generation on the surface by the stable (magic) clusters is discussed. This concept follows logically from the recent studies on the plasma arc composition and from a polyatomic clusters-surface interaction.

  9. Fluorescence lifetime studies of MeV erbium implanted silica glass

    International Nuclear Information System (INIS)

    Lidgard, A.; Polman, A.; Jacobsen, D.C.; Blonder, G.E.; Kistler, R.; Poate, J.M.; Becker, P.C.

    1991-01-01

    MeV erbium ion implantation into various SiO 2 glasses has been studied with the aim of incorporating the rare-earth dopant as an optically active ion in the silica network. The lifetime of the excited state ranges from 1.6 to 12.8 ms, depending on base material and implantation fluence. These results have positive implications for silica-based integrated optical technology. (Author)

  10. Fluorescence lifetime studies of MeV erbium implanted silica glass

    Energy Technology Data Exchange (ETDEWEB)

    Lidgard, A.; Polman, A.; Jacobsen, D.C.; Blonder, G.E.; Kistler, R.; Poate, J.M.; Becker, P.C. (AT and T Bell Labs., Murray Hill, NJ (USA))

    1991-05-23

    MeV erbium ion implantation into various SiO{sub 2} glasses has been studied with the aim of incorporating the rare-earth dopant as an optically active ion in the silica network. The lifetime of the excited state ranges from 1.6 to 12.8 ms, depending on base material and implantation fluence. These results have positive implications for silica-based integrated optical technology. (Author).

  11. Studies of the quality of the intraosseous dental implant bed and of thermal effects in implant pathology

    International Nuclear Information System (INIS)

    Wong, K.

    2000-01-01

    Dental implants may offer solutions to problems of tooth loss and removable dentures, avoiding the blighting of sound teeth in conventional bridgework. However, there may be severe problems due to deficient and poor quality host bone, particularly in the maxillary sinus region. The success of particulate irradiated mineralised cancellous allograft (IMCA) in generating new bone in the sinus was analysed using the trephine bone cores removed to create an implant bed. Bone cores were embedded and examined using 3D fluorescence fight microscopy and scanning electron microscopy in the backscattered electron (BSE) mode to study the quantity and the quality [degree of mineralisation] of bone in implant sites. In all graft cases, new bone as immature (woven) or mature (lamellar) bone formed on the surfaces of the allograft. The bone volume fraction was found to be significantly greater within 5 mm height of the host sinus floor. In an extended study, control sinuses grafted with IMCA soaked in saline showed no significant difference to the test side treated with the patient's own serum. IMCA was shown to retain much of its original topographical and morphological characteristics. Biopsy core specimens from other (non-sinus) sites in both maxilla and mandible were treated similarly. The highest mineral density distributions were observed in the mandible, with the lowest in the residual posterior maxilla beneath the sinus floor. A novel quantitative bone quality scale is proposed to include three parameters of bone quality: mineralisation density, bone volume fraction and connectivity. Clinical use of Laser Doppler Flowmetry (LDF) confirmed positive blood flow in grafts, sinus membrane, and oral tissues. A model of heat conduction in dental implants, predicted oral heat to be a possible factor in implant pathology. The effect of temperature on avian osteoclastic resorption in vitro was studied using a volumetric pit assay. Osteoclastic function measured as volumes and depths

  12. Influence of extracellular matrix coatings on implant stability and osseointegration: an animal study.

    Science.gov (United States)

    Stadlinger, Bernd; Pilling, Eckart; Huhle, Matthias; Mai, Ronald; Bierbaum, Susanne; Bernhardt, Ricardo; Scharnweber, Dieter; Kuhlisch, Eberhard; Hempel, Ute; Eckelt, Uwe

    2007-10-01

    Aim of the present study was to test the hypothesis that the application of components of the extracellular matrix such as glycosaminoglycans used as implant surface coatings in combination with collagen, with and without growth factor, can lead to enhanced ossification and thus improve implant stability compared with collagen coatings alone. Twenty miniature pigs received 120 experimental titanium implants in the mandible. Three types of surface coatings were created: (1) collagen type I (coll), (2) collagen type I/chondroitin sulphate (coll/CS), (3) collagen type I/chondroitin sulphate/BMP-4 (coll/CS/BMP). Periimplant bone formation was assessed within a defined recess along the length axis of the implant. Bone-implant contact (BIC) and bone volume density (BVD) were determined, using both histomorphometry and synchrotron radiation micro computed tomography (SRmicroCT). To measure implant stability, resonance frequency analysis was applied after implantation and 1, 3, 7, and 22 weeks after placement. BIC was highest for coll/CS coated implants, followed by coll, p = 0.082. Histomorphometric BVD did not significantly change for any coating. SRmicroCT analysis showed an increased BVD for collagen coated implants, compared with the other two surface coatings. Implant stability showed a decrease for all coatings up to the third week. At 22 weeks, all coatings showed an increase in stability without reaching their initial level. Highest stability was reached for coll coated implants, p = 0.051. It was concluded that collagen and coll/CS implant coatings have advantageous characteristics for peri-implant bone formation, compared with the further integration of BMP-4.

  13. Effect of unilateral and simultaneous bilateral cochlear implantation on tinnitus : A Prospective Study

    NARCIS (Netherlands)

    van Zon, Alice; Smulders, Yvette E.; Ramakers, Geerte G. J.; Stegeman, Inge; Smit, Adriana L.; Van Zanten, Gijsbert A.; Stokroos, Robert J.; Hendrice, Nadia; Free, Rolien H.; Maat, Bert; Frijns, Johan H. M.; Mylanus, Emmanuel A. M.; Huinck, Wendy J.; Topsakal, Vedat; Tange, Rinze A.; Grolman, Wilko

    Objectives/HypothesisTo determine the effect of cochlear implantation on tinnitus perception in patients with severe bilateral postlingual sensorineural hearing loss and to demonstrate possible differences between unilateral and bilateral cochlear implantation. Study DesignProspective study.

  14. Sub-meninges implantation reduces immune response to neural implants.

    Science.gov (United States)

    Markwardt, Neil T; Stokol, Jodi; Rennaker, Robert L

    2013-04-15

    Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability. Published by Elsevier B.V.

  15. Missing upper incisors: a retrospective study of orthodontic space closure versus implant.

    Science.gov (United States)

    Jamilian, Abdolreza; Perillo, Letizia; Rosa, Marco

    2015-02-25

    The aim of this retrospective study was to compare the esthetic, periodontal, and functional outcomes of orthodontic space closure versus implant substitution in patients with missing maxillary incisors 5 years after completion of treatment. The study group consisted of ten patients treated with orthodontic space closure (six males, four females, mean age 19 ± 2.1 years at the completion of treatment) and ten patients treated with implant insertion (five males, five females, mean age 20 ± 1.4 years at the time of implant insertion). Tooth mobility, plaque index, probing depth, infraocclusion, open gingival embrasure (black triangle), and temporomandibular joint function were recorded at the 5.6 years follow-up. Self-perceived dental esthetic appearance was also evaluated through a visual analog scale (VAS) questionnaire. T-test was used to evaluate the data. All patients were equally satisfied with the appearance of their teeth 5.6 ± 0.4 years after the completion of treatment. No statistically significant differences were found in relation to the VAS scores of the subjects (P Orthodontic space closure and implant of missing maxillary incisors produced similar, well-accepted esthetic results. None of the treatments impaired temporomandibular joint function. Nevertheless, infraocclusion was evident in implant patients. Space closure patients also showed better periodontal health in comparison with implant patients.

  16. Resonance frequency analysis, insertion torque, and bone to implant contact of 4 implant surfaces: comparison and correlation study in sheep.

    Science.gov (United States)

    Dagher, Maroun; Mokbel, Nadim; Jabbour, Gabriel; Naaman, Nada

    2014-12-01

    Primary stability is evaluated using resonance frequency analysis (RFA) and insertion torque (IT). Although there is a strong correlation between RFA and IT, studies failed to find a correlation between RFA and bone to implant contact (BIC) or IT and BIC. To compare RFA, IT, and BIC of SLA, SLActive, Euroteknika, and TiUnite implant surfaces and evaluate the correlation between them. Thirty-two implants were placed in 8 sheep. RFA and IT were recorded. Animals were killed at 1 and 2 months. A significant difference was found in RFA between the 4 surfaces. No significant difference was found for IT. Mean BIC was different between all 4 surfaces. A significant positive correlation was found between RFA and IT with SLA. No significant correlation was found between RFA and BIC and between IT and BIC at 1 and 2 months. Implants with 4 different surfaces have similar IT values but different RFA and BIC. Additionally irrespective of the implant surface, there is no correlation between IT and BIC and between RFA and BIC.

  17. Breast implants and anaplastic large-cell lymphoma: a danish population-based cohort study.

    Science.gov (United States)

    Vase, Maja Ølholm; Friis, Søren; Bautz, Andrea; Bendix, Knud; Sørensen, Henrik Toft; d'Amore, Francesco

    2013-11-01

    A potential link between breast implants and anaplastic large-cell lymphoma (ALCL) has been suggested. We examined lymphoma occurrence in a nationwide cohort of 19,885 Danish women who underwent breast implant surgery during 1973-2010. Standardized incidence ratios (SIR), with 95% confidence intervals (CI), for ALCL and lymphoma overall associated with breast implantation were calculated. During 179,246 person-years of follow-up, we observed 31 cases of lymphoma among cohort members. No cases of ALCL were identified. SIRs for ALCL and lymphoma overall were zero (95% CI, 0-10.3) and 1.20 (95% CI, 0.82-1.70), respectively. In our nationwide cohort study, we did not find an increased risk of lymphoma in general, or ALCL in particular, among Danish women who underwent breast implantation. However, our evaluation of ALCL risk was limited by the rarity of the disease. Our results do not support an association between breast implants and ALCL and are consistent with other studies on cancer risk and breast implants. ©2013 AACR.

  18. Recent advances in dental implants.

    Science.gov (United States)

    Hong, Do Gia Khang; Oh, Ji-Hyeon

    2017-12-01

    Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

  19. Immediate occlusal loading of NanoTite™ tapered implants: a prospective 1-year clinical and radiographic study.

    Science.gov (United States)

    Östman, Pär-Olov; Wennerberg, Ann; Ekestubbe, Annika; Albrektsson, Tomas

    2013-12-01

    During the last decade, high success rates have been reported for implants placed with immediate loading procedures, especially when bone quality and quantity provide good implant stability. In many of these studies, straight-walled implants with moderately rough surfaces were employed. Tapered implants are becoming increasingly more popular due to standardized drilling protocols and reports of high initial primary stability. The aim of the present prospective, single center clinical study was to evaluate surface topographical analysis and the clinical and radiographic outcomes of the NanoTite™ (BIOMET 3i, Palm Beach Gardens, FL, USA) Tapered Implant when used for immediate loading of fixed prostheses and single-tooth restorations. Forty-two patients who needed implant treatment and met admission criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 30 Ncm prior to final seating and an implant stability quotient above 55. A total of 139 NanoTite Tapered implants (112 maxillary and 27 mandibular) were placed by one investigator, and the majority of these implants (n = 77/55%) were placed in posterior regions, and in soft bone (n = 90/65%). A total of 57 prosthetic constructions were evaluated consisting of 20 single-tooth restorations, 30 fixed partial dentures, and 7 complete, fixed maxillary restorations. Radiographs were taken at baseline and at 12 months of follow-up. Of the 139 study implants, one implant failure was declared. The overall cumulative survival rate at 1 year is 99.4%. Mean marginal bone resorption is 1.01 mm (SD 0.85) during the first year of function. Although limited to the short follow-up, immediate loading of NanoTite Tapered implants seems to be a viable option in implant rehabilitation, when insertion torque of at least 30 Ncm is achieved. Further studies are needed to authenticate the finding of this study. © 2012 Wiley

  20. Awareness, knowledge, and attitude of patients toward dental implants - A questionnaire-based prospective study.

    Science.gov (United States)

    Hosadurga, Rajesh; Shanti, Tenneti; Hegde, Shashikanth; Kashyap, Rajesh Shankar; Arunkumar, Suryanarayan Maiya

    2017-01-01

    In developing nations like India awareness and education about dental implants as a treatment modality is still scanty. The study was conducted to determine the awareness, knowledge, and attitude of patients toward dental implants as a treatment modality among the general population and to assess the influence of personality characteristics on accepting dental implants as a treatment modality in general and as well as treatment group. A structured questionnaire-based survey was conducted on 500 randomly selected participants attending the outpatient department. The study was conducted in 2 parts. In the first part of the study, level of awareness, knowledge, and attitude was assessed. In the second part of the study, interactive educational sessions using audiovisual aids were conducted following which a retest was conducted. The participants who agreed to undergo implant treatment were followed up to assess their change in attitude towards dental implants posttreatment. Thus pain, anxiety, functional, and esthetic benefits were measured using visual analog scale. They were further followed up for 1 year to reassess awareness, knowledge, and attitude towards dental implants. A total of 450 individuals completed the questionnaires. Only 106 individuals agreed to participate in the educational sessions and 83 individuals took the retest. Out of these, only 39 individuals chose implants as a treatment option. A significant improvement in the level of information, subjective and objective need for information, was noted after 1 year. In this study, a severe deficit in level of information, subjective and objective need for information towards, dental implants as a treatment modality was noted. In the treatment group, a significant improvement in perception of dental implant as a treatment modality suggests that professionally imparted knowledge can bring about a change in the attitude.

  1. A comparative study on the stress distribution around dental implants in three arch form models for replacing six implants using finite element analysis.

    Science.gov (United States)

    Zarei, Maryam; Jahangirnezhad, Mahmoud; Yousefimanesh, Hojatollah; Robati, Maryam; Robati, Hossein

    2018-01-01

    Dental implant is a method to replacement of missing teeth. It is important for replacing the missed anterior teeth. In vitro method is a safe method for evaluation of stress distribution. Finite element analysis as an in vitro method evaluated stress distribution around replacement of six maxillary anterior teeth implants in three models of maxillary arch. In this in vitro study, using ABAQUS software (Simulia Corporation, Vélizy-Villacoublay, France), implant simulation was performed for reconstruction of six maxillary anterior teeth in three models. Two implants were placed on both sides of the canine tooth region (A model); two implants on both sides of the canine tooth region and another on one side of the central incisor region (B model); and two implants on both sides of the canine tooth region and two implants in the central incisor area (C model). All implants evaluated in three arch forms (tapered, ovoid, and square). Data were analyzed by finite analysis software. Von Mises stress by increasing of implant number was reduced. In a comparison of A model in each maxillary arch, the stress created in the cortical and cancellous bones in the square arch was less than ovoid and tapered arches. The stress created in implants and cortical and cancellous bones in C model was less than A and B models. The C model (four-implant) reduced the stress distribution in cortical and cancellous bones, but this pattern must be evaluated according to arch form and cost benefit of patients.

  2. A longitudinal study of the bilateral benefit in children with bilateral cochlear implants.

    Science.gov (United States)

    Asp, Filip; Mäki-Torkko, Elina; Karltorp, Eva; Harder, Henrik; Hergils, Leif; Eskilsson, Gunnar; Stenfelt, Stefan

    2015-02-01

    To study the development of the bilateral benefit in children using bilateral cochlear implants by measurements of speech recognition and sound localization. Bilateral and unilateral speech recognition in quiet, in multi-source noise, and horizontal sound localization was measured at three occasions during a two-year period, without controlling for age or implant experience. Longitudinal and cross-sectional analyses were performed. Results were compared to cross-sectional data from children with normal hearing. Seventy-eight children aged 5.1-11.9 years, with a mean bilateral cochlear implant experience of 3.3 years and a mean age of 7.8 years, at inclusion in the study. Thirty children with normal hearing aged 4.8-9.0 years provided normative data. For children with cochlear implants, bilateral and unilateral speech recognition in quiet was comparable whereas a bilateral benefit for speech recognition in noise and sound localization was found at all three test occasions. Absolute performance was lower than in children with normal hearing. Early bilateral implantation facilitated sound localization. A bilateral benefit for speech recognition in noise and sound localization continues to exist over time for children with bilateral cochlear implants, but no relative improvement is found after three years of bilateral cochlear implant experience.

  3. Effect of implant number and distribution on load transfer in implant-supported partial fixed dental prostheses for the anterior maxilla: A photoelastic stress analysis study.

    Science.gov (United States)

    Lee, Jae-In; Lee, Yoon; Kim, Yu-Lee; Cho, Hye-Won

    2016-02-01

    The 4-, 3- or even 2-implant-supported partial fixed dental prosthesis (PFDP) designs have been used to rehabilitate the anterior edentulous maxilla. The purpose of this in vitro study was to compare the stress distribution in the supporting tissues surrounding implants placed in the anterior maxilla with 5 PFDP designs. A photoelastic model of the human maxilla with an anterior edentulous region was made with photoelastic resin (PL-2; Vishay Micro-Measurements), and 6 straight implants (OsseoSpeed; Astra Tech AB) were placed in the 6 anterior tooth positions. The 5 design concepts based on implant location were as follows: model 6I: 6 implants; model 2C2CI: 4 implants (2 canines and 2 central incisors); model 2C2LI: 4 implants (2 canines and 2 lateral incisors); model 2C1CI: 3 implants (2 canines and 1 central incisor); and model 2C: 2 canines. A load of 127.4 N was applied on the cingulum of 3 teeth at a 30-degree angle to the long axis of the implant. Stresses that developed in the supporting structure were recorded photographically. The 6-implant-supported PFDP exhibited the most even and lowest distribution of stresses in all loading conditions. When the canine was loaded, the 2- or 3-implant-supported PFDP showed higher stresses around the implant at the canine position than did the 4- or 6-implant-supported PFDP. When the central incisor or lateral incisor was loaded, the two 4-implant-supported PFDPs exhibited similar levels of stresses around the implants and showed lower stresses than did the 2- or 3-implant-supported PFDP. Implant number and distribution influenced stress distribution around the implants in the anterior maxilla. With a decrease in implant number, the stresses around the implants increased. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  4. Salivary bacterial leakage into implant-abutment connections: preliminary results of an in vitro study.

    Science.gov (United States)

    Mencio, F; Papi, P; Di Carlo, S; Pompa, G

    2016-06-01

    The occurrence of bacterial leakage in the internal surface of implants, through implant-abutment interface (IAI), is one of the parameters for analyzing the fabrication quality of the connections. The aim of this in vitro study is to evaluate two different types of implant-abutment connections: the screwed connection (Group 1) and the cemented connection (Group 2), analyzing the permeability of the IAI to bacterial colonization, using human saliva as culture medium. A total of twelve implants were tested, six in each experimental group. Five healthy patients were enrolled in this study. Two milliliters of non-stimulated saliva were collected from each subject and mixed in a test tube. After 14 days of incubation of the bacteria sample in the implant fixtures, a PCR-Real Time analysis was performed. Fisher's exact test was used to compare the proportions of implant-abutment assembled structures detected with bacterial leakage. Differences in the bacterial counts of the two groups were compared using the Mann-Whitney U test. A p value abutment connections compared to the cemented implant-abutment connections. A mean total bacterial count of 1.2E+07 (± 0.25E+07) for Group 1 and of 7.2E+04 (± 14.4E+04) for Group 2 was found, with a high level of significance, p = .0001. Within the limitations of this study it can be concluded that bacterial species from human saliva may penetrate along the implant-abutment interface in both connections, however the cemented connection implants showed the lowest amount of bacterial colonization.

  5. Bacterial microleakage at the abutment-implant interface, in vitro study.

    Science.gov (United States)

    Larrucea, Carlos; Conrado, Aparicio; Olivares, Denise; Padilla, Carlos; Barrera, Andrea; Lobos, Olga

    2018-02-15

    In implant rehabilitation, a microspace is created at the abutment-implant interface (AII). Previous research has shown that oral microbiome can proliferate in this microspace and affect periimplant tissues, causing inflammation in peri-implant tissues. Preventing microbial leakages through the AII is therefore an important goal in implantology. To determine the presence of marginal bacterial microleakage at the AII according to the torque applied to the prosthetic implant in vitro. Twenty-five Ticare Inhex internal conical implants (MG Mozo-Grau, Valladolid, España) were connected to a prosthetic abutment using torques of micro TC, while the rest were mounted on devices according to the bacterial leakage model with Porphyromonas gingivalis. Bacterial leakage was observed only in the implant adjustment as determined by micro-CT. The different torques applied to the abutment-implant system condition the bacterial leakage at the implant interface. No microleakage was observed at 20 and 30 N. © 2018 Wiley Periodicals, Inc.

  6. Study on tribological behaviors of Fe+ ion implanted in 2024 aluminum alloy

    International Nuclear Information System (INIS)

    Zhang Aimin; Chen Jianmin; Shi Weidong; Liu Zhenmin

    2000-01-01

    2024 aluminum alloy was implanted with Fe + ions at a dose of 7x10 16 -3 x 10 17 Fe + /cm 2 . The depth profile of Fe element was investigated by Auger electron spectroscopy (AES). The composition of the surface layer was investigated by XRD with sample-tilting diffraction (STD) mode. The worn out surface was observed by scanning electron microscopy (SEM). Micro-hardness, friction and wear properties have been studied before and after Fe + implantation. An AES analysis shows Fe display Gaussian shape distributions. STD shows Al 5 Fe 2 formed during the implantation. Micro-hardness of surface layer was reduced after implantation, but it did not simply decrease with the increasing implantation doses. The friction and wear tests of implanted and unimplanted samples were carried out on a static-dynamic friction precise measuring apparatus. After implantation, the friction coefficient was reduced from 0.7 to 0.1; the wear resistance was improved remarkably, but decreased with increasing implantation dose. The wear mechanism of the unimplanted sample was adhesive wear, abrasive wear and plastic deformation. The wear reducing effect of Fe + ion induced on 2024 aluminum alloy is mainly attributed to tribooxidation of iron and transfixion of line defect. These two factors prevent the adhesive wear, abrasive wear and plastic deformation of 2024 aluminum alloy

  7. Study of crystal damage by ion implantation using micro RBS/channeling

    International Nuclear Information System (INIS)

    Grambole, D.; Herrmann, F.; Heera, V.; Meijer, J.

    2007-01-01

    The combination of microbeam implantation and in-situ micro RBS/channeling analysis in the Rossendorf nuclear microprobe facility enables crystal damage studies with high current densities not achievable in standard ion implantation experiments. Si(1 0 0) samples were implanted with 600 keV Si + ions and a fluence of 1 x 10 16 cm -2 . Using a beam spot of 200 μm x 200 μm current densities from 4 to 120 μA/cm 2 were obtained. The substrate temperature was varied between RT and 265 deg. C. The implanted regions were subsequently analysed by micro RBS/channeling with a 3 MeV He + beam having a spot size of 50 μm x 50 μm. Crystal damage up to amorphisation was observed in dependence on the substrate temperature. Above a critical temperature T C no amorphisation occurs. T C was determined for each series of samples implanted with the same ion current density j. It was found that the empirical Arrhenius relation j ∼ exp(-E a /kT C ), known from standard implantation experiments, is also valid at high current densities. The observed Arrhenius law can be derived from a model of epitaxial crystallisation stimulated by defect diffusion

  8. Implanted muon studies in condensed matter science

    International Nuclear Information System (INIS)

    Cox, S.F.J.

    1986-12-01

    The paper reviews the broad range of applications of implanted muons in condensed matter. Muon spin rotation is discussed, along with the studies in magnetism, muonion, metals and organic radicals. A description of muon spin relaxation is also given, as well as techniques and applications appropriate to pulsed muon sources. (UK)

  9. The Efficacy of Supportive Peri-Implant Therapies in Preventing Peri-Implantitis and Implant Loss: a Systematic Review of the Literature

    Directory of Open Access Journals (Sweden)

    Ausra Ramanauskaite

    2016-09-01

    Full Text Available Objectives: To study the efficacy of supportive peri-implant therapies in preventing clinical and radiological signs of peri-implantitis and implant loss. Material and Methods: Longitudinal human studies, published between January 1, 2006, and February 1, 2016, were included based on an electronic search using MEDLINE and EMBASE databases and complemented by a manual search. Articles were included only if 1 they comprised a group of patients involved in/adhering to regular supportive peri-implant therapies (SPTs and a control group without such therapies or with poor adherence to them, 2 the protocol of the SPTs was clearly described and 3 the outcome was indicated by means of clinical/radiological changes or implant loss. Results: After initially identifying a total of 710 titles and abstracts, 12 full text articles were selected for eligibility assessment. Seven studies, three prospective and four retrospective, fulfilled the inclusion criteria for this review. The frequency of recall visits varied between the studies from a minimum of one visit every three months to an individually tailored regimen. In all the studies a lack of SPTs or poor adherence to them resulted in significantly higher frequencies of sites with mucosal bleeding, deepened peri-implant pockets or alveolar bone loss. In line with the above, a lack of/poor adherence to SPTs was associated with higher implant loss. Conclusions: To prevent peri-implantitis, an individually tailored supportive programme based on patient motivation and re-instruction in oral hygiene measures combined with professional implant cleaning seem to be crucial.

  10. ESR studies of high-energy phosphorus-ion implanted synthetic diamond crystals

    Energy Technology Data Exchange (ETDEWEB)

    Isoya, J [University of Library and Information Science, Tsukuba, Ibaraki (Japan); Kanda, H; Morita, Y; Ohshima, T

    1997-03-01

    Phosphorus is among potential n-type dopants in diamond. High pressure synthetic diamond crystals of type IIa implanted with high energy (9-18 MeV) phosphorus ions have been studied by using electron spin resonance (ESR) technique. The intensity and the linewidth of the ESR signal attributed to the dangling bond of the amorphous phase varied with the implantation dose, suggesting the nature of the amorphization varies with the dose. The ESR signals of point defects have been observed in the low dose as-implanted crystals and in the high dose crystals annealed at high temperature and at high pressure. (author)

  11. Comparison of two dental implant surface modifications on implants with same macrodesign: an experimental study in the pelvic sheep model.

    Science.gov (United States)

    Ernst, Sabrina; Stübinger, Stefan; Schüpbach, Peter; Sidler, Michéle; Klein, Karina; Ferguson, Stephen J; von Rechenberg, Brigitte

    2015-08-01

    The aim of this study was to compare two different surfaces of one uniform macro-implant design in order to focus exclusively on the osseointegration properties after 2, 4 and 8 weeks and to discuss the animal model chosen. In six mature sheep, n = 36 implants with a highly crystalline and phosphate-enriched anodized titanium oxide surface (TiU) and n = 36 implants with a hydrophilic, sandblasted, large grit and acid-etched surface (SLA) were placed in the pelvic bone. TiU implants were custom-made to match the SLA implant design. The implant stability and bone-to-implant contact (BIC) were assessed by resonance frequency (ISQ), backscatter scanning electron microscopy (B-SEM), light microscopy (LM), micro-CT and intravital fluorochrome staining. Biomechanical removal torque testing was performed. Overall, no statistically significant differences in BIC total (trabecular + cortical) between TiU and SLA were found via LM and B-SEM. BIC values (B-SEM; LM) in both groups revealed a steady rise in trabecular bone attachment to the implant surface after 2, 4 and 8 weeks. In the 2- to 4-week time interval in the TiU group (P = 0.005) as well as in the SLA group (P = 0.01), a statistically significant increase in BIC trabecular could be observed via LM. B-SEM values confirmed the statistically significant increase for TiU (P = 0.001). In both groups, BIC trabecular values after 8 weeks were significantly higher (P ≤ 0.05) than after 2 weeks (B-SEM; LM). Biomechanical data confirmed the histological data. The two surfaces proved comparable osseointegration in this sheep model. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Acceleration of Medpor implant fibrovascularization with local vascular endothelial growth-factor injections: An experimental study

    Directory of Open Access Journals (Sweden)

    Mert Demirel

    2015-12-01

    Full Text Available Objective: Medpor is a biocompatible, high-density porous polyethylene implant that is used for multiple indications in plastic surgery. The most frequent complications associated with the Medpor implant are infection and implant exposure. The primary cause of these complications is poor fibrovascularization of the Medpor implant and poor nourishment of the overlying skin. The present experimental study aimed to determine whether vascular endothelial growth factor (VEGF could accelerate and increase Medpor implant fibrovascularization in vivo, and thereby improve local nourishment and prevent complications. Materials and Methods: The Medpor implant was inserted under the dorsal skin area in 40 Sprague-Dawley rats. 20 rats receiving local VEGF injections comprised the study group. The control group received saline injections. Fibrovascularization of the Medpor implants was compared. Results: In the rats injected with VEGF, the Medpor implant fibrovascularized faster, and there were more newly formed blood vessels, as compared with those in the control group. Conclusion: These findings have led to our use of VEGF-like agents that the accelerate angiogenesis in the Medpor implant as a means to reduce the incidence of such complications as infection and implant exposure. [Arch Clin Exp Surg 2015; 4(4.000: 196-201

  13. Prevalence of Peri-Implant Mucositis and Peri-Implantitis in Patients Treated with a Combination of Axial and Tilted Implants Supporting a Complete Fixed Denture

    Directory of Open Access Journals (Sweden)

    Nicolò Cavalli

    2015-01-01

    Full Text Available Objectives. The aim of this retrospective study was to assess the incidence and prevalence of peri-implant mucositis and peri-implantitis in patients with a fixed full-arch prosthesis supported by two axial and two tilted implants. Materials and Methods. Sixty-nine patients were included in the study. Each patient received a fixed full-arch prosthesis supported by two mesial axial and two distal tilted implants to rehabilitate the upper arch, the lower arch, or both. Three hundred thirty-six implants for 84 restorations were delivered. Patients were scheduled for follow-up visits every 6 months in the first 2 years and yearly after. At each follow-up visit peri-implant mucositis and peri-implantitis were diagnosed if present. Results. The overall follow-up range was from 12 to 130 months (mean 63,2 months. Three patients presented peri-implantitis. The prevalence of peri-implant mucositis ranged between 0 and 7,14% of patients (5,06% of implants while the prevalence of peri-implantitis varied from 0 to 4,55% of patients (3,81% of implants. Conclusions. The prevalence and incidence of peri-implant mucositis and peri-implantitis are lower than most of the studies in literature. Therefore this kind of rehabilitation could be considered a feasible option, on the condition of adopting a systematic hygienic protocol.

  14. Imaging of common breast implants and implant-related complications: A pictorial essay

    OpenAIRE

    Shah, Amisha T; Jankharia, Bijal B

    2016-01-01

    The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance i...

  15. 10-year survival rate and the incidence of peri-implant disease of 374 titanium dental implants with a SLA surface: a prospective cohort study in 177 fully and partially edentulous patients.

    Science.gov (United States)

    van Velzen, Frank J J; Ofec, Ronen; Schulten, Engelbert A J M; Ten Bruggenkate, Christiaan M

    2015-10-01

    This prospective cohort study evaluates the 10-year survival and incidence of peri-implant disease at implant and patient level of sandblasted, large grid, and acid-etched titanium dental implants (Straumann, soft tissue level, SLA surface) in fully and partially edentulous patients. Patients who had dental implant surgery in the period between November 1997 and June 2001, with a follow-up of at least 10 years, were investigated for clinical and radiological examination. Among the 506 inserted dental implants in 250 patients, 10-year data regarding the outcome of implants were available for 374 dental implants in 177 patients. In the current study, peri-implantitis was defined as advanced bone loss (≧1.5 mm. postloading) in combination with bleeding on probing. At 10-year follow-up, only one implant was lost (0.3%) 2 months after implant surgery due to insufficient osseointegration. The average bone loss at 10 year postloading was 0.52 mm. Advanced bone loss at 10-year follow-up was present in 35 dental implants (9.8%). Seven percent of the observed dental implants showed bleeding on probing in combination with advanced bone loss and 4.2% when setting the threshold for advanced bone loss at 2.0 mm. Advanced bone loss without bleeding on probing was present in 2.8% of all implants. In this prospective study, the 10-year survival rate at implant and patient level was 99.7% and 99.4%, respectively. Peri-implantitis was present in 7% of the observed dental implants according to the above-mentioned definition of peri-implantitis. This study shows that SLA implants offer predictable long-term results as support in the treatment of fully and partially edentulous patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Positron annihilation studies of high dose Sb implanted silicon

    International Nuclear Information System (INIS)

    Schut, H.; Eijt, S.W.H.; Beling, C.D.; Ho, K.; Takamura, Y.

    2005-01-01

    The formation and evolution of vacancies and precipitates created by implantation of 60 keV, 2 x 10 16 cm -2 Sb + in pre-amorphized (0 0 1) Cz-Si is studied using the Doppler broadening (DB) and two-dimensional angular correlation of annihilation radiation (2D-ACAR) positron beam techniques. After implantation, samples were laser annealed (LTA) and subsequently thermal annealed at temperatures ranging from 400 to 1000 deg. C. Implantation-induced vacancy-type defects were detected up to a depth of 280 nm. After LTA, positron annihilation related to both Sb and remaining defects is observed in the first 100 nm below the surface. The deeper region only shows positron trapping at vacancy-type defects with strong reduced concentration. Complete removal is obtained after 600 deg. C anneal. At this temperature, the positron data for the upper region reveals trapping at Sb and Si sites only. With increasing annealing time (at 600 deg. C) or increasing temperature (up to 1000 deg. C) positron annihilation at Sb-sites associated with neighboring vacancies becomes apparent. Results are correlated with the observed Sb electrical deactivation above 600 deg. C, the shift from small Sb aggregates to precipitates and out-diffusion of Sb from the implantation region at higher temperatures

  17. Influence of different implant materials on the primary stability of orthodontic mini-implants

    OpenAIRE

    Chin-Yun Pan; Szu-Ting Chou; Yu-Chuan Tseng; Yi-Hsin Yang; Chao-Yi Wu; Ting-Hsun Lan; Pao-Hsin Liu; Hong-Po Chang

    2012-01-01

    This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants w...

  18. Osseointegration of zirconia implants: an SEM observation of the bone-implant interface.

    Science.gov (United States)

    Depprich, Rita; Zipprich, Holger; Ommerborn, Michelle; Mahn, Eduardo; Lammers, Lydia; Handschel, Jörg; Naujoks, Christian; Wiesmann, Hans-Peter; Kübler, Norbert R; Meyer, Ulrich

    2008-11-06

    The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. The present study aimed at investigating the osseointegration of zirconia implants with modified ablative surface at an ultrastructural level. A total of 24 zirconia implants with modified ablative surfaces and 24 titanium implants all of similar shape and surface structure were inserted into the tibia of 12 Göttinger minipigs. Block biopsies were harvested 1 week, 4 weeks or 12 weeks (four animals each) after surgery. Scanning electron microscopy (SEM) analysis was performed at the bone implant interface. Remarkable bone attachment was already seen after 1 week which increased further to intimate bone contact after 4 weeks, observed on both zirconia and titanium implant surfaces. After 12 weeks, osseointegration without interposition of an interfacial layer was detected. At the ultrastructural level, there was no obvious difference between the osseointegration of zirconia implants with modified ablative surfaces and titanium implants with a similar surface topography. The results of this study indicate similar osseointegration of zirconia and titanium implants at the ultrastructural level.

  19. Hydrogen- and helium-implanted silicon: Low-temperature positron-lifetime studies

    DEFF Research Database (Denmark)

    Mäkinen, S.; Rajainmäki, H.; Linderoth, Søren

    1991-01-01

    High-purity single-crystal samples of float-zoned Si have been implanted with 6.95-MeV protons and with 25-MeV 3He2 ions at 15 K, and the positron-lifetime technique has been used to identify the defects created in the samples, and to study the effects of H and He on the annealing of point defects...... in Si. The results have been compared with those of proton-irradiated Si. A 100–300-K annealing stage was clearly observed in hydrogen (H+) -implanted Si, and this stage was almost identical to that in the p-irradiated Si. The final annealing state of the H+-implanted Si started at about 400 K......, and it is connected to annealing out of negatively charged divacancy-oxygen pairs. This stage was clearly longer than that for the p-irradiated Si, probably due to the breakup of Si-H bonds at about 550 K. The 100-K annealing stage was not seen with the He-implanted samples. This has been explained by assuming...

  20. A glass fiber-reinforced composite - bioactive glass cranioplasty implant: A case study of an early development stage implant removed due to a late infection.

    Science.gov (United States)

    Posti, Jussi P; Piitulainen, Jaakko M; Hupa, Leena; Fagerlund, Susanne; Frantzén, Janek; Aitasalo, Kalle M J; Vuorinen, Ville; Serlo, Willy; Syrjänen, Stina; Vallittu, Pekka K

    2015-03-01

    This case study describes the properties of an early development stage bioactive glass containing fiber-reinforced composite calvarial implant with histology that has been in function for two years and three months. The patient is a 33-year old woman with a history of substance abuse, who sustained a severe traumatic brain injury later unsuccessfully treated with an autologous bone flap and a custom-made porous polyethylene implant. She was thereafter treated with developmental stage glass fiber-reinforced composite - bioactive glass implant. After two years and three months, the implant was removed due to an implant site infection. The implant was analyzed histologically, mechanically, and in terms of chemistry and dissolution of bioactive glass. Mechanical integrity of the load bearing fiber-reinforced composite part of the implant was not affected by the in vivo period. Bioactive glass particles demonstrated surface layers of hydroxyapatite like mineral and dissolution, and related increase of pH was considerably less after two and three months period than that for fresh bioactive glass. There was a difference in the histology of the tissues inside the implant areas near to the margin of the implant that absorbed blood during implant installation surgery, showed fibrous tissue with blood vessels, osteoblasts, collagenous fibers with osteoid formation, and tiny clusters of more mature hard tissue. In the center of the implant, where there was less absorbed blood, only fibrous tissue was observed. This finding is in line with the combined positron emission tomography - computed tomography examination with (18F)-fluoride marker, which demonstrated activity of the mineralizing bone by osteoblasts especially at the area near to the margin of the implant 10 months after implantation. Based on these promising reactions found in the bioactive glass containing fiber-reinforced composite implant that has been implanted for two years and three months, calvarial

  1. The Fabulous Fact Fan.

    Science.gov (United States)

    Couch, Jene P.

    1994-01-01

    Discusses the use and construction of "fact fans," fun and easy-to-make manipulatives that provide elementary school students with the opportunity to explore mathematics operations being studied in the classroom and to practice addition, subtraction, multiplication, and division facts. (BB)

  2. Drug Facts

    Medline Plus

    Full Text Available ... form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts ... addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain ...

  3. Drug Facts

    Medline Plus

    Full Text Available ... Facts Search form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, ... Drugs? Effects of Drugs Drug Use and Other People Drug Use and Families Drug Use and Kids ...

  4. Drug Facts

    Medline Plus

    Full Text Available ... Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts Heroin (Smack, Junk) ... treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice ( ...

  5. Study by X-ray diffraction of the crystalline structure versus time of a radioactive implanted coral and of a non radioactive implanted coral

    International Nuclear Information System (INIS)

    Irigaray, J.L.; Oudadesse, H.; Sauvage, T.; El Fadl, H.

    1993-01-01

    The corals used as biomaterials in bone surgery consist of 98% calcium carbonate in the form of aragonite and have orthorhombic crystalline structure. This structure changes progressively into a bone structure in an hexagonal form when the coral is implanted in cortical or spongy surroundings. For this experiment, a radioactive and a non radioactive coral have been implanted in the metaphysics of the ovine femur. The transformation of the orthorhombic structure into the hexagonal bone structure has been studied for the two types of implant. This makes it possible to verify if radioactivity modifies the process of transformation of the implanted biocoral. (K.A.) 3 refs.; 7 figs

  6. Study by X-ray diffraction of the crystalline structure versus time of a radioactive implanted coral and of a non radioactive implanted coral

    Energy Technology Data Exchange (ETDEWEB)

    Irigaray, J.L.; Oudadesse, H.; Sauvage, T.; El Fadl, H. [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire; Lefevre, J.; Barlet, J.P. [Institut National de Recherches Agronomiques, 63 -Saint-Genes-Champanelle (France)

    1993-12-31

    The corals used as biomaterials in bone surgery consist of 98% calcium carbonate in the form of aragonite and have orthorhombic crystalline structure. This structure changes progressively into a bone structure in an hexagonal form when the coral is implanted in cortical or spongy surroundings. For this experiment, a radioactive and a non radioactive coral have been implanted in the metaphysics of the ovine femur. The transformation of the orthorhombic structure into the hexagonal bone structure has been studied for the two types of implant. This makes it possible to verify if radioactivity modifies the process of transformation of the implanted biocoral. (K.A.) 3 refs.; 7 figs.

  7. Drug Facts

    Medline Plus

    Full Text Available ... Pain Medicine (Oxy, Vike) Facts Spice (K2) Facts Tobacco and Nicotine Facts Other Drugs of Abuse What ... Heroin Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine Other Drugs You can call 1-800- ...

  8. Drug Facts

    Medline Plus

    Full Text Available ... Oxy, Vike) Facts Spice (K2) Facts Tobacco and Nicotine Facts Other Drugs of Abuse What is Addiction? ... Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine Other Drugs You can call 1-800-662- ...

  9. 3D accuracy of implant positions in template-guided implant placement as a function of the remaining teeth and the surgical procedure: a retrospective study.

    Science.gov (United States)

    Schnutenhaus, Sigmar; Edelmann, Cornelia; Rudolph, Heike; Dreyhaupt, Jens; Luthardt, Ralph G

    2018-01-22

    The aim of this study was to investigate differences between the virtually planned and clinically achieved implant positions in completely template-guided implantations as a function of the type of edentulous space, the residual natural dentition, and the surgical implementation. Fifty-six patient cases with a total of 122 implants were evaluated retrospectively. The implantations were completely template-based. The data of the planned implant positions were overlaid with the actual clinical implant positions, followed by measurements of the 3D deviations in terms of coronal (x c ) and apical distance, height (x h ), and angulation (ang) and statistical analysis. The mean x c was 1.2 mm (SD 0.7 mm); the mean x a was 1.8 mm (SD 0.9 mm), the mean x h was 0.8 mm (SD 0.7 mm); and the mean ang was 4.8° (SD 3.1). The type of edentulous space and the jaw (maxilla/mandible) had no significant effect on the results in terms of implant positions. The presence of an adjacent natural tooth at the time of implantation had a significant influence on x h (p = 0.04) and ang (p = 0.05). No significant differences were found regarding the surgical approach for any of the parameters examined. The results of our study are in the same range as those of other studies. Template-guided implantation offers a high degree of accuracy even in the presence of different configurations of the residual dentition or different surgical approaches. A clinical benefit is therefore present, especially from a prosthetic point of view. The clinically achievable accuracy can be described as sufficient for further prosthetic treatment, given the intrinsic and methodological tolerances, making prosthetic rehabilitation safe and predictable.

  10. Comparative silicone breast implant evaluation using mammography, sonography, and magnetic resonance imaging: experience with 59 implants.

    Science.gov (United States)

    Ahn, C Y; DeBruhl, N D; Gorczyca, D P; Shaw, W W; Bassett, L W

    1994-10-01

    With the current controversy regarding the safety of silicone implants, the detection and evaluation of implant rupture are causing concern for both plastic surgeons and patients. Our study obtained comparative value analysis of mammography, sonography, and magnetic resonance imaging (MRI) in the detection of silicone implant rupture. Twenty-nine symptomatic patients (total of 59 silicone implants) were entered into the study. Intraoperative findings revealed 21 ruptured implants (36 percent). During physical examination, a positive "squeeze test" was highly suggestive of implant rupture. Mammograms were obtained of 51 implants (sensitivity 11 percent, specificity 89 percent). Sonography was performed on 57 implants (sensitivity 70 percent, specificity 92 percent). MRI was performed on 55 implants (sensitivity 81 percent, specificity 92 percent). Sonographically, implant rupture is demonstrated by the "stepladder sign." Double-lumen implants may appear as false-positive results for rupture on sonography. On MRI, the "linguine sign" represents disrupted fragments of a ruptured implant. The most reliable imaging modality for implant rupture detection is MRI, followed by sonogram. Mammogram is the least reliable. Our study supports the clinical indication and diagnostic value of sonogram and MRI in the evaluation of symptomatic breast implant patients.

  11. The scala vestibuli for cochlear implantation. An anatomic study.

    Science.gov (United States)

    Gulya, A J; Steenerson, R L

    1996-02-01

    Traditionally, cochlear implantation has used the scala tympani (ST) for electrode insertion. When faced with ST ossification, the surgeon may elect to drill out the cochlea to accomplish partial electrode insertion. Theoretically, another option in this situation is to insert the electrode into the scala vestibuli (SV). To determine whether or not the dimensions of the SV are sufficient to accommodate an electrode array so as to assess the feasibility of SV cochlear implantation. The study of 20 normal human temporal bones, comparing the maximum diameter and surface area of the ST with those of the combined SV and scala media. The dimensions of the SV and scala media were comparable to those of the ST and appeared sufficient to accommodate a cochlear implant electrode array. It appears that the combination of SV and scala media is a viable alternative route for electrode insertion, at least on the basis of anatomic dimensions, in those cases in which the ST is obliterated.

  12. The Prosthetic Influence and Biomechanics on Peri-Implant Strain: a Systematic Literature Review of Finite Element Studies

    Directory of Open Access Journals (Sweden)

    Julius Maminskas

    2016-09-01

    Full Text Available Objectives: To systematically review risks of mechanical impact on peri-implant strain and prosthetic influence on stability across finite element studies. Material and Methods: An online literature search was performed on MEDLINE and EMBASE databases published between 2011 and 2016. Following keywords tiered screening and selection of the title, abstract and full-text were performed. Studies of finite element analysis (FEA were considered for inclusion that were written in English and revealed stress concentrations or strain at peri-implant bone level. Results: There were included 20 FEA studies in total. Data were organized according to the following topics: bone layers, type of bone, osseointegration level, bone level, design of implant, diameter and length of implant, implant-abutment connection, type of supra-construction, loading axis, measurement units. The stress or strain at implant-bone contact was measured over all studies and numerical values estimated. Risks of overloading were accented as non-axial loading, misfits, cantilevers and the stability of peri-implant bone was related with the usage of platform switch connection of abutment. Conclusions: Peri-implant area could be affected by non-axial loading, cantilever prosthetic elements, crown/implant ratio, type of implant-abutment connection, misfits, properties of restoration materials and antagonistic tooth. The heterogeneity of finite element analysis studies limits systematization of data. Results of these studies are comparable with other findings of in vitro, in vivo, prospective and retrospective studies.

  13. What do patients expect from treatment with Dental Implants? Perceptions, expectations and misconceptions: a multicenter study.

    Science.gov (United States)

    Yao, Jie; Li, Ming; Tang, Hua; Wang, Peng-Lai; Zhao, Yu-Xiao; McGrath, Colman; Mattheos, Nikos

    2017-03-01

    While research in terms of patient-centered care in implant therapy is growing, few studies have investigated patients' initial perceptions prior to consultation with the implant dentist. The aim of this cross-sectional study was to capture patients' initial information level, perceptions, as well as expectations from the implant therapy. A 34-item questionnaire was developed to investigate patients' preoperative information, perceptions and expectations from treatment with Dental Implants. The study was conducted in three locations (Hong Kong, SiChuan and JiangSu) during 2014-2015 with 277 patients. The main information source about implant therapy was the dentist or hygienist for less than half of the patients (n = 113, 42%). About 62.8% of participants considered that they were in general informed about implants, but only 17.7% felt confident with the information they had. More than 30% of the sample appeared to maintain dangerous misperceptions about Dental Implants: "Dental Implants require less care than natural teeth"; "Treatment with Dental Implants is appropriate for all patients with missing teeth"; "Dental Implants last longer than natural teeth"; and "Treatments with Dental Implants have no risks or complications." Patients were divided when asked whether "Dental Implants are as functional as natural teeth" (agreement frequency = 52.7%). Expectations from treatment outcome were commonly high, while there was a significant correlation between the overall mean of perception scores and outcome expectation scores (r = 0.32, P dental team would need to diagnose and correct prior to initiating implant treatment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Ion-implantation induced defects in ZnO studied by a slow positron beam

    International Nuclear Information System (INIS)

    Chen, Z.Q.; Maekawa, M.; Kawasuso, A.; Sekiguchi, T.; Suzuki, R.

    2004-01-01

    Introduction and annealing behavior of defects in Al + -implanted ZnO have been studied using an energy variable slow positron beam. Vacancy clusters are produced after Al + -implantation. With increasing ion dose above 10 14 Al + /cm 2 the implanted layer is amorphized. Heat treatment up to 600 C enhances the creation of large voids that allow the positronium formation. The large voids disappear accompanying the recrystallization process by further heat treatment above 600 C. Afterwards, implanted Al impurities are completely activated to contribute to the n-type conduction. The ZnO crystal quality is also improved after recrystallization. (orig.)

  15. Osseointegration of subperiosteal implant via guided tissue regeneration. A pilot study

    DEFF Research Database (Denmark)

    Hjørting-Hansen, E; Helbo, M; Aaboe, M

    1995-01-01

    The principle of guided tissue regeneration was applied in an attempt to generate bone to cover a subperiosteal implant. Titanium frame works, casted on individual impressions of the anterior surface of the tibia of 4 Copenhagen White rabbits, were stabilized to the tibia by microscrews, and half...... of them were covered by an expanded polytetrafluoroethylene augmentation membrane. The observation period was 12 weeks. Guided bone regeneration partly covering the implants was seen at all experimental sides; on the control sides the implants were mainly embedded in fibrous tissue. Studies...... are in progress with the aim of reducing marked marrow space formation observed in all the regenerated areas....

  16. Tilted Implants for Full-Arch Rehabilitations in Completely Edentulous Maxilla: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Nicolò Cavalli

    2012-01-01

    Full Text Available Purpose. The aims of this study were to assess the treatment outcome of immediately loaded full-arch fixed bridges anchored to both tilted and axially placed implants in the edentulous maxilla and to evaluate the incidence of biological and prosthetic complications. Materials and Methods. Thirty-four patients (18 women and 16 men were included in the study. Each patient received a maxillary full-arch fixed bridge supported by two axial implants and two distal tilted implants. A total of 136 implants were inserted. Loading was applied within 48 hours of surgery and definitive restorations were placed 4 to 6 months later. Patients were scheduled for followup at 6, 12, 18, and 24 months and annually up to 5 years. At each followup plaque level and bleeding scores were assessed and every complication was recorded. Results. The overall follow-up range was 12 to 73 months (mean 38.8 months. No implant failures were recorded to date, leading to a cumulative implant survival rate of 100%. Biological complications were recorded such as alveolar mucositis (11.8% patients, peri-implantitis (5.9% patients, and temporomandibular joint pain (5.9% patients. The most common prosthetic complications were the fracture or detachment of one or multiple acrylic teeth in both the temporary (20.6% patients and definitive (17.7% patients prosthesis and the minor acrylic fractures in the temporary (14.7% patients and definitive (2.9% patients prosthesis. Hygienic complications occurred in 38.2% patients. No patients’ dissatisfactions were recorded. Conclusions. The high cumulative implant survival rate indicates that this technique could be considered a viable treatment option. An effective recall program is important to early intercept and correct prosthetic and biologic complications in order to avoid implant and prosthetic failures.

  17. A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

    Science.gov (United States)

    Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

    2014-02-01

    Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.

  18. The use of Raman scattering for studying the defects created by implantation in semiconductors

    International Nuclear Information System (INIS)

    Morhange, J.F.; Beserman, R.; Bourgoin, J.

    1974-01-01

    The evolution of Raman scattering with the dose of implanted ions and annealing temperature in silicon and diamond was studied. The variation in the concentration of the defects introduced by implantation, with the dose and annealing temperature were deduced. These results were compared with results obtained using electron paramagnetic resonance. The comparison shows that Raman scattering is a good technique to study the behavior of the defects in ion implanted semiconductors [fr

  19. Effect of implant design and bioactive glass coating on biomechanical properties of fiber-reinforced composite implants.

    Science.gov (United States)

    Ballo, Ahmed M; Akca, Eralp; Ozen, Tuncer; Moritz, Niko; Lassila, Lippo; Vallittu, Pekka; Närhi, Timo

    2014-08-01

    This study aimed to evaluate the influence of implant design and bioactive glass (BAG) coating on the response of bone to fiber-reinforced composite (FRC) implants. Three different FRC implant types were manufactured for the study: non-threaded implants with a BAG coating; threaded implants with a BAG coating; and threaded implants with a grit-blasted surface. Thirty-six implants (six implants for each group per time point) were installed in the tibiae of six pigs. After an implantation period of 4 and 12 wk, the implants were retrieved and prepared for micro-computed tomography (micro-CT), push-out testing, and scanning electron microscopy analysis. Micro-CT demonstrated that the screw-threads and implant structure remained undamaged during the installation. The threaded FRC/BAG implants had the highest bone volume after 12 wk of implantation. The push-out strengths of the threaded FRC/BAG implants after 4 and 12 wk (463°N and 676°N, respectively) were significantly higher than those of the threaded FRC implants (416°N and 549°N, respectively) and the nonthreaded FRC/BAG implants (219°N and 430°N, respectively). Statistically significant correlation was found between bone volume and push-out strength values. This study showed that osseointegrated FRC implants can withstand the static loading up to failure without fracture, and that the addition of BAG significantly improves the push-out strength of FRC implants. © 2014 Eur J Oral Sci.

  20. Poly Implants Prosthèse Breast Implants: A Case Series and Review of the Literature.

    Science.gov (United States)

    Klein, Doron; Hadad, Eran; Wiser, Itay; Wolf, Omer; Itzhaki Shapira, Ortal; Fucks, Shir; Heller, Lior

    2018-01-01

    Silicone breast implants from the French manufacturer Poly Implants Prosthèse (PIP) were recalled from the European market after the French regulator has revealed the implants contain non-medical-grade silicone filler. In December 2011, following a large increase in reported rupture rate and a possible cancer risk, the French Ministry of Health recommended consideration of the PIP explantation, regardless of their condition. In 2012, the Israel Ministry of Health recommended to replace the implants only upon suspected implant rupture. The aims of this study were to characterize breast-augmented Israeli patients with PIP implants, compare their outcomes with those of breast-augmented patients with different implant types, and review the current PIP literature. Breast-augmented patients who underwent an elective breast implant exchange in Israel between January 2011 and January 2017 were included in the study. Data were collected from electronic and physical medical files. There were 73 breast-augmented female patients with 146 PIP breast implants included in this study. Average implant age was 6.7 ± 2.79 years. Mean implant size was 342.8 ± 52.9 mL. Fourteen women (19 implants [16%]) had a high-grade capsular contracture (Baker grade 3-4). During exchange, 28 implants were found to be ruptured (19.2%). Less than 10 years following breast augmentation, PIP implants demonstrated higher rupture rate compared with other implants. Our data are comparable to overall available rupture rate. Among patients with definitive rupture diagnosis, an elective implant removal should be recommended. In cases of undamaged implants, plastic surgeons should also seriously consider PIP implant explantation. When the patient does not desire to remove the implant, an annual physical examination and breast ultrasound are recommended, beginning a year after augmentation.

  1. Experimental studies of N~+ implantation into CVD diamond thin films

    Institute of Scientific and Technical Information of China (English)

    辛火平; 林成鲁; 王建新; 邹世昌; 石晓红; 林梓鑫; 周祖尧; 刘祖刚

    1997-01-01

    The effects of N+ implantation under various conditions on CVD diamond films were analyzed with Raman spectroscopy, four-point probe method, X-ray diffraction (XRD), Rutherford backseattering spectroscopy (RBS), ultraviolet photoluminescence spectroscopy (UV-PL), Fourier transformation infrared absorption spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results show that the N+ implantation doping without any graphitization has been successfully realized when 100 keV N+ ions at a dosage of 2 × 1016 cm-2 were implanted into diamond films at 550℃ . UV-PL spectra indicate that the implanted N+ ions formed an electrically inactive deep-level impurity in diamond films. So the sheet resistance of the sample after N+ implantation changed little. Carbon nitride containing C≡N covalent bond has been successfully synthesized by 100 keV, 1.2×1018 N/cm2 N+ implantation into diamond films. Most of the implanted N+ ions formed C≡N covalent bonds with C atoms. The others were free state nitroge

  2. [Cochlear implant in children: rational, indications and cost/efficacy].

    Science.gov (United States)

    Martini, A; Bovo, R; Trevisi, P; Forli, F; Berrettini, S

    2013-06-01

    this advantage persists in the subsequent years. With regard to cochlear implantation in children older than 12 months the studies show better hearing and linguistic results in children implanted at earlier ages. A sensitive period under 24-36 months has been identified over which cochlear implantation is reported to be less effective in terms of improvement in speech and hearing results. With regard to clinical effectiveness of bilateral cochlear implantation, greater benefits from bilateral implants compared to monolateral ones when assessing hearing in quiet and in noise and in sound localization abilities are reported to be present in both case of simultaneous or sequential bilateral implantation. However, with regard to the delay between the surgeries in sequential bilateral implantation, although benefit is reported to be present even after very long delays, on average long delays between surgeries seems to negatively affect the outcome with the second implant. With regard to benefits after cochlear implantation in children with multiple disabilities, benefits in terms of speech perception and communication as well as in quality of the daily life are reported even if benefits are slower and lower in comparison to those generally attained by implanted children without additional disabilities. Regarding the costs/efficacy ratio, the CI is expensive, in particular because of the cost of the high technological device, long life support, but even if healthcare costs are high, the savings in terms of indirect costs and quality of life are important. The CI, in fact, has a positive impact in terms of quality of life.

  3. Cochlear implants in children implanted in Jordan: A parental overview.

    Science.gov (United States)

    Alkhamra, Rana A

    2015-07-01

    Exploring the perspective of parents on the cochlear implant process in Jordan. Sixty parents of deaf children were surveyed on the information gathering process prior to cochlear implant surgery, and their implant outcome expectations post-surgery. Whether child or parent characteristics may impact parents' post-surgical expectations was explored. Although parents used a variety of information sources when considering a cochlear implant, the ear, nose and throat doctor comprised their major source of information (60%). Parents received a range of information prior to cochlear implant but agreed (93.3%) on the need for a multidisciplinary team approach. Post-surgically, parents' expected major developments in the areas of spoken language (97%), and auditory skills (100%). Receiving education in mainstream schools (92%) was expected too. Parents perceived the cochlear implant decision as the best decision they can make for their child (98.3%). A significant correlation was found between parents contentment with the cochlear implant decision and expecting developments in the area of reading and writing (r=0.7). Child's age at implantation and age at hearing loss diagnosis significantly affected parents' post-implant outcome expectations (pparents agree on the need for a comprehensive multidisciplinary team approach during the different stages of the cochlear implant process. Parents' education about cochlear implants prior to the surgery can affect their post-surgical outcome expectations. The parental perspective presented in this study can help professionals develop better understanding of parents' needs and expectations and henceforth improve their services and support during the different stages of the cochlear implant process. Copyright © 2015. Published by Elsevier Ireland Ltd.

  4. Precision of fit between implant impression coping and implant replica pairs for three implant systems.

    Science.gov (United States)

    Nicoll, Roxanna J; Sun, Albert; Haney, Stephan; Turkyilmaz, Ilser

    2013-01-01

    The fabrication of an accurately fitting implant-supported fixed prosthesis requires multiple steps, the first of which is assembling the impression coping on the implant. An imprecise fit of the impression coping on the implant will cause errors that will be magnified in subsequent steps of prosthesis fabrication. The purpose of this study was to characterize the 3-dimensional (3D) precision of fit between impression coping and implant replica pairs for 3 implant systems. The selected implant systems represent the 3 main joint types used in implant dentistry: external hexagonal, internal trilobe, and internal conical. Ten impression copings and 10 implant replicas from each of the 3 systems, B (Brånemark System), R (NobelReplace Select), and A (NobelActive) were paired. A standardized aluminum test body was luted to each impression coping, and the corresponding implant replica was embedded in a stone base. A coordinate measuring machine was used to quantify the maximum range of displacement in a vertical direction as a function of the tightening force applied to the guide pin. Maximum angular displacement in a horizontal plane was measured as a function of manual clockwise or counterclockwise rotation. Vertical and rotational positioning was analyzed by using 1-way analysis of variance (ANOVA). The Fisher protected least significant difference (PLSD) multiple comparisons test of the means was applied when the F-test in the ANOVA was significant (α=.05). The mean and standard deviation for change in the vertical positioning of impression copings was 4.3 ±2.1 μm for implant system B, 2.8 ±4.2 μm for implant system R, and 20.6 ±8.8 μm for implant system A. The mean and standard deviation for rotational positioning was 3.21 ±0.98 degrees for system B, 2.58 ±1.03 degrees for system R, and 5.30 ±0.79 degrees for system A. The P-value for vertical positioning between groups A and B and between groups A and R was <.001. No significant differences were found for

  5. Understanding long-term silver release from surface modified porous titanium implants.

    Science.gov (United States)

    Shivaram, Anish; Bose, Susmita; Bandyopadhyay, Amit

    2017-08-01

    Prevention of orthopedic device related infection (ODRI) using antibiotics has met with limited amount of success and is still a big concern during post-surgery. As an alternative, use of silver as an antibiotic treatment to prevent surgical infections is being used due to the well-established antimicrobial properties of silver. However, in most cases silver is used in particulate form with wound dressings or with short-term devices such as catheters but not with load-bearing implants. We hypothesize that strongly adherent silver to load-bearing implants can offer longer term solution to infection in vivo. Keeping that in mind, the focus of this study was to understand the long term release study of silver ions for a period of minimum 6months from silver coated surface modified porous titanium implants. Implants were fabricated using a LENS™ system, a powder based additive manufacturing technique, with at least 25% volume porosity, with and without TiO 2 nanotubes in phosphate buffer saline (pH 7.4) to see if the total release of silver ions is within the toxic limit for human cells. Considering the fact that infection sites may reduce the local pH, silver release was also studied in acetate buffer (pH 5.0) for a period of 4weeks. Along with that, the osseointegrative properties as well as cytotoxicity of porous titanium implants were assessed in vivo for a period of 12weeks using a rat distal femur model. In vivo results indicate that porous titanium implants with silver coating show comparable, if not better, biocompatibility and bonding at the bone-implant interface negating any concerns related to toxicity related to silver to normal cells. The current research is based on our recently patented technology, however focused on understanding longer-term silver release to mitigate infection related problems in load-bearing implants that can even arise several months after the surgery. Prevention of orthopedic device related infection using antibiotics has met

  6. A new system of implant abutment connection: how to improve a two piece implant system sealing.

    Science.gov (United States)

    Grecchi, F; DI Girolamo, M; Cura, F; Candotto, V; Carinci, F

    2017-01-01

    Implant dentistry has become one of the most successful dentistry techniques for replacing missing teeth. The success rate of implant dentistry is above 80%. However, peri-implantitis is a later complication of implant dentistry that if untreated, can lead to implant loss. One of the hypotized causes of peri-implantis is the bacterial leakage at the level of implant-abutment connection. Bacterial leakage is favored to the presence of a micro gap at the implant-abutment interface, allowing microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 9%. The reported results are better to those of previous studies carried out on different implant systems. Until now, none implant-abutment system has been proven to seal the gap between implant and abutment.

  7. Optical studies of cobalt implanted rutile TiO2 (110) surfaces

    International Nuclear Information System (INIS)

    Joshi, Shalik Ram; Padmanabhan, B.; Chanda, Anupama; Mishra, Indrani; Malik, V.K.; Mishra, N.C.; Kanjilal, D.; Varma, Shikha

    2016-01-01

    Highlights: • The present study displays formation of nanostructures after Co implantation on TiO 2 surfaces. • Preferential sputtering leads to the creation of oxygen vacancies on the surface. • A large enhancement in visible light absorbance (nearly 5 times compared to pristine) is observed. • Creation of self-organized nanostructures and Ti 3+ oxygen vacancies promote photoabsorption. • Formation of Co-nanoclusters and Co–Ti–O phase play concerted role in enhancing photo-absorption. - Abstract: Present study investigates the photoabsorption properties of single crystal rutile TiO 2 (110) surfaces after they have been implanted with low fluences of cobalt ions. The surfaces, after implantation, demonstrate fabrication of nanostructures and anisotropic nano-ripple patterns. Creation of oxygen vacancies (Ti 3+ states), development of cobalt nano-clusters as well as band gap modifications have also been observed. Results presented here demonstrate that fabrication of self organized nanostructures, upon implantation, along with the development of oxygen vacancies and ligand field transitions of cobalt ion promote the enhancement of photo-absorbance in both UV (∼2 times) and visible (∼5 times) regimes. These investigations on nanostructured TiO 2 surfaces can be important for photo-catalysis.

  8. Impact of an implantable steroid contraceptive (etonogestrel-releasing implant) on quality of life and sexual function: a preliminary study.

    Science.gov (United States)

    Di Carlo, Costantino; Sansone, Anna; De Rosa, Nicoletta; Gargano, Virginia; Tommaselli, Giovanni Antonio; Nappi, Carmine; Bifulco, Giuseppe

    2014-01-01

    The aim of the study was to determine the impact of etonogestrel (ENG)-implant used for contraceptive purpose on Quality of life (QoL) and on sexual function (FSF) of healthy Italian women. The Female Sexual Function Index (FSFI) questionnaire and the Short Form-36 (SF-36) validated questionnaire were administered at baseline, 3 and 6 months after insertion of Nexplanon. The implant seems to have a positive impact on QoL after the first three months of therapy. Users showed an improved general health status and physical role status. The implant did not show negative effects on libido and on sexual function. In the first three months of treatment, users experienced a temporary reduction of vitality, mental health, social functioning and emotional role functioning, which seem to disappear after six months of therapy.

  9. Implants delivering bisphosphonate locally increase periprosthetic bone density in an osteoporotic sheep model. A pilot study

    Directory of Open Access Journals (Sweden)

    GVA Stadelmann

    2008-07-01

    Full Text Available It is a clinical challenge to obtain a sufficient orthopaedic implant fixation in weak osteoporotic bone. When the primary implant fixation is poor, micromotions occur at the bone-implant interface, activating osteoclasts, which leads to implant loosening. Bisphosphonate can be used to prevent the osteoclastic response, but when administered systemically its bioavailability is low and the time it takes for the drug to reach the periprosthetic bone may be a limiting factor. Recent data has shown that delivering bisphosphonate locally from the implant surface could be an interesting solution. Local bisphosphonate delivery increased periprosthetic bone density, which leads to a stronger implant fixation, as demonstrated in rats by the increased implant pullout force. The aim of the present study was to verify the positive effect on periprosthetic bone remodelling of local bisphosphonate delivery in an osteoporotic sheep model. Four implants coated with zoledronate and two control implants were inserted in the femoral condyle of ovariectomized sheep for 4 weeks. The bone at the implant surface was 50% higher in the zoledronate-group compared to control group. This effect was significant up to a distance of 400µm from the implant surface. The presented results are similar to what was observed in the osteoporotic rat model, which suggest that the concept of releasing zoledronate locally from the implant to increase the implant fixation is not species specific. The results of this trial study support the claim that local zoledronate could increase the fixation of an implant in weak bone.

  10. Study by nuclear techniques of the impurity-defect interaction in implanted metals

    International Nuclear Information System (INIS)

    Thome, Lionel.

    1978-01-01

    The properties of out equilibrium alloys formed by impurity implantation are strongly influenced by radiation damage created during implantation. This work presents a study, via hyperfine interaction and lattice location experiments, of the impurity-defect interaction in ion implanted metals. When the impurity and defect concentrations in the implanted layer are small, i.e. when impurities are uniformly recoil implanted in the whole crystal volume following a nuclear reaction (Aq In experiments), the impurity interacts with its own damage cascade. In this case, a vacancy is found to be trapped by a fraction of impurities during an athermal process. The value of this fraction does not seem to depend critically on impurity and host. When the impurity and defect concentrations are such that defect cascades interact, i.e. when impurities are implanted with an isotope separator (Fe Yb experiments), the observed impurity-vacancy (or vacancy cluster) interactions depend then strongly on the nature of impurity and host. An empirical relation, which indicates the importance of elastic effects, has been found between the proportion of impurities interacting with defects and the difference between impurity and host atom radii. At implantation temperature such that vacancies are mobile, the impurity-defect interaction depends essentially on vacancy migration. A model based on chemical kinetics has been developed to account for the variation with temperature of measured quantities [fr

  11. Maxillary Overdentures Supported by Four Splinted Direct Metal Laser Sintering Implants: A 3-Year Prospective Clinical Study

    Directory of Open Access Journals (Sweden)

    Francesco Mangano

    2014-01-01

    Full Text Available Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females to support bar-retained maxillary overdentures (ODs. Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB. Results. The 3-year implant survival rate was 97.4% (implant-based and 92.9% (patient-based. Three implants failed. The incidence of biological complication was 3.5% (implant-based and 7.1% (patient-based. The incidence of prosthetic complication was 17.8% (patient-based. No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results.

  12. Maxillary overdentures supported by four splinted direct metal laser sintering implants: a 3-year prospective clinical study.

    Science.gov (United States)

    Mangano, Francesco; Luongo, Fabrizia; Shibli, Jamil Awad; Anil, Sukumaran; Mangano, Carlo

    2014-01-01

    Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS) technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females) to support bar-retained maxillary overdentures (ODs). Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB). Results. The 3-year implant survival rate was 97.4% (implant-based) and 92.9% (patient-based). Three implants failed. The incidence of biological complication was 3.5% (implant-based) and 7.1% (patient-based). The incidence of prosthetic complication was 17.8% (patient-based). No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results.

  13. Immediate occlusal loading of NanoTite PREVAIL implants: a prospective 1-year clinical and radiographic study.

    Science.gov (United States)

    Ostman, Pär-Olov; Wennerberg, Ann; Albrektsson, Tomas

    2010-03-01

    Recently, a new implant surface texture, featuring application of nanometer-scale calcium phosphate has been shown to enhance early bone fixation and formation in preclinical studies and in human histomorphometric studies, which may be beneficial in immediate loading situations. The purpose of the present prospective clinical study was to, during 1 year, clinically and radiographically evaluate a nanometer scale surface modified implant placed for immediate loading of fixed prostheses in both maxillary and mandibular regions. Thirty-five out of 38 patients who needed implant treatment and met inclusion criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 25 Ncm prior to final seating and an implant stability quotient above 55. A total of 102 NanoTite PREVAIL (NTP) implants (BIOMET 3i, Palm Beach Gardens, FL, USA) (66 maxillary and 36 mandibular) were placed by one investigator, and the majority of these were placed in posterior regions (65%) and in soft bone (69%). A total of 44 prosthetic constructions were evaluated consisting of 14 single-tooth restorations, 26 fixed partial dentures, and four complete fixed restorations. All provisional constructions were delivered within 1 hour, and the final constructions placed after 4 months. Implants were monitored for clinical and radiographic outcomes at follow-up examinations scheduled for 3, 6, and 12 months. Of the 102 study implants, one implant failed. The simple cumulative survival rate value at 1 year was 99.2%. The average marginal bone resorption was 0.37 mm (SD 0.39) during the first year in function. According to the success criteria of Albrektsson and Zarb, success grade 1 was found with 93% of the implants. Although limited to the short follow-up, immediate loading of NanoTite Prevail implants seems to be a viable option in implant rehabilitation, at least when a good initial fixation is achieved.

  14. Prevention of Cutaneous Tissue Contracture During Removal of Craniofacial Implant Superstructures for CT and MRI Studies

    Directory of Open Access Journals (Sweden)

    Maureen Sullivan

    2010-04-01

    Full Text Available Objectives: Head and neck cancer patients who have lost facial parts following surgical intervention frequently require craniofacial implant retained facial prostheses for restoration. Many craniofacial implant patients require computed tomography and magnetic resonance imaging scans as part of their long-term follow-up care. Consequently removal of implant superstructures and peri-abutment tissue management is required for those studies. The purpose of the present paper was to describe a method for eliminating cranial imaging artifacts in patients with craniofacial implants.Material and Methods: Three patients wearing extraoral implant retained facial prostheses needing either computed tomography or magnetic resonance imaging studies were discussed. Peri-implant soft tissues contracture after removal of percutaneous craniofacial implant abutments during computed tomography and magnetic resonance imaging studies was prevented using a method proposed by authors. The procedure involves temporary removal of the supra-implant components prior to imaging and filling of the tissue openings with polyvinyl siloxane dental impression material.Results: Immediately after filling of the tissue openings with polyvinyl siloxane dental impression material patients were sent for the imaging studies, and were asked to return for removal of the silicone plugs and reconnection of all superstructure hardware after imaging procedures were complete. The silicone plugs were easily removed with a dental explorer. The percutaneous abutments were immediately replaced and screwed into the implants which were at the bone level.Conclusions: Presented herein method eliminates the source of artifacts and prevents contracture of percutaneous tissues upon removal of the implant abutments during imaging.

  15. Study of wettability and cell viability of H implanted stainless steel

    Science.gov (United States)

    Shafique, Muhammad Ahsan; Ahmad, Riaz; Rehman, Ihtesham Ur

    2018-03-01

    In the present work, the effect of hydrogen ion implantation on surface wettability and biocompatibility of stainless steel is investigated. Hydrogen ions are implanted in the near-surface of stainless steel to facilitate hydrogen bonding at different doses with constant energy of 500 KeV, which consequently improve the surface wettability. Treated and untreated sample are characterized for surface wettability, incubation of hydroxyapatite and cell viability. Contact angle (CA) study reveals that surface wettability increases with increasing H-ion dose. Raman spectroscopy shows that precipitation of hydroxyapatite over the surface increase with increasing dose of H-ions. Cell viability study using MTT assay describes improved cell viability in treated samples as compared to the untreated sample. It is found that low dose of H-ions is more effective for cell proliferation and the cell count decreases with increasing ion dose. Our study demonstrates that H ion implantation improves the surface wettability and biocompatibility of stainless steel.

  16. TEM study of amorphous alloys produced by ion implantation

    International Nuclear Information System (INIS)

    Johnson, E.; Grant, W.A.; Wohlenberg, P.; Hansen, P.; Chadderton, L.T.

    1978-01-01

    Ion implantation is a technique for introducing foreign elements into surface layers of solids. Ions, as a suitably accelerated beam, penetrate the surface, slow down by collisions with target atoms to produce a doped layer. This non-equilibrium technique can provide a wide range of alloys without the restrictions imposed by equilibrium phase diagrams. This paper reports on the production of some amorphous transition metal-metalloid alloys by implantation. Thinned foils of Ni, Fe and stainless steel were implanted at room temperature with Dy + and P + ions at doses between 10 13 - 10 17 ions/cm 2 at energies of 20 and 40 keV respectively. Transmission electron microscopy and selected area diffraction analysis were used to investigate the implanted specimens. Radial diffracted intensity measurements confirmed the presence of an amorphous implanted layer. The peak positions of the maxima are in good agreement with data for similar alloys produced by conventional techniques. Only certain ion/target combinations produce these amorphous layers. Implantations at doses lower than those needed for amorphization often result in formation of new crystalline phases such as an h.c.p. phase in nickel and a b.c.c. phase in stainless steel. (Auth.)

  17. Cochlear implantation in late-implanted adults with prelingual deafness.

    Science.gov (United States)

    Most, Tova; Shrem, Hadas; Duvdevani, Ilana

    2010-01-01

    The purpose of this study was to examine the effect of cochlear implantation (CI) on prelingually deafened participants who were implanted as adults. The effect of the CI was examined with regard to the following variables: communication, family, social skills, education, and work satisfaction with one's life, loneliness, and self-esteem. Thirty-eight adults participated. Four self-report questionnaires were used at 2 points in time: before and after CI. The research findings show significant differences in the reports of most variables before and after implantation. The participants felt better with regard to communication, social skills, education, and work and satisfaction with one's life after implantation in comparison to their feelings before implantation. Furthermore, they felt less lonely after implantation. However, there were no significant differences before and after implantation regarding their feelings within the family and regarding their self-esteem. The results demonstrated the need to evaluate the benefits resulting from the CI not only with traditional clinical measures but with additional measures as well. Furthermore, they demonstrated the benefit of the CI on the positive psychosociological implications of prelingually deafened adults. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Management of peri-implant infections

    Directory of Open Access Journals (Sweden)

    K L Vandana

    2015-01-01

    Full Text Available The ever-increasing popularity of dental implants in recent years has been associated with the reported incidence of short-term and long-term complications such as peri-implant mucositis and peri-implantitis. Therapies proposed for treating peri-implantitis are based on the evidence available for the treatment of periodontitis, and are aimed at reducing the bacterial load within peri-implant pockets and decontaminating implant surfaces, and, in some cases, attempting afterward to bring about bone regeneration. The treatment of peri-implant infections comprises conservative (nonsurgical and surgical approaches. This paper reviews various treatment strategies used for the treatment of peri-implant diseases. There are many approaches suggested by various authors for the treatment of peri-implant diseases, but there is no “ideal peri-implant therapy” that has been described in the literature. There is no consensus regarding the treatment protocol as the studies conducted so far have had varying study designs, small sample sizes, and short follow-up periods.

  19. Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection: a Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

    2017-01-01

    The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied. The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone loss around implants with a scalloped implant-abutment connection. A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must be rejected. However, further long-term randomized controlled trials assessing implant treatment outcome with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of implants with a scalloped implant-abutment connection on preservation of the peri-implant marginal bone level.

  20. Histomorphometric and removal torque analysis for TiO2-blasted titanium implants. An experimental study on dogs

    DEFF Research Database (Denmark)

    Gotfredsen, K; Nimb, L; Hjörting-Hansen, E

    1992-01-01

    The aim of the present study was to compare the anchorage of TiO2-blasted screw and cylindrical implants with conventionally used machine-produced screw and cylindrical implants inserted immediately in extraction sockets on dogs. 6 adult mongrel dogs had 3rd and 4th mandibular premolars extracted...... bilaterally and 24 commercial pure titanium implants were placed immediately in extraction sockets and covered with mucoperiosteum. Each dog had inserted 4 implants: 1 screw implant and 1 cylindrical implant blasted with titanium-dioxide-particles; 1 screw implant and 1 cylindrical implant with machine...

  1. Breast implants and breast cancer: a review of incidence, detection, mortality, and survival.

    Science.gov (United States)

    Deapen, Dennis

    2007-12-01

    Soon after breast implants were commercially introduced over 30 years ago, questions about potential carcinogenicity were raised. Animal experiments dating back to the mid-twentieth century demonstrated that foreign body implantation of many materials, including silicone, can induce sarcomas. Indeed, female breast cancer incidence rates in the United States have increased substantially over that period. Of the several published studies from various countries that have formally investigated the risk of breast cancer among augmentation mammaplasty patients, none show any evidence of increased risk. In fact, most find lower than expected risk, some with statistically significant reductions. Similarly, breast cancer mortality among these patients is generally found to be below that expected of other similar women. Delayed detection of breast cancer is a concern for these patients because implants can interfere with mammography. However, using indicators such as stage at diagnosis and tumor size, current research shows that augmentation patients do not experience delayed detection. Furthermore, several comparisons of post-breast cancer survival of augmented versus nonaugmented patients have found no significant differences. In summary, breast implants are not associated with an increased risk of breast cancer incidence or death, and these patients do not experience delayed detection or poorer post-breast cancer survival.

  2. Ion-implantation induced defects in ZnO studied by a slow positron beam

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.Q.; Maekawa, M.; Kawasuso, A. [Japan Atomic Energy Research Institute, Gunma (Japan); Sekiguchi, T. [National Inst. for Materials Science, Tsukuba, Ibaraki (Japan); Suzuki, R. [National Inst. of Advanced Industrial Science and Technology, Tsukuba, Ibaraki (Japan)

    2004-07-01

    Introduction and annealing behavior of defects in Al{sup +}-implanted ZnO have been studied using an energy variable slow positron beam. Vacancy clusters are produced after Al{sup +}-implantation. With increasing ion dose above 10{sup 14} Al{sup +}/cm{sup 2} the implanted layer is amorphized. Heat treatment up to 600 C enhances the creation of large voids that allow the positronium formation. The large voids disappear accompanying the recrystallization process by further heat treatment above 600 C. Afterwards, implanted Al impurities are completely activated to contribute to the n-type conduction. The ZnO crystal quality is also improved after recrystallization. (orig.)

  3. Implant Materials Generate Different Peri-implant Inflammatory Factors

    OpenAIRE

    Olivares-Navarrete, Rene; Hyzy, Sharon L.; Slosar, Paul J.; Schneider, Jennifer M.; Schwartz, Zvi; Boyan, Barbara D.

    2015-01-01

    Study Design. An in vitro study examining factors produced by human mesenchymal stem cells on spine implant materials. Objective. The aim of this study was to examine whether the inflammatory microenvironment generated by cells on titanium-aluminum-vanadium (Ti-alloy, TiAlV) surfaces is affected by surface microtexture and whether it differs from that generated on poly-ether-ether-ketone (PEEK). Summary of Background Data. Histologically, implants fabricated from PEEK have a fibrous connectiv...

  4. Ellipsometric and channeling studies on ion-implanted silicon

    International Nuclear Information System (INIS)

    Lohner, T.; Mezey, G.; Kotai, E.; Paszti, F.; Kiralyhidi, L.; Valyi, G.; Gyulai, J.

    1980-09-01

    RBS and ellipsometric investigations were combined to separate the contribution of radiation damage and overlayer contamination. It is pointed out that disorder effects which were produced by silicon self-implantation are shielded without proper surface cleaning. For cleaning, plasma stripping proved to be an effective method. The change in psi parameter could be correlated with the degree of amorphousness. It seems that Δ parameter ''feels'' crystalline-amorphous phase transition on low dose 31 P + and 27 Al + implants. No clear evidence was found for impurity effects on high-dose 75 As + and 31 P + implants. (author)

  5. Magnesium plasma immersion ion implantation in a large straight magnetic duct

    International Nuclear Information System (INIS)

    Tan, Ing Hwie; Ueda, Mario; Dallaqua, Renato S; Rossi, Jose O; Beloto, Antonio F; Abramof, Eduardo; Inoue, Y; Takai, Osamu

    2002-01-01

    Magnesium ions were implanted on silicon wafers using a vacuum arc plasma system with a straight 1 m long magnetic duct, 0.22 m in diameter. Good macroparticle filtering was obtained in samples positioned facing the plasma stream and complete filtering was achieved in samples with surfaces parallel to the plasma stream and magnetic field. Deposition is also minimized by placing sample surfaces parallel to the plasma stream. High resolution x-ray diffraction rocking curves of implanted samples show that the changes in lattice constant are due to compressive strain, and the distortion is larger for higher voltages. Without magnetic field the implantation was a few hundred angstroms deep, as expected, but with magnetic field the depth profile was surprisingly extended to over 0.1 μm, a fact for which we do not yet have a convincing explanation, but could be related to radiation enhanced segregation. The presence of a magnetic field increases substantially the retained implantation dose due to the increase in plasma density by two orders of magnitude

  6. Maxillary Four Implant-retained Overdentures via Locator® Attachment: Intermediate-term Results from a Retrospective Study.

    Science.gov (United States)

    Wang, Feng; Monje, Alberto; Huang, Wei; Zhang, Zhiyong; Wang, Guomin; Wu, Yiqun

    2016-06-01

    Maxillary overdentures have been utilized to restore oral function in scenarios where limited bone structure represents a drawback for financial issues and for cases where oral hygiene is uncertain. The aim of this study was to evaluate the intermediate-term clinical outcome of four locator attachment retaining maxillary overdentures and to test their reliability. A retrospective study was conducted from January 2007 to October 2013. After the placement of four maxillary dental implants and a healing period of approximately 3 months, all the implants were restored with locator-retained overdentures with partial palatal coverage. Subjects and implant characteristics, implant position (anterior vs posterior maxilla), bone quality, and opposing dentition were recorded. Peri-implant clinical parameters and marginal bone loss (MBL) were evaluated after delivery of the final prosthesis and annually thereafter. The performance of locator components and the prosthetic restoration were also recorded at follow-up. A total of 104 implants were placed in 26 subjects (11 women, 15 men; mean age, 64 years; age range, 55-76 years). One implant failed before loading. One subject dropped out of the study during a mean follow-up period of 46 months (range: 7-73 months), achieving an overall survival rate of 95.2%. Clinical parameters revealed healthy tissues around most of the implants, with low scores of plaque and bleeding indices. At the last follow-up evaluation, the mean MBL was 1.7 ± 1.1 mm (0.4-2.6 mm). Regression model analysis indicated that MBL for implants in the posterior maxilla was significantly higher than that for implants in the anterior maxilla (p = .0487). Overall, 26 technical and prosthetic complications were reported. Within the limitations of this study, maxillary four implant-retained overdentures via Locator attachment seem to be a predictable alternative for oral rehabilitation. © 2015 Wiley Periodicals, Inc.

  7. Implant-supported removable partial dentures in the mandible: A 3-16 year retrospective study.

    Science.gov (United States)

    Jensen, Charlotte; Meijer, Henny J A; Raghoebar, Gerry M; Kerdijk, Wouter; Cune, Marco S

    2017-04-01

    The purpose of this retrospective study was to assess performance, together with biological and technical complications, of implant-supported removable partial dentures (ISRPD) in mandibular Kennedy class I situations with implants placed in the anterior or posterior position. 23 subjects with two endosseous implants to support a bilateral-free-ending mandibular removable denture were examined. Eight subjects had implants in the premolar (anterior) region and 15 subjects implants in the molar (posterior) region. Biological and technical complications were recorded from the patients' medical record. Patients filled out a validated questionnaire regarding their appreciation of oral health related quality of life (OHIP-NL49) and a VAS score on overall satisfaction. Over a mean follow-up period of 8 years (median 8 years, range 3-16 years) the cumulative implant survival rate was 91.7% (SE 0.05). Mean peri-implant bone loss was 0.9mm (SD 1.0mm). Scores for bleeding on probing, plaque and mucosal health were generally low, but significantly worse for posteriorly placed implants. Significantly more biological complications occurred in the posterior group (X 2 (1)=3.9; p=0.048). In 65% of the cases no technical complications were registered. Mean overall OHIP score was 16.1 (SD 18.4) and patients were highly satisfied (VAS: 8.4; SD 2.1). Within the limitations of this retrospective study, in case of a Kennedy class I situation in the mandible, an ISRPD is a viable treatment option with a high implant survival rate and satisfied patients after a maximum of 16 years. Technical and biological complications should be anticipated. Anteriorly placed implants performed slightly better. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  8. Mandibular Overdentures Retained by Two Mini-Implants: A Seven-Year Retention and Satisfaction Study.

    Science.gov (United States)

    Catalán, Alfonso; Martínez, Alejandra; Marchesani, Francisco; González, Urcesino

    2016-07-01

    Patients with atrophic edentulous ridges generally have problems with retention, therapeutic satisfaction, and comfort with their complete dentures. An alternative treatment to assist in improving retention and stability involves the use of mini-implants. The aim of this study was to evaluate the retention of mandibular overdentures connected to two mini-implants and overall patient satisfaction with them. Seven patients with atrophic mandibular ridges (Type 4D Misch classification), aged 62 to 74 years old were rehabilitated with complete dentures. In each patient, two mini-implants measuring 15 or 13 mm in length and 1.8 mm in diameter were placed. After 15 days, overdentures were connected to the mini-implants with O-ring attachments. In each patient, retention of the overdentures was measured, and a survey of therapeutic satisfaction before and after connection to the mini-implants was administered. Prosthesis retention was measured with a digital dynamometer at 1 month, 6 months, and 2, 3, 5, and 7 years after mini-implant placement. Patient satisfaction was assessed with a survey. Data were analyzed with Student's t-test (satisfaction survey) and the Friedman test (retention measurements and satisfaction survey). The initial retention values (0.34 to 0.63 N without mini-implants) varied significantly (p ≤ 0.050). These values were less than the subsequent measurements of 3.92 to 9.64 N, taken after placement of the mini-implants and connecting them to the dentures. Satisfaction was good to very good over the 7-year observation period. Mucosa and peri-implant bone showed no pathological changes. In this limited sample size clinical study the results indicated that after connecting mandibular overdentures to two mini-implants, patient satisfaction significantly increased and retention significantly improved during the 7-year observation period. © 2015 by the American College of Prosthodontists.

  9. Improving the fit of implant prosthetics: an in vitro study.

    Science.gov (United States)

    Yannikakis, Stavros; Prombonas, Anthony

    2013-01-01

    Accurate and passive fit between a prosthesis and its supporting implants has been considered a prerequisite for successful long-term osseointegration. The objective of this in vitro study was to evaluate the strain development during tightening of a five-unit screw-retained superstructure constructed using five different methods. Five-unit screw-retained fixed partial prostheses (n = 25) were fabricated on three implants embedded in an epoxy resin block using five different methods: (1) cobalt-chromium (Co-Cr), plastic cylinders, one-piece cast; (2) Co-Cr, plastic cylinders, framework sectioned, preceramic laser-welding soldering; (3) gold-platinum (Au-Pt), gold cylinders, one-piece cast; (4) Au-Pt, gold cylinders, framework sectioned, preceramic laser-welding soldering; (5) Co-Cr, one-piece cast, and cementation to "passive abutments" (Southern Implants) after final finishing and polishing. Strain gauges (SG) were attached to the fixed partial prosthesis (FPP) and to the resin block to measure the stress created during screw tightening. The combination of Co-Cr alloy and plastic cylinders in a one-piece cast showed such an inadequate fit among the fabricated methods that this group was excluded from the remainder of the experiment. Specimens of Au-Pt cast on gold cylinders in one piece showed higher strain development than the other groups used in this study, with strains ranging from 223.1 to 2,198.1 Μm/m. Sectioning and soldering significantly improved the overall fit. FPPs of Co-Cr in a one-piece cast cemented to "passive abutments" produced the best level of fit, with the least strain development in the prosthesis and the resin block (59 to 204.6 Μm/m). Absolute fit of superstructures on implants is not possible using conventional laboratory procedures. Cementing FPPs onto prefabricated cylinders directly onto the implants significantly reduces strain development compared to the other fabrication methods.

  10. Biomechanical Analysis of Implanted Clavicle Hook Plates With Different Implant Depths and Materials in the Acromioclavicular Joint: A Finite Element Analysis Study.

    Science.gov (United States)

    Lee, Cheng-Hung; Shih, Cheng-Min; Huang, Kui-Chou; Chen, Kun-Hui; Hung, Li-Kun; Su, Kuo-Chih

    2016-11-01

    Clinical implantation of clavicle hook plates is often used as a treatment for acromioclavicular joint dislocation. However, it is not uncommon to find patients that have developed acromion osteolysis or had peri-implant fracture after hook plate fixation. With the aim of preventing complications or fixation failure caused by implantation of inappropriate clavicle hook plates, the present study investigated the biomechanics of clavicle hook plates made of different materials and with different hook depths in treating acromioclavicular joint dislocation, using finite element analysis (FEA). This study established four parts using computer models: the clavicle, acromion, clavicle hook plate, and screws, and these established models were used for FEA. Moreover, implantations of clavicle hook plates made of different materials (stainless steel and titanium alloy) and with different depths (12, 15, and 18 mm) in patients with acromioclavicular joint dislocation were simulated in the biomechanical analysis. The results indicate that deeper implantation of the clavicle hook plate reduces stress on the clavicle, and also reduces the force applied to the acromion by the clavicle hook plate. Even though a clavicle hook plate made of titanium alloy (a material with a lower Young's modulus) reduces the force applied to the acromion by the clavicle hook plate, slightly higher stress on the clavicle may occur. The results obtained in this study provide a better reference for orthopedic surgeons in choosing different clavicle hook plates for surgery. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  11. Expressive Language Development in 45 Cochlear Implanted Children Following 2 Years of Implantation

    Directory of Open Access Journals (Sweden)

    Seyed Basir Hashemi

    2011-10-01

    Full Text Available Objectives: Profound hearing loss encounters children with delay in speech and language. As it is known language acquisition in young deaf children is a lengthy process, but cochlear implanted children have better spoken language skills than if they had not received the device. According to the importance of cochlear implant in deaf child's language development, this study evaluates the effect of different variables on child's language performance. Methods: 45 cochlear implanted children were tested, all of whom had used the device for at least 2 years. In order to evaluate the children, the NEWSHA test which is fitted for Persian speaking children was performed and language development of the children was compared through stepwise discriminant analysis. Results: After evaluation of the effect of different variables like child's age of implantation, participating in rehabilitation classes, parent's cooperation and their level of education, we came to a conclusion that the child's age of implantation and rehabilitation program significantly develop the child's language performance. Discussion: The value of cochlear implant in improvement of deaf children in speech, language perception, production and comprehension is confirmed by different studies which have been done on cochlear implanted children. Also, the present study indicates that language development in cochlear implanted children is highly related to their age of implantation and rehabilitation program.

  12. Non-destructive study of the ion-implantation-affected zone (the long-range effect) in titanium nitride

    International Nuclear Information System (INIS)

    Perry, A.J.; Treglio, J.R.; Schaffer, J.P.; Brunner, J.; Valvoda, V.; Rafaja, D.

    1994-01-01

    The depth to which metal ion implantation can change the structure of titanium nitride coatings is studied using two techniques - positron annihilation spectroscopy (PAS) and glancing-angle X-ray diffraction (GA-XRD) -which are normally applied to the study of bulk materials. The PAS results indicate that the depth to which vacancies are found greatly exceeds the depth at which the implanted material resides. In addition, the concentration of vacancies continues to increase with the dose of implanted ions. The GA-XRD data show that the implantation does not change the residual stress - it remains slightly tensile. Furthermore, there is an increase in the diffraction peak broadening, which is attributed to an increase in the local strain distribution resulting from the generation of a dislocation network at depths of up to several tenths of a micrometer below the implanted zone. The data support the view of a long-range effect, where metal ion implantation causes lattice defect generation within an implantation-affected zone (IAZ) to depths well beyond the implanted zone. The defective nature of the IAZ depends on the implanted dose and the acceleration voltage, as well as on the nature of the ions implanted. In the present work, there is no residual stress in the samples, so this cannot induce the IAZ. ((orig.))

  13. An in vivo assessment of the effects of using different implant abutment occluding materials on implant microleakage and the peri-implant microbiome

    Science.gov (United States)

    Rubino, Caroline

    Microleakage may be a factor in the progression of peri-implant pathology. Microleakage in implant dentistry refers to the passage of bacteria, fluids, molecules or ions between the abutment-implant interface to and from the surrounding periodontal tissues. This creates a zone of inflammation and reservoir of bacteria at the implant-abutment interface. Bone loss typically occurs within the first year of abutment connection and then stabilizes. It has not yet been definitively proven that the occurrence of microleakage cannot contribute to future bone loss or impede the treatment of peri-implant disease. Therefore, strategies to reduce or eliminate microleakage are sought out. Recent evidence demonstrates that the type of implant abutment channel occluding material can affect the amount of microleakage in an in vitro study environment. Thus, we hypothesize that different abutment screw channel occluding materials will affect the amount of observed microleakage, vis-a-vis the correlation between the microflora found on the abutment screw channel occluding material those found in the peri-implant sulcus. Additional objectives include confirming the presence of microleakage in vivo and assessing any impact that different abutment screw channel occluding materials may have on the peri-implant microbiome. Finally, the present study provides an opportunity to further characterize the peri-implant microbiome. Eight fully edentulous patients restored with at dental implants supporting screw-retained fixed hybrid prostheses were included in the study. At the initial appointment (T1), the prostheses were removed and the implants and prostheses were cleaned. The prostheses were then inserted with polytetrafluoroethylene tape (PTFE, TeflonRTM), cotton, polyvinyl siloxane (PVS), or synthetic foam as the implant abutment channel occluding material and sealed over with composite resin. About six months later (T2), the prostheses were removed and the materials collected. Paper

  14. Studies on thoron progeny implantation in different materials

    International Nuclear Information System (INIS)

    Cosma, C.; Flore, A.; Pop, I.

    2003-01-01

    The purpose of this work is to obtain the alpha spectra for thoron daughters implanted at the surface of different materials and to show the possibility of this method to simulate the radon progeny implantation and thus to find some parameters used in the Jacobi model

  15. Anchorage of TiO2-blasted, HA-coated, and machined implants: an experimental study with rabbits

    DEFF Research Database (Denmark)

    Gotfredsen, K; Wennerberg, A; Johansson, C

    1995-01-01

    The purpose of this study was to evaluate the histometrical and biomechanical anchorage of TiO2-blasted implants and TiO2-blasted implants coated with hydroxyapatite. The control implants were machined. Twenty-six rabbits had a total of 156 implants placed in the proximal part of the tibia. Each...... rabbit had a machined, a TiO2-blasted, and a TiO2-blasted, HA-coated implant placed in each tibia. After a healing period of 3 and 12 weeks, respectively, the implants placed in the right tibia were used for removal torque test, and the implants placed in the left tibia were used for histomorphometrical...

  16. Osteogenesis and Morphology of the Peri-Implant Bone Facing Dental Implants

    Directory of Open Access Journals (Sweden)

    Marco Franchi

    2004-01-01

    Full Text Available This study investigated the influence of different implant surfaces on peri-implant osteogenesis and implant face morphology of peri-implant tissues during the early (2 weeks and complete healing period (3 months. Thirty endosseous titanium implants (conic screws with differently treated surfaces (smooth titanium = SS, titanium plasma sprayed = TPS, sand-blasted zirconium oxide = Zr-SLA were implanted in femur and tibiae diaphyses of two mongrel sheep. Histological sections of the implants and surrounding tissues obtained by sawing and grinding techniques were observed under light microscopy (LM. The peri-implant tissues of other samples were mechanically detached from the corresponding implants to be processed for SEM observation. Two weeks after implantation, we observed osteogenesis (new bone trabeculae around all implant surfaces only where a gap was present at the host bone-metal interface. No evident bone deposition was detectable where threads of the screws were in direct contact with the compact host bone. Distance osteogenesis predominated in SS implants, while around rough surfaces (TPS and Zr-SLA, both distance and contact osteogenesis were present. At SEM analysis 2 weeks after implantation, the implant face of SS peri-implant tissue showed few, thin, newly formed, bone trabeculae immersed in large, loose, marrow tissue with blood vessels. Around the TPS screws, the implant face of the peri-implant tissue was rather irregular because of the rougher metal surface. Zr-SLA screws showed more numerous, newly formed bone trabeculae crossing marrow spaces and also needle-like crystals in bone nodules indicating an active mineralising process. After 3 months, all the screws appeared osseointegrated, being almost completely covered by a compact, mature, newly formed bone. However, some marrow spaces rich in blood vessels and undifferentiated cells were in contact with the metal surface. By SEM analysis, the implant face of the peri-implant

  17. Impact of implant design on primary stability of orthodontic mini-implants.

    Science.gov (United States)

    Wilmes, Benedict; Ottenstreuer, Stephanie; Su, Yu-Yu; Drescher, Dieter

    2008-01-01

    Skeletal anchorage with mini-implants has greatly broadened the treatment possibilities in orthodontics over the last few years. To reduce implant failure rates, it is advisable to obtain adequate primary stability. The aim of this study was to quantitatively analyze the impact of implant design and dimension on primary stability. Forty-two porcine iliac bone segments were prepared and embedded in resin. To evaluate the primary stability, we documented insertion torques of the following mini-implants: Aarhus Screw, AbsoAnchor, LOMAS, Micro-Anchorage-System, ORLUS and Spider Screw. In each bone, five Dual Top Screws were inserted for reference purposes to achieve comparability among the specimens. We observed wide variation in insertion torques and hence primary stability, depending on mini-implant design and dimension; the great impact that mini-implant diameter has on insertion torques was particularly conspicuous. Conical mini-implants achieved higher primary stabilities than cylindrical designs. The diameter and design of the mini-implant thread have a distinctive impact on primary stability. Depending on the region of insertion and local bone quality, the choice of the mini-implant design and size is crucial to establish sufficient primary stability.

  18. A 5-year prospective study of single-tooth replacements supported by the Astra Tech implant: a pilot study

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2004-01-01

    BACKGROUND: Implant-supported single-tooth replacements are an increasingly used method to replace teeth, especially in young patients. Therefore, long-term validation of different treatment modalities with different implant systems is of great importance. PURPOSE: The aim of the present study...... was to make a biologic, technical, and aesthetic evaluation of single-tooth replacement supported by the Astra Tech implant (Astra Tech AB, Mölndal, Sweden) during a 5-year period. MATERIALS AND METHODS: Twenty patients were divided into two consecutively treated groups. In group A the implants were placed...... "early" in the extraction sockets, and standard single-tooth abutments were used. In group B the implants were placed "delayed," and preparable abutments were used. Clinical examinations including registration of plaque, bleeding, crown lengths, soft tissue marginal level, papilla height, complications...

  19. Wide-diameter locking-taper implants: a prospective clinical study with 1 to 10-year follow-up

    Directory of Open Access Journals (Sweden)

    C. Mangano

    2014-06-01

    Full Text Available Aim: Wide-diameter implants (WDIs, diameter ≥4.5 mm are increasingly being used in patients with poor bone quality and reduced bone height. The aim of this study was to evaluate the survival rate, peri-implant bone loss, biological and prosthetic complications of wide-diameter (4.8 mm locking-taper implants used in the restoration of partially and fully edentulous patients. Materials and methods: Between January 2002 and December 2011, all patients referred to a private clinic for treatment with WDIs were considered for inclusion in the study. At each annual follow-up session, clinical and radiographic parameters were assessed: the outcome measurements were implant failure, peri-implant bone loss (distance between the implant shoulder and the first visible bone-to-implant contact: DIB, biological and prosthetic complications. The cumulative survival rate (CSR was assessed using the Kaplan-Meier estimator; Log-rank was applied to evaluate correlations between the study variables. The statistical analysis was performed at the patient and at the implant level. Results: A total of 438 WDIs were placed in 411 patients. Four implants failed, for a CSR of 99% (patient-based and 99.1% (implant-based at 10-year follow-up. The CSR did not differ significantly with respect to patients’ gender, age, smoking or parafunctional habit, implant location, position, length, bone type or prosthetic restoration. A mean DIB of 0.34 mm (± 0.23, 0.45 mm (± 0.27 and 0.75 mm (± 0.33 was shown at the 1-, 5- and 10-year follow-up examination. Conclusions: Wide-diameter, locking-taper implants can be a good treatment option for the rehabilitation of partially and fully edentulous patients over the long term.

  20. Does the number of implants have any relation with peri-implant disease?

    Directory of Open Access Journals (Sweden)

    Bernardo Born PASSONI

    2014-10-01

    Full Text Available Objective: The aim of this study was to evaluate the relationship between the number of pillar implants of implant-supported fixed prostheses and the prevalence of periimplant disease. Material and Methods: Clinical and radiographic data were obtained for the evaluation. The sample consisted of 32 patients with implant-supported fixed prostheses in function for at least one year. A total of 161 implants were evaluated. Two groups were formed according to the number of implants: G1 ≤5 implants and G2 >5 implants. Data collection included modified plaque index (MPi, bleeding on probing (BOP, probing depth (PD, width of keratinized mucosa (KM and radiographic bone loss (BL. Clinical and radiographic data were grouped for each implant in order to conduct the diagnosis of mucositis or peri-implantitis. Results: Clinical parameters were compared between groups using Student’s t test for numeric variables (KM, PD and BL and Mann-Whitney test for categorical variables (MPi and BOP. KM and BL showed statistically significant differences between both groups (p<0.001. Implants from G1 – 19 (20.43% – compared with G2 – 26 (38.24% – showed statistically significant differences regarding the prevalence of peri-implantitis (p=0.0210. Conclusion: It seems that more than 5 implants in total fixed rehabilitations increase bone loss and consequently the prevalence of implants with periimplantitis. Notwithstanding, the number of implants does not have any influence on the prevalence of mucositis.

  1. Experiences of patients with implantable cardioverter defibrillator in Turkey: A qualitative study

    Directory of Open Access Journals (Sweden)

    Özgür Aslan

    2012-01-01

    Full Text Available Background. There has been an increase in the number of patients with implantable cardioverter defibrillator (ICD. It isimportant to understand ICD patients’ experiences with it.Aim. The aim of this study was to describe experiences of patients with implantable cardioverter defibrillator (ICD.Methodology. A qualitative approach was used. Focus group interviews were used to obtain data from 19 patients whowere implanted cardioverter defibrillator at two centers in Izmir, Turkey. The patients were assigned into four groups. Thedata was analyzed using qualitative content analysis.Results. The analysis revealed six main themes: activities of daily living, social life, familial relationships, emotionalchanges, implantable cardioverter defibrillator shocks and experiences with receiving information and counselling fromhealth care providers.Conclusions. It can be concluded that patients with ICD experience physical and psychological problems and are not offeredthe education they need. To reduce the fears of the patients and their families and to prepare them for possible life stylechanges, comprehensive training programs that start in the pre-implantation period and continue into the post-implantationperiod should be organized.

  2. R&D on dental implants breakage

    Science.gov (United States)

    Croitoru, Sorin Mihai; Popovici, Ion Alexandru

    2017-09-01

    Most used dental implants for human dental prostheses are of two steps type: first step means implantation and, after several months healing and osseointegration, second step is prosthesis fixture. For sure, dental implants and prostheses are meant to last for a lifetime. Still, there are unfortunate cases when dental implants break. This paper studies two steps dental implants breakage and proposes a set of instruments for replacement and restoration of the broken implant. First part of the paper sets the input data of the study: structure of the studied two steps dental implants based on two Romanian patents and values of the loading forces found in practice and specialty papers. In the second part of the paper, using DEFORM 2D™ FEM simulation software, worst case scenarios of loading dental implants are studied in order to determine which zones and components of the dental implant set are affected (broken). Last part of the paper is dedicated to design and presentation of a set for extracting and cutting tools used to restore the broken implant set.

  3. Analysis of the influence of the macro- and microstructure of dental zirconium implants on osseointegration: a minipig study.

    Science.gov (United States)

    Mueller, Cornelia Katharina; Solcher, Philipp; Peisker, Andrè; Mtsariashvilli, Maia; Schlegel, Karl Andreas; Hildebrand, Gerhard; Rost, Juergen; Liefeith, Klaus; Chen, Jiang; Schultze-Mosgau, Stefan

    2013-07-01

    It was the aim of this study to analyze the influence of implant design and surface topography on the osseointegration of dental zirconium implants. Six different implant designs were tested in the study. Nine or 10 test implants were inserted in the frontal skull in each of 10 miniature pigs. Biopsies were harvested after 2 and 4 months and subjected to microradiography. No significant differences between titanium and zirconium were found regarding the microradiographically detected bone-implant contact (BIC). Cylindric zirconium implants showed a higher BIC at the 2-month follow-up than conic zirconium implants. Among zirconium implants, those with an intermediate Ra value showed a significantly higher BIC compared with low and high Ra implants 4 months after surgery. Regarding osseointegration, titanium and zirconium showed equal properties. Cylindric implant design and intermediate surface roughness seemed to enhance osseointegration. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Clinical outcomes of immediate/early loading of dental implants. A literature review of recent controlled prospective clinical studies.

    Science.gov (United States)

    Sennerby, L; Gottlow, J

    2008-06-01

    Two previous reviews have evaluated the clinical outcomes of immediate/early loading of dental implants based on studies published until 2005.(1,2) The aim of the present paper was to review controlled clinical studies on the subject published since 2005 including at least 10 patients in each group followed for at least one year in function. Six comparative studies were found and none of these showed any differences in survival rates or marginal bone loss after one to five years. Most authors used specified inclusion criteria to avoid known risk factors such as soft bone, short implants and bruxism. Data from one randomized study in the edentulous maxilla showed no differences between early and delayed loading in consecutive clinical routine cases including short implants and soft bone. Three additional studies comparing different surfaces or implant designs under immediate loading were reviewed. No differences between implants with a moderately rough or smooth surface topography were observed. The data add to the previous bulk of evidence that various designs of implants can be loaded shortly after their placement in both the mandible and the maxilla. However, one study reported on marginal bone loss around a novel one-piece implant design leading to implant failure which was not seen for control two-piece implants.(3).

  5. The team approach to managing dental implant complications: the periodontist's point of view.

    Science.gov (United States)

    Froum, Stuart J

    2013-10-01

    Implant-related complications are a fact of life among practitioners who place or restore implants. They occur for a variety of reasons with varying consequences. Those classified as minor complications are most easily corrected and may have little impact on the course of treatment, but severe complications can have serious consequence in expense, complexity, and ultimate success. Many severe complications may be irreversible, leaving the patient with less desirable esthetic options, or worse, permanent disability in terms of speech and function. While various members of the dental team may have different points of view, implant complications are a concern to all. Successful results require comprehensive care, collaborative treatment, and knowledge of dental implant complications. Therefore, it is in the best interest of the patient that all involved in treatment be aware of the different types of complications that can be experienced and learn how to work together as a team to achieve successful outcomes.

  6. Anodized dental implant surface

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Mishra

    2017-01-01

    Full Text Available Purpose: Anodized implants with moderately rough surface were introduced around 2000. Whether these implants enhanced biologic effect to improve the environment for better osseointegration was unclear. The purpose of this article was to review the literature available on anodized surface in terms of their clinical success rate and bone response in patients till now. Materials and Methods: A broad electronic search of MEDLINE and PubMed databases was performed. A focus was made on peer-reviewed dental journals. Only articles related to anodized implants were included. Both animal and human studies were included. Results: The initial search of articles resulted in 581 articles on anodized implants. The initial screening of titles and abstracts resulted in 112 full-text papers; 40 animal studies, 16 studies on cell adhesion and bacterial adhesion onto anodized surfaced implants, and 47 human studies were included. Nine studies, which do not fulfill the inclusion criteria, were excluded. Conclusions: The long-term studies on anodized surface implants do favor the surface, but in most of the studies, anodized surface is compared with that of machined surface, but not with other surfaces commercially available. Anodized surface in terms of clinical success rate in cases of compromised bone and immediately extracted sockets has shown favorable success.

  7. Osseointegration of a 3D Printed Stemmed Titanium Dental Implant: A Pilot Study

    OpenAIRE

    James Tedesco; Bryan E. J. Lee; Alex Y. W. Lin; Dakota M. Binkley; Kathleen H. Delaney; Jacek M. Kwiecien; Kathryn Grandfield

    2017-01-01

    In this pilot study, a 3D printed Grade V titanium dental implant with a novel dual-stemmed design was investigated for its biocompatibility in vivo. Both dual-stemmed (n = 12) and conventional stainless steel conical (n = 4) implants were inserted into the tibial metaphysis of New Zealand white rabbits for 3 and 12 weeks and then retrieved with the surrounding bone, fixed, dehydrated, and embedded into epoxy resin. The implants were analyzed using correlative histology, microcomputed tomogra...

  8. Evaluation of primary stability of self-tapping and non-self-tapping dental implants. A 12-week clinical study.

    Science.gov (United States)

    Marković, Aleksa; Calvo-Guirado, José Luís; Lazić, Zoran; Gómez-Moreno, Gerardo; Ćalasan, Dejan; Guardia, Javier; Čolic, Snježana; Aguilar-Salvatierra, Antonio; Gačić, Bojan; Delgado-Ruiz, Rafael; Janjić, Bojan; Mišić, Tijana

    2013-06-01

    The aim of this study was to investigate the relationship between surgical techniques and implant macro-design (self-tapping/non-self-tapping) for the optimization of implant stability in the low-density bone present in the posterior maxilla using resonance frequency analysis (RFA). A total of 102 implants were studied. Fifty-six self-tapping BlueSkyBredent® (Bredent GmbH&Co.Kg®, Senden, Germany) and 56 non-self-tapping Standard Plus Straumann® (Institut Straumann AG®, Waldenburg, Switzerland) were placed in the posterior segment of the maxilla. Implants of both types were placed in sites prepared with either lateral bone-condensing or with bone-drilling techniques. Implant stability measurements were performed using RFA immediately after implant placement and weekly during a 12-week follow-up period. Both types of implants placed after bone condensing achieved significantly higher stability immediately after surgery, as well as during the entire 12-week observation period compared with those placed following bone drilling. After bone condensation, there were no significant differences in primary stability or in implant stability after the first week between both implant types. From 2 to 12 postoperative weeks, significantly higher stability was shown by self-tapping implants. After bone drilling, self-tapping implants achieved significantly higher stability than non-self-tapping implants during the entire follow-up period. The outcomes of the present study indicate that bone drilling is not an effective technique for improving implant stability and, following this technique, the use of self-tapping implants is highly recommended. Implant stability optimization in the soft bone can be achieved by lateral bone-condensing technique, regardless of implant macro-design. © 2011 Wiley Periodicals, Inc.

  9. Evaluation of mandibular posterior single implants with two different surfaces: a 5-year comparative study.

    Science.gov (United States)

    Jung, Ui-Won; Choi, Jung-Yoo; Kim, Chang-Sung; Cho, Kyoo-Sung; Chai, Jung-Kiu; Kim, Chong-Kwan; Choi, Seong-Ho

    2008-10-01

    Anatomic and biomechanical limitations can jeopardize successful single implantation in the mandibular posterior area. To overcome the limitations, the design and the surface of the fixtures were modified. This study evaluated the cumulative survival rate (CSR) of mandibular molars replaced with a sand-blasted, large-grit, acid-etched (SLA) single implant or an anodized (ANO) single implant and examined associated factors, such as the surface treatment, position, and length and diameter of the implants. One hundred ninety-three single implants restored with an SLA implant and 112 single implants restored with an ANO implant in the mandibular molar area were selected from subjects who had visited the Department of Periodontology, Dental Hospital of Yonsei University, from March 2001 through June 2006. In the SLA group, 123 and 70 implants were placed in the first and second molar area, respectively. In the ANO group, 55 and 57 implants were placed in the first and second molar area, respectively. The 1- to 6-year CSR of the SLA and ANO groups was calculated using the life-table analysis. In addition, associated factors, such as the surface treatment, position, and length and diameter of the implants, were compared and analyzed using the chi(2) test (P CSR of 98.96%; four of 112 ANO implants failed, giving a CSR of 96.43%. There were no significant differences with regard to the surface treatment, position, and length and diameter of the implants. Despite the anatomic and biomechanical limitation in the mandibular posterior area, mandibular posterior single implants showed a high CSR during the observation period. Mandibular posterior single implants can be an effective and reliable treatment modality that is not affected by the surface treatment, position, or length and diameter of the implant.

  10. Comparison of three-implant-supported fixed dentures and two-implant-retained overdentures in the edentulous mandible: a pilot study of treatment efficacy and patient satisfaction.

    Science.gov (United States)

    De Kok, Ingeborg J; Chang, Kuang-Han; Lu, Tsui-Shan; Cooper, Lyndon F

    2011-01-01

    The mandibular two-implant overdenture has been shown to be a highly successful treatment. However, overdenture patients who desire a fixed prosthesis may not be satisfied with a removable overdenture. This prospective study sought to compare prosthetic outcomes, patient satisfaction, and survival rates of implants between two-implant-supported overdentures (IODs) and three-implant-supported fixed dentures (ISFDs). Twenty completely edentulous patients were randomly and equally assigned to two groups. New conventional complete dentures were made, and the mandibular denture was used as a surgical guide during implant placement. Implants were placed in one stage, followed by a mandibular denture soft reline (provisional loading). Ball attachments were inserted at 8 weeks, and ISFDs were delivered at 16 weeks. IODs were connected to the attachments at 8 weeks, using each patients's existing denture. The definitive ISFDs were fabricated using computer-aided design/computer-assisted manufacture milled titanium frameworks and acrylic resin base and teeth. Patient satisfaction and panoramic radiographs were investigated at 6 and 12 months. Both treatments had significant and positive effects on patient satisfaction and quality of life. None of the 50 implants placed had failed at 12 months of follow-up; therefore, the implant survival rate was 100%. Prosthetic complications were generally rare and easily manageable. Both the treatment modalities-the ISFD supported by three implants and the IOD supported by two implants-significantly and similarly improved patient satisfaction and oral health-related quality of life, and prosthetic complications were relatively rare for both treatments. Three implants can be used to support a mandibular fixed prosthesis; however, a longer observation period is needed to validate this treatment modality.

  11. Long-term prospective cohort study on dental implants: clinical and microbiological parameters.

    Science.gov (United States)

    Tenenbaum, Henri; Bogen, Omer; Séverac, François; Elkaim, René; Davideau, Jean-Luc; Huck, Olivier

    2017-01-01

    The aim of the present prospective cohort study is to evaluate clinical and microbiological data of dental implants after at least 8 years of follow-up. A total of 110 patients and 232 implants were included at baseline and followed during 1 year. Fifty-two patients and 108 implants could be evaluated at the final examination. Clinical and microbiological data were taken at baseline, 1 year and at least 8 years. The mean follow-up time was 10.8 ± 1.7 years. Plaque index was, respectively, 0.50 ± 0.50 at baseline, 0.50 ± 0.50 at 1 year and 0.33 ± 0.67 at ≥8 years. Gingival index was, respectively, 1.08 ± 0.19 at baseline, 1.01 ± 0.39 at 1 year and 0.22 ± 0.47 at ≥8 years. Sulcular bleeding index was, respectively, 0.17 ± 0.22 at baseline, 0.11 ± 0.33 at 1 year and 0.17 ± 0.22 at ≥8 years. Probing depth was, respectively, 2.67 ± 0.75 at baseline, 3.00 ± 0.83 at 1 year and 2.74 ± 1.00 at ≥8 years. Clinical attachment level was, respectively, 3.75 ± 1.17 at baseline, 4.00 ± 1.06 at 1 year and 4.00 ± 1.17 at ≥8 years. Peri-implant mucositis was detected around 60.2% of implants in 73.1% of patients, while peri-implantitis was affecting 12% of implants in 15.4% of patients. Some bacteria species were associated with worsened clinical parameters. About 69.4% of implants (75/108) and 67.3% of the patients (35/52) were considered as success in the present prospective cohort study after a mean follow-up of 10.8 years. Microbial follow-up may help to identify patients at risk for peri-implant disease. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Maxillary implant-supported overdentures opposed by (partial) natural dentitions: a 5-year prospective case series study.

    Science.gov (United States)

    Boven, G C; Slot, J W A; Raghoebar, G M; Vissink, A; Meijer, H J A

    2017-12-01

    The aim of this study was to assess the 5-year treatment outcome of maxillary implant-retained overdentures opposed by natural antagonistic teeth. Fifty consecutive patients received maxillary overdentures supported by six dental implants. Implants were placed in the anterior region, if enough bone was present (n = 25 patients) Implant were placed in the posterior region if implant placement in the anterior region was not possible (n = 25 patients). Variables assessed included survival of implants, condition of hard and soft peri-implant tissues and patients' satisfaction. The five-year implant survival rate was 97·0% and 99·3%, and mean radiographic bone loss was 0·23 and 0·69 mm in the anterior and posterior group, respectively. Median scores for plaque, calculus, gingiva, bleeding and mean scores for pocket probing depth were low and stayed low. Patients' satisfaction after treatment was high in both groups. Within the limits of this 5-year study, it is concluded that six dental implants (placed in the anterior or posterior region) connected with a bar and opposed to natural antagonistic teeth result in acceptable results for clinical parameters and good outcomes for marginal bone level changes and patient satisfaction. © 2017 John Wiley & Sons Ltd.

  13. Effect of insertion torque on titanium implant osseointegration: an animal experimental study.

    Science.gov (United States)

    Duyck, Joke; Roesems, Rutger; Cardoso, Marcio V; Ogawa, Toru; De Villa Camargos, Germana; Vandamme, Katleen

    2015-02-01

    To evaluate the effect of implant insertion torque on the peri-implant bone healing and implant osseointegration. Bilaterally in the tibia of five adult New Zealand white rabbits, 20 implants were installed, subdivided into four groups, corresponding to two insertion torque conditions (low, 50 Ncm) and 2 experimental periods (2 weeks vs. 4 weeks of healing). The implant insertion torque was determined by the surgical drill diameter relative to the implant diameter. Implant osseointegration was evaluated by quantitative histology (bone-to-implant contact with host bone [BIC-host], with neoformed bone [BIC-de novo], with both bone types [BIC-total], and peri-implant bone [BA/TA]). Every response was modelled over time using GEE (general estimation equation) with an unstructured variance-covariance matrix to correct for dependency between the measurements from one animal. The statistical significance level of α = 0.05 was applied. Significantly, more BIC-host and BIC-total were recorded for H implants compared with L implants after 2 week of healing (P = 0.010 and P = 0.0001, respectively). However, this result was no longer found for the extended healing period. Furthermore, BIC-total significantly increased over time for L implants (P torque led to an increased BA/TA after 4 week of healing (P torque implants installed in the rabbit tibial bone osseointegrate with considerable de novo bone formation. This bone neoformation enables L implants to catch up, already during the early osseointegration stage, the initial inferior amount BIC contact compared with that of H implants. A negative impact of the created strain environment accompanying H insertion torque implant installation on the biological process of osseointegration could not be observed, at least not at tissue level. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Stability studies of Hg implanted YBa$_{2}$Cu$_{3}$O$_{6+x}$

    CERN Document Server

    Araújo, J P; Wahl, U; Marques, J G; Alves, E; Amaral, V S; Lourenço, A A; Galindo, V; Von Papen, T; Senateur, J P; Weiss, F; Vantomme, A; Langouche, G; Melo, A A; Da Silva, M F A; Soares, J C; Sousa, J B

    1999-01-01

    High quality YBa$_{2}$Cu$_{3}$O$_{6+x}$ (YBCO) superconducting thin films were implanted with the radioactive $^{197m}$Hg (T$_{1/2}$ = 24 h) isotope to low fluences of 10$^{13}$ atoms/cm$^{2}$ and 60 keV energy. The lattice location and stability of the implanted Hg were studied combining the Perturbed Angular Correlation (PAC) and Emission Channeling (EC) techniques. We show that Hg can be introduced into the YBCO lattice by ion implantation into unique regular sites. The EC data show that Hg is located on a highly symmetric site on the YBCO lattice, while the PAC data suggests that Hg occupies the Cu(1) site. Annealing studies were performed under vacuum and O$_{2}$ atmosphere and show that Hg starts to diffuse only above 653 K.

  15. Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany)]. E-mail: walter.assmann@lmu.de; Schubert, M. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany); Held, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany); Pichler, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Muenchen (Germany); Chill, A. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Kiermaier, S. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Schloesser, K. [Forschungszentrum Karlsruhe, 76021 Karlsruhe (Germany); Busch, H. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Schenk, K. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Streufert, D. [Acri.Tec GmbH, 16761 Hennigsdorf (Germany); Lanzl, I. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany)

    2007-04-15

    A biodegradable, {beta}-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the {beta}-emitter {sup 32}P. The influence of ion implantation and gamma sterilisation on degradation and {sup 32}P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (10{sup 15} ions/cm{sup 2}) and gamma dose (25 kGy) are found to be tolerable.

  16. Coherent Synchrotron-Based Micro-Imaging Employed for Studies of Micro-Gap Formation in Dental Implants

    International Nuclear Information System (INIS)

    Rack, T.; Stiller, M.; Nelson, K.; Zabler, S.; Rack, A.; Riesemeier, H.; Cecilia, A.

    2011-01-01

    Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process.

  17. Cochlear implant benefits in deafness rehabilitation: PET study of temporal voice Activations

    Energy Technology Data Exchange (ETDEWEB)

    Coez, A.; Zilbovicius, M. [CEA, Serv Hosp Frederic Joliot, INSERM, Res Unit Neuroimaging and Psychiat, U797, IFR49, F-91406 Orsay (France); Zilbovicius, M.; Syrota, A.; Samson, Y. [CEA, DSV, DRM, Serv Hosp Frederic Joliot, F-91406 Orsay (France); Bizaguet, E. [Lab Correct Audit, Paris (France); Coez, A. [Univ Paris Sud 11, Paris (France); Ferrary, E.; Bouccara, D.; Mosnier, I.; Sterkers, O. [INSERM, Unit M 867, Paris (France); Ambert-Dahan, E. [Hop Beaujon, Serv ORL Chirurg Cervicofaciale, AP-HP, Clichy (France); Ferrary, E.; Bouccara, D.; Mosnier, I.; Sterkers, O. [Inst Fed Rech Claude Bernard Physiol et Pathol, IFR02, Paris (France); Samson, Y. [Hop La Pitie Salpetriere, Serv Urgences Cerebro-vasc, AP-HP, Paris (France); Samson, Y. [Univ Paris 06, Paris (France); Sterkers, O. [Univ Denis Diderot Paris 7, Paris (France)

    2008-07-01

    Cochlear implants may improve the medical and social prognosis of profound deafness. Nevertheless, some patients have experienced poor results without any clear explanations. One correlate may be an alteration in cortical voice processing. To test this hypothesis, we studied the activation of human temporal voice areas (TVA) using a well-standardized PET paradigm adapted from previous functional MRI (fMRI) studies. Methods: A PET H{sub 2}{sup 15}O activation study was performed on 3 groups of adult volunteers: normal-hearing control subjects (n 6) and cochlear-implanted post-lingually deaf patients with {>=}2 y of cochlear implant experience, with intelligibility scores in the 'Lafon monosyllabic task' {>=}80% (Good group; n 6) or {<=}20% (Poor group; n 6). Relative cerebral blood flow was measured in 3 conditions: rest, passive listening to human voice, and non-voice stimuli. Results: Compared with silence, the activations induced by non-voice stimuli were bilaterally located in the superior temporal regions in all groups. However these activations were significantly and similarly reduced in both cochlear implant groups, whereas control subjects showed supplementary activations. Compared with non-voice, the voice stimuli induced bilateral activation of the TVA along the superior temporal sulcus (STS) in both the control and the Good groups. In contrast, these activations were not detected in the Poor group, which showed only left unilateral middle STS activation. Conclusion: These results suggest that PET is an adequate method to explore cochlear implant benefits and that this benefit could be linked to the activation of the TVA. (authors)

  18. Cochlear implant benefits in deafness rehabilitation: PET study of temporal voice Activations

    International Nuclear Information System (INIS)

    Coez, A.; Zilbovicius, M.; Zilbovicius, M.; Syrota, A.; Samson, Y.; Bizaguet, E.; Coez, A.; Ferrary, E.; Bouccara, D.; Mosnier, I.; Sterkers, O.; Ambert-Dahan, E.; Ferrary, E.; Bouccara, D.; Mosnier, I.; Sterkers, O.; Samson, Y.; Samson, Y.; Sterkers, O.

    2008-01-01

    Cochlear implants may improve the medical and social prognosis of profound deafness. Nevertheless, some patients have experienced poor results without any clear explanations. One correlate may be an alteration in cortical voice processing. To test this hypothesis, we studied the activation of human temporal voice areas (TVA) using a well-standardized PET paradigm adapted from previous functional MRI (fMRI) studies. Methods: A PET H 2 15 O activation study was performed on 3 groups of adult volunteers: normal-hearing control subjects (n 6) and cochlear-implanted post-lingually deaf patients with ≥2 y of cochlear implant experience, with intelligibility scores in the 'Lafon monosyllabic task' ≥80% (Good group; n 6) or ≤20% (Poor group; n 6). Relative cerebral blood flow was measured in 3 conditions: rest, passive listening to human voice, and non-voice stimuli. Results: Compared with silence, the activations induced by non-voice stimuli were bilaterally located in the superior temporal regions in all groups. However these activations were significantly and similarly reduced in both cochlear implant groups, whereas control subjects showed supplementary activations. Compared with non-voice, the voice stimuli induced bilateral activation of the TVA along the superior temporal sulcus (STS) in both the control and the Good groups. In contrast, these activations were not detected in the Poor group, which showed only left unilateral middle STS activation. Conclusion: These results suggest that PET is an adequate method to explore cochlear implant benefits and that this benefit could be linked to the activation of the TVA. (authors)

  19. DIY 3D printing of custom orthopaedic implants: a proof of concept study.

    Science.gov (United States)

    Frame, Mark; Leach, William

    2014-03-01

    3D printing is an emerging technology that is primarily used for aiding the design and prototyping of implants. As this technology has evolved it has now become possible to produce functional and definitive implants manufactured using a 3D printing process. This process, however, previously required a large financial investment in complex machinery and professionals skilled in 3D product design. Our pilot study's aim was to design and create a 3D printed custom orthopaedic implant using only freely available consumer hardware and software.

  20. Electron microscopy studies of ion implanted silicon

    International Nuclear Information System (INIS)

    Seshan, K.

    1975-11-01

    The nature of defects resulting from the implantation of phosphorous ions into doped silicon and a model of how they form are reported. This involved an electron microscope study of the crystallographic defects (in the 300A size range in concentration of 10 15 /cm 3 ) that form upon annealing. Images formed by these crystallographic defects are complex and that nonconventional imaging techniques are required for their characterization. The images of these small defects (about 300A) are sensitive to various parameters, such as foil thickness, their position in the foil, and diffracting conditions. The defects were found to be mostly interstitial hexagonal Frank loops lying on the four [111] planes and a few perfect interstitial loops; these loops occurred in concentrations of about 10 16 /cm 3 . In addition, ''rod like'' linear defects that are shown to be interstitial are also found in concentrations of 10 13 /cm 3 . It was found that the linear defects require boron for their formation. A model is proposed to account for the interstitial defects. The number of point defects that make up the defects is of the same order as the number of implanted ions. The model predicts that only interstitial loops ought to be observed in agreement with several recent investigations. Dislocation models of the loops are examined and it is shown that phosphorous ions could segregate to the Frank loops, changing their displacement vectors to a/x[111]. (x greater than 3) thus explaining the contrast effects observed. It would also explain the relative electrical inactivity of P + ion implants

  1. A study of ion implanted gallium arsenide using deep level transient spectroscopy

    International Nuclear Information System (INIS)

    Emerson, N.G.

    1981-03-01

    This thesis is concerned with the study of deep energy levels in ion implanted gallium arsenide (GaAs) using deep level transient spectroscopy (D.L.T.S.). The D.L.T.S. technique is used to characterise deep levels in terms of their activation energies and capture cross-sections and to determine their concentration profiles. The main objective is to characterise the effects on deep levels, of ion implantation and the related annealing processes. In the majority of cases assessment is carried out using Schottky barrier diodes. Low doses of selenium ions 1 to 3 x 10 12 cm -2 are implanted into vapour phase epitaxial (V.P.E.) GaAs and the effects of post-implantation thermal and pulsed laser annealing are compared. The process of oxygen implantation with doses in the range 1 x 10 12 to 5 x 10 13 cm -2 followed by thermal annealing at about 750 deg C, introduces a deep level at 0.79 eV from the conduction band. Oxygen implantation, at doses of 5 x 10 13 cm -2 , into V.P.E. GaAs produces a significant increase in the concentration of the A-centre (0.83 eV). High doses of zinc (10 15 cm -2 ) are implanted into n-type V.P.E. GaAs to form shallow p-type layers. The D.L.T.S. system described in the text is used to measure levels in the range 0.16 to 1.1 eV (for GaAs) with a sensitivity of the order 1:10 3 . (U.K.)

  2. The effect of varying implant position in immediately loaded implant-supported mandibular overdentures.

    Science.gov (United States)

    Shaarawy, Mohammed A; Aboelross, Ehab M

    2013-06-01

    This study was carried out to evaluate the effect of varying implant position in immediately loaded implant-supported mandibular overdentures on peri-implant bone density, muscle activity, and patient satisfaction. Fourteen completely edentulous patients were selected for the study. After complete denture construction, patients were divided into 2 equal groups. Four dental implants were installed bilaterally in the interforaminal region in the first group, while in the second group, 4 dental implants were inserted bilaterally: 2 in the interforaminal region and 2 in the first molar area. Immediately after suturing, telescopic abutments were screwed to the implants, and the retaining caps were picked up into the fitting surface of the lower denture, which was delivered to the patient. Patients were recalled for radiographic bone density evaluation just after denture delivery and then at 3, 6, and 12 months thereafter. Muscle activities of masseter and temporalis muscles as well as patient satisfaction were also evaluated. The results of the study showed a high success rate approximating 98.2% of the immediately loaded implants. The electromyographic (EMG) records of both muscles in group 1 were significantly higher during chewing hard food after 3 months compared with group 2 (P overdentures through posterior placement beyond the interforaminal area results in a favorable response in terms of increased peri-implant bone density as well as decreased EMG activity of masseter and temporalis muscles.

  3. Depth of valve implantation, conduction disturbances and pacemaker implantation with CoreValve and CoreValve Accutrak system for Transcatheter Aortic Valve Implantation, a multi-center study.

    Science.gov (United States)

    Lenders, Guy D; Collas, Valérie; Hernandez, José Maria; Legrand, Victor; Danenberg, Haim D; den Heijer, Peter; Rodrigus, Inez E; Paelinck, Bernard P; Vrints, Christiaan J; Bosmans, Johan M

    2014-10-20

    Transcatheter Aortic Valve Implantation (TAVI) is now considered an indispensable treatment strategy in high operative risk patients with severe, symptomatic aortic stenosis. However, conduction disturbances and the need for Permanent Pacemaker (PPM) implantation after TAVI with the CoreValve prosthesis still remain frequent. We aimed to evaluate the implantation depth, the incidence and predictors of new conduction disturbances, and the need for PPM implantation within the first month after TAVI, using the new Accutrak CoreValve delivery system (ACV), compared to the previous generation CoreValve (non-ACV). In 5 experienced TAVI-centers, a total of 120 consecutive non-ACV and 112 consecutive ACV patients were included (n=232). The mean depth of valve implantation (DVI) was 8.4±4.0 mm in the non-ACV group and 7.1±4.0 mm in the ACV group (p=0.034). The combined incidence of new PPM implantation and new LBBB was 71.2% in the non-ACV group compared to 50.5% in the ACV group (p=0.014). DVI (p=0.002), first degree AV block (p=0.018) and RBBB (p<0.001) were independent predictors of PPM implantation. DVI (p<0.001) and pre-existing first degree AV-block (p=0.021) were identified as significant predictors of new LBBB. DVI is an independent predictor of TAVI-related conduction disturbances and can be reduced by using the newer CoreValve Accutrak delivery system, resulting in a significantly lower incidence of new LBBB and new PPM implantation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Effect of Heavy Smoking on Dental Implants Placed in Male Patients Posterior Mandibles: A Prospective Clinical Study.

    Science.gov (United States)

    Sun, Cong; Zhao, Jinxiu; Jianghao, Chen; Hong, Tao

    2016-12-01

    The objective of this study was to evaluate the implant stability and peri-implant tissue response in heavy smokers receiving dental implants due to partially edentulous posterior mandibles. Forty-five ITI Straumann dental implants were placed into the partially edentulous posterior mandibles of 16 heavy smokers and 16 nonsmokers. One implant in each patient was evaluated for implant stability after surgery and before loading, and for the modified plaque index (mPLI), modified sulcus bleeding index (mSBI), probing depth (PD), and marginal bone loss (MBL) after loading. Meanwhile, the osteogenic capability of jaw marrow samples collected from patients was evaluated via an in vitro mineralization test. For both groups, the implant stability quotient (ISQ) initially decreased from the initial ISQ achieved immediately after surgery and then increased starting from 2 weeks postsurgery. However, at 3, 4, 6, and 8 weeks postsurgery, the ISQ differed significantly between nonsmokers and heavy smokers. All implants achieved osseointegration without complications at least by the end of the 12th week postsurgery. At 6 or 12 months postloading, the MBL and PD were significantly higher in heavy smokers than in nonsmokers, whereas the mSBI and mPLI did not differ significantly between the 2 groups. The 1-year cumulative success rate of implants was 100% for both groups. Within the limitations of the present clinical study (such as small sample size and short study duration), which applied the loading at 3 months postoperation, heavy smoking did not affect the cumulative survival rate of dental implants placed at the posterior mandible in male patients, but heavy smoking did negatively affect bone healing around dental implants by decreasing the healing speed. These results implied that it might be of importance to select the right time point to apply the implant loading for heavy smokers. In addition, heavy smoking promoted the loss of marginal bone and the further development

  5. Studies on the surface modification of TiN coatings using MEVVA ion implantation with selected metallic species

    International Nuclear Information System (INIS)

    Ward, L.P.; Purushotham, K.P.; Manory, R.R.

    2016-01-01

    Highlights: • Reduced surface roughness was observed after ion implantation. • W implantation increased residual stress. • Reduced friction and wear accompanied Mo implantation. • Mo implanted layer was more resistant to breakdown during wear testing. • Ion implantation effects can be complex on various implanting species properties. - Abstract: Improvement in the performance of TiN coatings can be achieved using surface modification techniques such as ion implantation. In the present study, physical vapor deposited (PVD) TiN coatings were implanted with Cr, Zr, Nb, Mo and W using the metal evaporation vacuum arc (MEVVA) technique at a constant nominal dose of 4 × 10 16 ions cm −2 for all species. The samples were characterized before and after implantation, using Rutherford backscattering (RBS), glancing incident angle X-ray diffraction (GIXRD), atomic force microscopy (AFM) and optical microscopy. Friction and wear studies were performed under dry sliding conditions using a pin-on-disc CSEM Tribometer at 1 N load and 450 m sliding distance. A reduction in the grain size and surface roughness was observed after implantation with all five species. Little variation was observed in the residual stress values for all implanted TiN coatings, except for W implanted TiN which showed a pronounced increase in compressive residual stress. Mo-implanted samples showed a lower coefficient of friction and higher resistance to breakdown during the initial stages of testing than as-received samples. Significant reduction in wear rate was observed after implanting with Zr and Mo ions compared with unimplanted TiN. The presence of the Ti 2 N phase was observed with Cr implantation.

  6. Quantitative ion implantation

    International Nuclear Information System (INIS)

    Gries, W.H.

    1976-06-01

    This is a report of the study of the implantation of heavy ions at medium keV-energies into electrically conducting mono-elemental solids, at ion doses too small to cause significant loss of the implanted ions by resputtering. The study has been undertaken to investigate the possibility of accurate portioning of matter in submicrogram quantities, with some specific applications in mind. The problem is extensively investigated both on a theoretical level and in practice. A mathematical model is developed for calculating the loss of implanted ions by resputtering as a function of the implanted ion dose and the sputtering yield. Numerical data are produced therefrom which permit a good order-of-magnitude estimate of the loss for any ion/solid combination in which the ions are heavier than the solid atoms, and for any ion energy from 10 to 300 keV. The implanted ion dose is measured by integration of the ion beam current, and equipment and techniques are described which make possible the accurate integration of an ion current in an electromagnetic isotope separator. The methods are applied to two sample cases, one being a stable isotope, the other a radioisotope. In both cases independent methods are used to show that the implantation is indeed quantitative, as predicted. At the same time the sample cases are used to demonstrate two possible applications for quantitative ion implantation, viz. firstly for the manufacture of calibration standards for instrumental micromethods of elemental trace analysis in metals, and secondly for the determination of the half-lives of long-lived radioisotopes by a specific activity method. It is concluded that the present study has advanced quantitative ion implantation to the state where it can be successfully applied to the solution of problems in other fields

  7. Influence of controlled immediate loading and implant design on peri-implant bone formation.

    Science.gov (United States)

    Vandamme, Katleen; Naert, Ignace; Geris, Liesbet; Vander Sloten, Jozef; Puers, Robert; Duyck, Joke

    2007-02-01

    Tissue formation at the implant interface is known to be sensitive to mechanical stimuli. The aim of the study was to compare the bone formation around immediately loaded versus unloaded implants in two different implant macro-designs. A repeated sampling bone chamber with a central implant was installed in the tibia of 10 rabbits. Highly controlled loading experiments were designed for a cylindrical (CL) and screw-shaped (SL) implant, while the unloaded screw-shaped (SU) implant served as a control. An F-statistic model with alpha=5% determined statistical significance. A significantly higher bone area fraction was observed for SL compared with SU (pimplant contact occurred was the highest for SL and significantly different from SU (pimplant contact was observed, a loading (SL versus SU: p=0.0049) as well as an implant geometry effect (SL versus CL: p=0.01) was found, in favour of the SL condition. Well-controlled immediate implant loading accelerates tissue mineralization at the interface. Adequate bone stimulation via mechanical coupling may account for the larger bone response around the screw-type implant compared with the cylindrical implant.

  8. Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

    International Nuclear Information System (INIS)

    Zuki, Mervet El; Omami, Galal; Horner, Keith

    2014-01-01

    The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

  9. Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Zuki, Mervet El [Dept. of Oral Medicine and Radiology, Benghazi University College of Dentistry, Benghazi (Libya); Omami, Galal [Oral Diagnosis and Polyclinics, Faculty of Dentistry, The University of Hong Kong (Hong Kong); Horner, Keith [Dept. of Oral Radiology, University Dental Hospital of Manchester, Manchester (United Kingdom)

    2014-06-15

    The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

  10. An economic evaluation of maxillary implant overdentures based on six vs. four implants.

    Science.gov (United States)

    Listl, Stefan; Fischer, Leonhard; Giannakopoulos, Nikolaos Nikitas

    2014-08-18

    The purpose of the present study was to assess the value for money achieved by bar-retained implant overdentures based on six implants compared with four implants as treatment alternatives for the edentulous maxilla. A Markov decision tree model was constructed and populated with parameter estimates for implant and denture failure as well as patient-centred health outcomes as available from recent literature. The decision scenario was modelled within a ten year time horizon and relied on cost reimbursement regulations of the German health care system. The cost-effectiveness threshold was identified above which the six-implant solution is preferable over the four-implant solution. Uncertainties regarding input parameters were incorporated via one-way and probabilistic sensitivity analysis based on Monte-Carlo simulation. Within a base case scenario of average treatment complexity, the cost-effectiveness threshold was identified to be 17,564 € per year of denture satisfaction gained above of which the alternative with six implants is preferable over treatment including four implants. Sensitivity analysis yielded that, depending on the specification of model input parameters such as patients' denture satisfaction, the respective cost-effectiveness threshold varies substantially. The results of the present study suggest that bar-retained maxillary overdentures based on six implants provide better patient satisfaction than bar-retained overdentures based on four implants but are considerably more expensive. Final judgements about value for money require more comprehensive clinical evidence including patient-centred health outcomes.

  11. Effect of implant position, angulation, and attachment height on peri-implant bone stress associated with mandibular two-implant overdentures: a finite element analysis.

    Science.gov (United States)

    Hong, Hae Ryong; Pae, Ahran; Kim, Yooseok; Paek, Janghyun; Kim, Hyeong-Seob; Kwon, Kung-Rock

    2012-01-01

    The aim of this study was to analyze and compare the level and distribution of peri-implant bone stresses associated with mandibular two-implant overdentures with different implant positions. Mathematical models of mandibles and overdentures were designed using finite element analysis software. Two intraosseous implants and ball attachment systems were placed in the interforaminal region. The overdenture, which was supported by the two implants, was designed to withstand bilateral and unilateral vertical masticatory loads (total 100 N). In all, eight types of models, which differed according to assigned implant positions, height of attachments, and angulation, were tested: MI (model with implants positioned in the lateral incisor sites), MC (implants in canine sites), MP (implants in premolar sites), MI-Hi (greater height of attachments), MC-M (canine implants placed with mesial inclination), MC-D (canine implants placed with distal inclination), MC-B (canine implants placed with buccal inclination), and MC-L (canine implants placed with lingual inclination). Peri-implant bone stress levels associated with overdentures retained by lateral incisor implants resulted in the lowest stress levels and the highest efficiency in distributing peri-implant stress. MI-Hi showed increased stress levels and decreased efficiency in stress distribution. As the implants were inclined, stress levels increased and the efficiency of stress distribution decreased. Among the inclined models, MC-B showed the lowest stress level and best efficiency in stress distribution. The lowest stress and the best stability of implants in mandibular two-implant overdentures were obtained when implants were inserted in lateral incisor areas with shorter attachments and were placed parallel to the long axes of the teeth.

  12. Analysis techniques of charging damage studied on three different high-current ion implanters

    Science.gov (United States)

    Felch, S. B.; Larson, L. A.; Current, M. I.; Lindsey, D. W.

    1989-02-01

    One of the Greater Silicon Valley Implant Users' Group's recent activities has been to sponsor a round-robin on charging damage, where identical wafers were implanted on three different state-of-the-art, high-current ion implanters. The devices studied were thin-dielectric (250 Å SiO2), polysilicon-gate MOS capacitors isolated by thick field oxide. The three implanters involved were the Varian/Extrion 160XP, the Eaton/Nova 10-80, and the Applied Materials PI9000. Each implanter vendor was given 48 wafers to implant with 100 keV As+ ions at a dose of 1 × 1016 cm-2. Parameters that were varied include the beam current, electron flood gun current, and chamber pressure. The charge-to-breakdown, breakdown voltage, and leakage current of several devices before anneal have been measured. The results from these tests were inconclusive as to the physical mechanism of charging and as to the effectiveness of techniques to reduce its impact on devices. However, the methodology of this study is discussed in detail to aid in the planning of future experiments. Authors' industrial affiliations: S.B. Felch, Varian Research Center, 611 Hansen Way, Palo Alto, CA 94303, USA; L.A. Larson, National Semiconductor Corp., P.O. Box 58090, Santa Clara, CA 95052-8090, USA; M.I. Current, Applied Materials, 3050 Bowers Ave., Santa Clara, CA 95054, USA; D.W. Lindsey, Eaton/NOVA, 931 Benicia Ave, Sunnyvale, CA 94086, USA.

  13. Influence of different implant materials on the primary stability of orthodontic mini-implants.

    Science.gov (United States)

    Pan, Chin-Yun; Chou, Szu-Ting; Tseng, Yu-Chuan; Yang, Yi-Hsin; Wu, Chao-Yi; Lan, Ting-Hsun; Liu, Pao-Hsin; Chang, Hong-Po

    2012-12-01

    This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft(3) trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates(®) device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05). Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success. Copyright © 2012. Published by Elsevier B.V.

  14. Influence of different implant materials on the primary stability of orthodontic mini-implants

    Directory of Open Access Journals (Sweden)

    Chin-Yun Pan

    2012-12-01

    Full Text Available This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm. The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft3 trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates® device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05. Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success.

  15. Studying the issues in the additive manufacturing of dental implants by Electron Beam MeltingRTM (EBM)

    Science.gov (United States)

    Jamshidinia, Mahdi

    The ability of additive manufacturing (AM) processes to produce complex geometries is resulting in their rapid acceptance by a number of industries. This unique capability could be used for the optimization of the design of functional components that could find an application in different industries such as aerospace, automotive, energy, medical, and implants. However, there are still some challenges confronting this technology such as surface finish, residual stress, dimensional tolerance, processing speed, and anisotropy in microstructure and mechanical properties. Any of the mentioned issues could be influenced by the thermal history of a 3D printed component during the layer-by-layer manufacturing. Therefore, an understanding of the thermal cycling during the AM process is essential. In recent years, significant advances have been achieved in the design, manufacturing, and materials used for dental implants. However, there are still some differences between the natural tooth and a dental implant that might decrease patient satisfaction. One of the differences between the natural tooth and a dental implant is in its modulus of elasticity, which could result in an issue known as bone atrophy. The second important difference between a dental implant and a natural tooth is the fact that a natural tooth is surrounded by a periodontal ligament that allows the tooth to move in three directions. However, the periodontal ligament is destroyed during the extraction of a natural tooth. In the absence of the periodontal ligament, the biting force is directly transferred to the jawbone, resulting in discomfort for the patient. Also, the implant cannot be incorporated with the surrounding natural tooth and form a bridge. In this study, the application of a lattice structure for the manufacturing of a biocompatible dental implant is investigated. Three different lattice structures with different unit cell sizes were experimentally and numerically analyzed. The mechanical

  16. The relationship of theory of mind and executive functions in normal, deaf and cochlear-implanted children

    Directory of Open Access Journals (Sweden)

    Farideh Nazarzadeh

    2014-08-01

    Full Text Available Background and Aim : Theory of mind refers to the ability to understand the others have mental states that can be different from one's own mental states or facts. This study aimed to investigate the relationship of theory of mind and executive functions in normal hearing, deaf, and cochlear-implanted children.Methods: The study population consisted of normal, deaf and cochlear-implanted girl students in Mashhad city, Iran. Using random sampling, 30 children (10 normal, 10 deaf and 10 cochlear-implanted in age groups of 8-12 years old were selected. To measure the theoty of mind, theory of mind 38-item scale and to assess executive function, Coolidge neuropsychological and personality test was used. Research data were analyzed using the Spearman correlation coefficient, analysis of variance and Kruskal-Wallis tests.Results: There was a significant difference between the groups in the theory of mind and executive function subscales, organization, planning-decision-making, and inhibition. Between normal and deaf groups (p=0.01, as well as cochlear-implanted and deaf groups (p=0.01, there was significant difference in planning decision-making subscale. There was not any significant relationship between the theory of mind and executive functions generally or the theory of mind and executive function subscales in these three groups independently.Conclusion: Based on our findings, cochlear-implanted and deaf children have lower performance in theory of mind and executive function compared with normal hearing children.

  17. Cannabis sativa smoke inhalation decreases bone filling around titanium implants: a histomorphometric study in rats.

    Science.gov (United States)

    Nogueira-Filho, Getulio da R; Cadide, Tiago; Rosa, Bruno T; Neiva, Tiago G; Tunes, Roberto; Peruzzo, Daiane; Nociti, Francisco Humberto; César-Neto, João B

    2008-12-01

    Although the harmful effect of tobacco smoking on titanium implants has been documented, no studies have investigated the effects of cannabis sativa (marijuana) smoking. Thus, this study investigated whether marijuana smoke influences bone healing around titanium implants. Thirty Wistar rats were used. After anesthesia, the tibiae surface was exposed and 1 screw-shaped titanium implant was placed bilaterally. The animals were randomly assigned to one of the following groups: control (n = 15) and marijuana smoke inhalation (MSI) 8 min/d (n = 15). Urine samples were obtained to detect the presence of tetra-hidro-cannabinoid. After 60 days, the animals were killed. The degree of bone-to-implant contact and the bone area within the limits of the threads of the implant were measured in the cortical (zone A) and cancellous bone (zone B). Tetra-hidro-cannabinoid in urine was positive only for the rats of MSI group. Intergroup analysis did not indicate differences in zone A-cortical bone (P > 0.01), however, a negative effect of marijuana smoke (MSI group) was observed in zone B-cancellous bone for bone-to-implant contact and bone area (Student's t test, P smoke on bone healing may represent a new concern for implant success/failure.

  18. Structure of ion-implanted ceramics

    International Nuclear Information System (INIS)

    Naramoto, Hiroshi

    1983-01-01

    The variation of structure of LiF, MgO, Al 2 O 3 and TiO 2 accompanying annealing after ion implantation is explained. The analysis of structure is usually made by the perturbed gamma ray angular correlation, the internal electron Moessbauer method, or the ion scattering method. The results of analyses are discussed for alkali ion implantation, Fe-ion implantation, In-ion implantation, Au-ion implantation, Pt-ion implantation, Pb-ion implantation and transition metal ion implantation. The coupling of the implanted elements with lattice defects and matrix elements, and the compatibility between deposited elements and matrix crystal lattice were studied. The variation of physical properties due to ion implantation such as phase transition, volume change, the control of single crystal region, and the variation of hardness near surface were investigated, and the examples are presented. (Kato, T.)

  19. Studies of phase formation in CoSi2 buried layers fabricated using ion implantation

    International Nuclear Information System (INIS)

    Galaev, A.A.; Parkhomenko, Yu.N.; Podgornyi, D.A.; Shcherbachev, K.D.

    1998-01-01

    The processes of the formation of cobalt disilicide buried layers in silicon are studied under different conditions of implantation with Co. In particular, the effects of the implantation dose and the postimplantation annealing temperature on the state of the Co-implanted layer are considered. Two types of heteroepitaxial Si/CoSi 2 /Si structures are obtained with the conducting layers of thicknesses 70 and 90 nm buried at the depths 80 and 10 nm, respectively

  20. Untreated silicone breast implant rupture

    DEFF Research Database (Denmark)

    Hölmich, Lisbet R; Vejborg, Ilse M; Conrad, Carsten

    2004-01-01

    Implant rupture is a well-known complication of breast implant surgery that can pass unnoticed by both patient and physician. To date, no prospective study has addressed the possible health implications of silicone breast implant rupture. The aim of the present study was to evaluate whether untre...

  1. Clinical Evaluation of Small Diameter Straumann Implants in Partially Edentulous Patients: A 5-Year Retrospective Study

    Directory of Open Access Journals (Sweden)

    S. OZER

    2011-06-01

    Full Text Available Objective: The aim of the present study was to retrospectively evaluate small-diameter (3.3 mm Straumann® dental implants placed in the maxilla or the mandible over a period of 5 years in function.Materials and Methods: Twenty- eight partially edentulous patients received a total of 48 implants over a 5-year period. After the standard healing period (3 to 6 months, the implants were restored with single-tooth prostheses or fixed partial dentures. All patients were followed according to a strict maintenance program with regular recalls. The cumulative survival rates of implants were analyzed and prosthetic complications were assessed.Results: After 5 years of function, one single 10-mm-long implant in the maxillary premolar region was lost because of recurrent peri-implant infection in a female patient. Two single 10-mm-long maxillary implants placed in the posterior region were lost due to body fracture. The cumulative 5-year survival rate of the implants was 93.75 %. The most common prosthetic complication was loosening of the occlusal screw.Conclusion: Within the limited observation period and the number of patients included in this study, it may be concluded that the use of small-diameter implants appears to be predictable if clinical guidelines are followed and appropriate prosthetic restorations are provided. However, it should be noted that fatigue fracture may occur.

  2. Maxillary implant-supported overdentures opposed by (partial) natural dentitions : A 5-year prospective case series study

    NARCIS (Netherlands)

    Boven, G. C.; Slot, J. W. A.; Raghoebar, G. M.; Vissink, A.; Meijer, H. J. A.

    2017-01-01

    The aim of this study was to assess the 5-year treatment outcome of maxillary implant-retained overdentures opposed by natural antagonistic teeth. Fifty consecutive patients received maxillary overdentures supported by six dental implants. Implants were placed in the anterior region, if enough bone

  3. Short dental implants versus standard dental implants placed in the posterior jaws: A systematic review and meta-analysis.

    Science.gov (United States)

    Lemos, Cleidiel Aparecido Araujo; Ferro-Alves, Marcio Luiz; Okamoto, Roberta; Mendonça, Marcos Rogério; Pellizzer, Eduardo Piza

    2016-04-01

    The purpose of the present systematic review and meta-analysis was to compare short implants (equal or less than 8mm) versus standard implants (larger than 8mm) placed in posterior regions of maxilla and mandible, evaluating survival rates of implants, marginal bone loss, complications and prosthesis failures. This review has been registered at PROSPERO under the number CRD42015016588. Main search terms were used in combination: dental implant, short implant, short dental implants, short dental implants posterior, short dental implants maxilla, and short dental implants mandible. An electronic search for data published up until September/2015 was undertaken using the PubMed/Medline, Embase and The Cochrane Library databases. Eligibility criteria included clinical human studies, randomized controlled trials and/or prospective studies, which evaluated short implants in comparison to standard implants in the same study. The search identified 1460 references, after inclusion criteria 13 studies were assessed for eligibility. A total of 1269 patients, who had received a total of 2631 dental implants. The results showed that there was no significant difference of implants survival (P=.24; RR:1.35; CI: 0.82-2.22), marginal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00), complications (P=.08; RR:0.54; CI: 0.27-1.09) and prosthesis failures (P=.92; RR:0.96; CI: 0.44-2.09). Short implants are considered a predictable treatment for posterior jaws. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks to failures compared to standard implants. Short implants are frequently placed in the posterior area in order to avoid complementary surgical procedures. However, clinicians need to be aware that short implants with length less than 8mm present greater risk of failures. Copyright © 2016. Published by Elsevier Ltd.

  4. Cancer among Scandinavian women with cosmetic breast implants: a pooled long-term follow-up study.

    Science.gov (United States)

    Lipworth, Loren; Tarone, Robert E; Friis, Søren; Ye, Weimin; Olsen, Jørgen H; Nyren, Olof; McLaughlin, Joseph K

    2009-01-15

    No increased risks of specific types of cancer following breast implantation have been consistently reported, but data on risk beyond 15 years are limited. We have pooled the results of 2 nationwide cohort studies of 3,486 Swedish and 2,736 Danish women who underwent cosmetic breast implantation between 1965 and 1993. Cancer incidence through 2002 was ascertained through nationwide cancer registries. Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated to compare cancer incidence among women with implants with women in the general population. Mean duration of follow up was 16.6 years (range 0.1-37.8 years). Over 50% of women were followed for 15 years or more after breast implantation and 13.3% for at least 25 years. There was a reduced incidence of breast cancer (SIR=0.73; 95% CI 0.58-0.90), whereas lung cancer was above expectation (SIR=1.64; 95% CI 1.10-2.36). The increased risk of lung cancer is expected due to the high prevalence of smoking among the women with implants in our study. With respect to other site-specific cancers, no significantly increased or decreased SIR was observed. This study, which includes women followed for almost 4 decades, represents the longest follow up of women with cosmetic breast implants to date. The results provide no evidence of an association between breast implants and any type of cancer. Copyright (c) 2008 Wiley-Liss, Inc.

  5. Comparison of implant component fractures in external and internal type: A 12-year retrospective study.

    Science.gov (United States)

    Yi, Yuseung; Koak, Jai-Young; Kim, Seong-Kyun; Lee, Shin-Jae; Heo, Seong-Joo

    2018-04-01

    The aim of this study was to compare the fracture of implant component behavior of external and internal type of implants to suggest directions for successful implant treatment. Data were collected from the clinical records of all patients who received WARANTEC implants at Seoul National University Dental Hospital from February 2002 to January 2014 for 12 years. Total number of implants was 1,289 and an average of 3.2 implants was installed per patient. Information about abutment connection type, implant locations, platform sizes was collected with presence of implant component fractures and their managements. SPSS statistics software (version 24.0, IBM) was used for the statistical analysis. Overall fracture was significantly more frequent in internal type. The most frequently fractured component was abutment in internal type implants, and screw fracture occurred most frequently in external type. Analyzing by fractured components, screw fracture was the most frequent in the maxillary anterior region and the most abutment fracture occurred in the maxillary posterior region and screw fractures occurred more frequently in NP (narrow platform) and abutment fractures occurred more frequently in RP (regular platform). In external type, screw fracture occurred most frequently, especially in the maxillary anterior region, and in internal type, abutment fracture occurred frequently in the posterior region. placement of an external type implant rather than an internal type is recommended for the posterior region where abutment fractures frequently occur.

  6. Random spectrum loading of dental implants: An alternative approach to functional performance assessment.

    Science.gov (United States)

    Shemtov-Yona, K; Rittel, D

    2016-09-01

    The fatigue performance of dental implants is usually assessed on the basis of cyclic S/N curves. This neither provides information on the anticipated service performance of the implant, nor does it allow for detailed comparisons between implants unless a thorough statistical analysis is performed, of the kind not currently required by certification standards. The notion of endurance limit is deemed to be of limited applicability, given unavoidable stress concentrations and random load excursions, that all characterize dental implants and their service conditions. We propose a completely different approach, based on random spectrum loading, as long used in aeronautical design. The implant is randomly loaded by a sequence of loads encompassing all load levels it would endure during its service life. This approach provides a quantitative and comparable estimate of its performance in terms of lifetime, based on the very fact that the implant will fracture sooner or later, instead of defining a fatigue endurance limit of limited practical application. Five commercial monolithic Ti-6Al-4V implants were tested under cyclic, and another 5 under spectrum loading conditions, at room temperature and dry air. The failure modes and fracture planes were identical for all implants. The approach is discussed, including its potential applications, for systematic, straightforward and reliable comparisons of various implant designs and environments, without the need for cumbersome statistical analyses. It is believed that spectrum loading can be considered for the generation of new standardization procedures and design applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Magnetic resonance imaging investigation of the bone conduction implant - a pilot study at 1.5 Tesla.

    Science.gov (United States)

    Jansson, Karl-Johan Fredén; Håkansson, Bo; Reinfeldt, Sabine; Rigato, Cristina; Eeg-Olofsson, Måns

    2015-01-01

    The objective of this pilot study was to investigate if an active bone conduction implant (BCI) used in an ongoing clinical study withstands magnetic resonance imaging (MRI) of 1.5 Tesla. In particular, the MRI effects on maximum power output (MPO), total harmonic distortion (THD), and demagnetization were investigated. Implant activation and image artifacts were also evaluated. One implant was placed on the head of a test person at the position corresponding to the normal position of an implanted BCI and applied with a static pressure using a bandage and scanned in a 1.5 Tesla MRI camera. Scanning was performed both with and without the implant, in three orthogonal planes, and for one spin-echo and one gradient-echo pulse sequence. Implant functionality was verified in-between the scans using an audio processor programmed to generate a sequence of tones when attached to the implant. Objective verification was also carried out by measuring MPO and THD on a skull simulator as well as retention force, before and after MRI. It was found that the exposure of 1.5 Tesla MRI only had a minor effect on the MPO, ie, it decreased over all frequencies with an average of 1.1±2.1 dB. The THD remained unchanged above 300 Hz and was increased only at lower frequencies. The retention magnet was demagnetized by 5%. The maximum image artifacts reached a distance of 9 and 10 cm from the implant in the coronal plane for the spin-echo and the gradient-echo sequence, respectively. The test person reported no MRI induced sound from the implant. This pilot study indicates that the present BCI may withstand 1.5 Tesla MRI with only minor effects on its performance. No MRI induced sound was reported, but the head image was highly distorted near the implant.

  8. Two-stage implant systems.

    Science.gov (United States)

    Fritz, M E

    1999-06-01

    Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of

  9. Esthetic Outcomes of Immediately Loaded Locking Taper Implants in the Anterior Maxilla: A Case Series Study.

    Science.gov (United States)

    Lombardo, Giorgio; Corrocher, Giovanni; Pighi, Jacopo; Mascellaro, Anna; Marincola, Mauro; Nocini, Per Francesco

    2016-06-01

    The purpose of this study was to evaluate the esthetic outcome of single-tooth locking taper connection implants placed in the anterior maxilla following a postextractive nonfunctional loading protocol. This preliminary clinical study involving 16 patients evaluated the results of 21 implants placed in areas with high esthetic value. For each implant the pink esthetic score, white esthetic score, cumulative survival rate, and health status of peri-implant tissues were evaluated. The cumulative survival rate was 100% 2 years after prosthetic loading, and the mean total pink esthetic score/white esthetic score was 16.9 ± 1.14 on a maximum value of 20. There was excellent plaque control in all patients, and inflammation indices were within the norm. Within the limits of this study, this immediate nonfunctional loading protocol seems to be a successful procedure esthetically and for the maintenance of peri-implant soft tissues.

  10. Long-term retrospective study of implants placed after sinus floor augmentation with fresh-frozen homologous block

    Directory of Open Access Journals (Sweden)

    Livingstom Rubens Sousa Rocha

    2017-01-01

    Full Text Available Aim: The aim of this study was to analyze and follow-up implants placed in the posterior maxillary regions previously grafted with homologous bone. Materials and Methods: Forty-one grafts with homologous bone blocks were performed in maxillary sinuses, and 121 implants were placed in premolar and molar regions approximately 6 months after the grafts. Patients were followed up for periods varying from 12 to 124 months after rehabilitation. Results: The results showed two implant failures, for a 98.3% success rate during the follow-up period. Discussion: The implants placed had an average torque of 40 N-cm, regardless of the, design, diameter, and length of the implants used. Conclusion: After following up on the implants placed in this study, we concluded that those placed in regions of the maxillary sinuses previously grafted with homologous bone blocks had high long-term success rates and met the functional masticatory requirements.

  11. Implant-supported removable partial dentures in the mandible : A 3-16 year retrospective study

    NARCIS (Netherlands)

    Jensen, Charlotte; Meijer, Henny J A; Raghoebar, Gerry M; Kerdijk, Wouter; Cune, Marco S

    PURPOSE: The purpose of this retrospective study was to assess performance, together with biological and technical complications, of implant-supported removable partial dentures (ISRPD) in mandibular Kennedy class I situations with implants placed in the anterior or posterior position. METHODS: 23

  12. Implant-supported removable partial dentures in the mandible : A 3-16 year retrospective study

    NARCIS (Netherlands)

    Jensen, Charlotte; Meijer, Henny J. A.; Raghoebar, Gerry M.; Kerdijk, Wouter; Cune, Marco S.

    Purpose: The purpose of this retrospective study was to assess performance, together with biological and technical complications, of implant-supported removable partial dentures (ISRPD) in mandibular Kennedy class I situations with implants placed in the anterior or posterior position. Methods: 23

  13. Implantation of β-emitters on biomedical implants: 32 P isotropic ion implantation using a coaxial plasma reactor

    International Nuclear Information System (INIS)

    Fortin, M.A.; Paynter, R.W.; Sarkissian, A.; Stansfield, B.L.; Terreault, B.; Dufresne, V.

    2003-01-01

    The development of endovascular brachytherapy and the treatment of certain types of cancers (liver, lung, prostate) often require the use of beta-emitters, sometimes in the form of radioisotope-implanted devices. Among the most commonly used isotopes figures 32 P, a pure beta-emitter (maximum energy: 1.7 MeV), of which the path in biological tissues is of a few cm, restricting the impact of electron bombardment to the immediate environment of the implant. Several techniques and processes have been tried to elaborate surfaces and devices showing strongly bonded, or implanted 32 P. Anodizing, vapor phase deposition, grafting of oligonucleotides, as well as ion implantation processes have been investigated by several research groups as methods to implant beta-radioisotopes into surfaces. A coaxial plasma reactor was developed at INRS to implant radioisotopes into cylindrical metallic objects, such as coronary stents commonly used in angioplasty procedures. The dispersion of 32 P atoms on the interior surfaces of the chamber can be investigated using radiographs, contributing to image the plasma ion transport mechanisms that guide the efficiency of the implantation procedure. The amount of radioactivity on the wall liner, on the internal components, and on the biomedical implants are quantified using a surface barrier detector. A comparative study establishes a relationship between the gray scale of the radiographs, and dose measurements. A program was developed to convert the digitized images into maps showing surface dose density in mCi/cm 2 . An integration process allows the quantification of the doses on the walls and components of the reactor. Finally, the resulting integral of the 32 P dose is correlated to the initial amount of radioactivity inserted inside the implanter before the dismantling procedure. This method could be introduced as a fast and reliable way to test, qualify and assess the amount of radioactivity present on the as-produced implants

  14. Qualitative case studies of five cochlear implant recipients' experience with music.

    Science.gov (United States)

    Bartel, Lee R; Greenberg, Simon; Friesen, Lendra M; Ostroff, Jodi; Bodmer, Daniel; Shipp, David; Chen, Joseph M

    2011-02-01

    Cochlear implantation has revolutionized the management of those who suffer from severe-to-profound hearing loss because many patients now achieve excellent speech understanding with objective testing. Nevertheless, speech understanding in noisy conditions and music appreciation remain significant challenges to cochlear implant (CI) users. Music appreciation is an extremely complex experience that is difficult to quantify through a conventional outcome study. This paper aims at documenting the experience of five CI patients with regard to music appreciation using qualitative techniques. This information was obtained through a semi-structured interview process. The interviews were then transcribed and analysed using a constant comparative method of qualitative description. The results together with medical case records were used to identify emerging themes. The common themes that evolved were: musical background, the experience of receiving the implant, current experience with music, attention, musical prediction ability, internal hearing, hedonic vs. critical listening, determination, and timbre perception. By documenting their experiences in this manner, novel insights into the patient perspective are provided that are unique to the literature. These descriptions will aid clinicians and researchers who work in the area of cochlear implantation to better understand the needs of their patients.

  15. Accuracy of various impression materials and methods for two implant systems: An effect size study.

    Science.gov (United States)

    Schmidt, Alexander; Häussling, Teresa; Rehmann, Peter; Schaaf, Heidrun; Wöstmann, Bernd

    2018-04-01

    An accurate impression is required for implant treatment. The aim of this in-vitro study was to determine the effect size of the impression material/method, implant system and implant angulation on impression transfer precision. An upper jaw model with three BEGO and three Straumann implants (angulations 0°, 15°, 20°) in the left and right maxilla was used as a reference model. One polyether (Impregum Penta) and two polyvinyl siloxanes (Flexitime Monophase/Aquasil Ultra Monophase) were examined with two impression techniques (open and closed tray). A total of 60 impressions were made. A coordinate measurement machine was used to measure the target variables for 3D-shift, implant axis inclination and implant axis rotation. All the data were subjected to a four-way ANOVA. The effect size (partial eta-squared [η 2 P ]) was reported. The impression material had a significant influence on the 3D shift and the implant axis inclination deviation (p-values=.000), and both factors had very large effect sizes (3D-shift [η 2 P ]=.599; implant axis inclination [η 2 P ]=.298). Impressions made with polyvinyl siloxane exhibited the highest transfer precision. When the angulation of the implants was larger, more deviations occurred for the implant axis rotational deviation. The implant systems and impression methods showed partially significant variations (p-values=.001-.639) but only very small effect sizes (η 2 P =.001-.031). The impression material had the greatest effect size on accuracy in terms of the 3D shift and the implant axis inclination. For multiunit restorations with disparallel implants, polyvinyl siloxane materials should be considered. In addition, the effect size of a multivariate investigation should be reported. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  16. Evaluation of single-tooth implants in the second molar region: a 5-year life-table analysis of a retrospective study.

    Science.gov (United States)

    Koo, Ki-Tae; Wikesjö, Ulf M E; Park, Jang-Yeol; Kim, Tae-Il; Seol, Yang-Jo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung; Lee, Yong-Moo

    2010-09-01

    To our knowledge, no study has evaluated the success or survival rate of single-tooth implants that replaced missing maxillary and mandibular second molars. The purpose of the present study was to evaluate the 1- to 5-year cumulative survival rate (CSR) for single-tooth implants placed in the second molar region and the effects of associated factors. Four hundred eighty-nine patients (298 males and 191 females; age range: 23 to 91 years; mean age: 47 years) who were admitted to the Seoul National University Dental Hospital between March 2003 and July 2008 and treated with single-tooth implants in the second molar region (227 maxillary implants and 294 mandibular implants; total: 521 implants) were included in the study. Thirty-two subjects received two implants each. A 1- to 5-year CSR was calculated using a life-table analysis. A comparison of CSRs between maxillary versus mandibular implants, one-stage versus two-stage implants, short (10 mm) implants, and standard-diameter (or=5.0 mm) implants was performed using Wilcoxon (Gehan) statistics. P CSR was 95.1%. There were no statistically significant differences in CSRs between implants placed in maxillas and mandibles (96.3% versus 94.9%, respectively; P = 0.084), one- and two-stage implants (95.6% versus 94.7%, respectively; P = 0.267), short and long implants (100% versus 95.1%, respectively; P = 0.582), and standard- and wide-diameter implants (93.8% versus 96.8%, respectively; P = 0.065). Within the limitations of the study, the placement of single-tooth implants in the second molar region was an effective and reliable treatment modality. Also, associated factors such as implant diameter, length, and location (the maxilla versus the mandible) may not have an impact on the long-term success of implants.

  17. Peri-Implant Endosseous Healing Properties of Dual Acid-Etched Mini-Implants with a Nanometer-Sized Deposition of CaP : A Histological and Histomorphometric Human Study

    NARCIS (Netherlands)

    Telleman, Gerdien; Albrektsson, Tomas; Hoffman, Maria; Johansson, Carina B.; Vissink, Arjan; Meijer, Henny J. A.; Raghoebar, Gerry M.

    2010-01-01

    Purpose: The aim of this histological and histomorphometric study was to compare the early peri-implant endosseous healing properties of a dual acid-etched (DAE) surface (Osseotite (R), Implant Innovations Inc., Palm Beach Gardens, FL, USA) with a DAE surface modified with nanometer-sized calcium

  18. Fracture strength of zirconia implant abutments on narrow diameter implants with internal and external implant abutment connections: A study on the titanium resin base concept.

    Science.gov (United States)

    Sailer, Irena; Asgeirsson, Asgeir G; Thoma, Daniel S; Fehmer, Vincent; Aspelund, Thor; Özcan, Mutlu; Pjetursson, Bjarni E

    2018-04-01

    There is limited knowledge regarding the strength of zirconia abutments with internal and external implant abutment connections and zirconia abutments supported by a titanium resin base (Variobase, Straumann) for narrow diameter implants. To compare the fracture strength of narrow diameter abutments with different types of implant abutment connections after chewing simulation. Hundred and twenty identical customized abutments with different materials and implant abutment connections were fabricated for five groups: 1-piece zirconia abutment with internal connection (T1, Cares-abutment-Straumann BL-NC implant, Straumann Switzerland), 1-piece zirconia abutment with external hex connection (T2, Procera abutment-Branemark NP implant, Nobel Biocare, Sweden), 2-piece zirconia abutments with metallic insert for internal connection (T3, Procera abutment-Replace NP implant, Nobel Biocare), 2-piece zirconia abutment on titanium resin base (T4, LavaPlus abutment-VarioBase-Straumann BL-NC implant, 3M ESPE, Germany) and 1-piece titanium abutment with internal connection (C, Cares-abutment-Straumann BL-NC implant, Straumann, Switzerland). All implants had a narrow diameter ranging from 3.3 to 3.5 mm. Sixty un-restored abutments and 60 abutments restored with glass-ceramic crowns were tested. Mean bending moments were compared using ANOVA with p-values adjusted for multiple comparisons using Tukey's procedure. The mean bending moments were 521 ± 33 Ncm (T4), 404 ± 36 Ncm (C), 311 ± 106 Ncm (T1) 265 ± 22 Ncm (T3) and 225 ± 29 (T2) for un-restored abutments and 278 ± 84 Ncm (T4), 302 ± 170 Ncm (C), 190 ± 55 Ncm (T1) 80 ± 102 Ncm (T3) and 125 ± 57 (T2) for restored abutments. For un-restored abutments, C and T4 had similar mean bending moments, significantly higher than those of the three other groups (p internal connection had higher bending moments than zirconia abutments with external connection (T2) (p internal connected zirconia

  19. Study and realisation of plane optical waveguides in amorphous silica by ion implantation

    International Nuclear Information System (INIS)

    Moutonnet, Danielle

    1974-01-01

    Within the framework of the replacement of radio-electric waves by light waves as support of information transmission in telecommunications, this research thesis addresses the use of ion implantation for the development of small waveguides with low losses. The author first describes how such waveguides can be characterised by studying the propagation of an electromagnetic wave in a plane waveguide, and the different ways to introduce energy in these waveguides. Then, she discusses how the obtained results can be used to determine the main parameters of an optical waveguide, or more generally of a thin transparent layer for a chosen wavelength. In the second part, the author reports the application of this general method to the case of guides obtained by ion implantation. She notably identifies the possibilities of ion implantation as technological tool to develop waveguides, and discusses how the performed experiments allow a better understanding of physical mechanisms occurring during implantation. In this second part, she recalls generally admitted theories about ion implantation, describes experiment principles (implantation of oxygen or nitrogen ions into amorphous silica followed by annealing) and discusses the obtained results (increase of the refraction index, i.e. of the guiding effect, stronger for oxygen than for nitrogen) [fr

  20. The Effect of Tissue Entrapment on Screw Loosening at the Implant/Abutment Interface of External- and Internal-Connection Implants: An In Vitro Study.

    Science.gov (United States)

    Zeno, Helios A; Buitrago, Renan L; Sternberger, Sidney S; Patt, Marisa E; Tovar, Nick; Coelho, Paulo; Kurtz, Kenneth S; Tuminelli, Frank J

    2016-04-01

    To compare the removal of torque values of machined implant abutment connections (internal and external) with and without soft tissue entrapment using an in vitro model. Thirty external- and 30 internal-connection implants were embedded in urethane dimethacrylate. Porcine tissue was prepared and measured to thicknesses of 0.5 and 1.0 mm. Six groups (n = 10) were studied: External- and internal-connection implants with no tissue (control), 0.5, and 1.0 mm of tissue were entrapped at the implant/abutment interface. Abutments were inserted to 20 Ncm for all six groups. Insertion torque values were recorded using a digital torque gauge. All groups were then immersed in 1 M NaOH for 48 hours to dissolve tissue. Subsequent reverse torque measurements were recorded. Mean and standard deviation were determined for each group, and one-way ANOVA and Bonferroni test were used for statistical analysis. All 60 specimens achieved a 20-Ncm insertion torque, despite tissue entrapment. Reverse torque measurements for external connection displayed a statistically significant difference (p internal-connection groups. In all specimens, tissue did not completely dissolve after 48 hours. External-connection implants were significantly affected by tissue entrapment; the thicker the tissue, the lower the reverse torque values noted. Internal-connection implants were less affected by tissue entrapment. © 2015 by the American College of Prosthodontists.

  1. Immediate loading implants with mandibular overdenture: a 48-month prospective follow-up study

    Directory of Open Access Journals (Sweden)

    Karla ZANCOPE

    2014-08-01

    Full Text Available The aim of this prospective clinical study was to evaluate patient rehabilitation with two immediately loaded implants and bar-retained mandibular overdentures after 48 months of follow-up. Twenty patients were treated with two implants each; of these, 17 patients were re-evaluated for comparison. Gender, age, plaque index, gingival inflammation, keratinized mucosa, probing depth, bleeding, and implant loss data were recorded, and periapical radiographs were obtained for measurement of marginal bone loss. The results were statistically analyzed with one-way analysis of variance (ANOVA followed by Student’s t-test and Pearson’s correlation test. To compare the data at baseline and after 48 months, a Wilcoxon Signed Rank Test was performed (α = 0.05. One implant failed (2.9% during the first year and was replaced. A total of 35 implants were evaluated. Bone loss values were 0.52–2.89 mm (mean, 1.46 mm. Probing depth was 1.75–3.75 mm (mean, 2.22 mm. Correlations were found between bone loss and plaque index and between bone loss and gender, but bone loss did not correlate with gingival inflammation, keratinized mucosa, probing depth, or age. The overall survival rate of the implants was 97.1%. Based on these results, the use of two immediately loaded splinted interforaminal implants to retain an overdenture with a bar attachment is a clinically viable option with a high survival rate.

  2. Effects of recoil-implanted oxygen on depth profiles of defects and annealing processes in P{sup +}-implanted Si studied using monoenergetic positron beams

    Energy Technology Data Exchange (ETDEWEB)

    Uedono, Akira; Moriya, Tsuyoshi; Tanigawa, Shoichiro [Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science; Kitano, Tomohisa; Watanabe, Masahito; Kawano, Takao; Suzuki, Ryoichi; Ohdaira, Toshiyuki; Mikado, Tomohisa

    1996-04-01

    Effects of oxygen atoms recoiled from SiO{sub 2} films on depth profiles of defects and annealing processes in P{sup +}-implanted Si were studied using monoenergetic positron beams. For an epitaxial Si specimen, the depth profile of defects was found to be shifted toward the surface by recoil implantation of oxygen atoms. This was attributed to the formation of vacancy-oxygen complexes and a resultant decrease in the diffusion length of vacancy-type defects. The recoiled oxygen atoms stabilized amorphous regions introduced by P{sup +}-implantation, and the annealing of these regions was observed after rapid thermal annealing (RTA) at 700degC. For a Czochralski-grown Si specimen fabricated by through-oxide implantation, the recoiled oxygen atoms introduced interstitial-type defects upon RTA below the SiO{sub 2}/Si interface, and such defects were dissociated by annealing at 1000degC. (author)

  3. Preparation and biocompatibility study of in situ forming polymer implants in rat brains.

    Science.gov (United States)

    Nasongkla, Norased; Boongird, Atthaporn; Hongeng, Suradej; Manaspon, Chawan; Larbcharoensub, Noppadol

    2012-02-01

    We describe the development of polymer implants that were designed to solidify once injected into rat brains. These implants comprised of glycofurol and copolymers of D: ,L: -lactide (LA), ε-caprolactone and poly(ethylene glycol) (PLECs). Scanning electron microscopy (SEM) and gel permeation chromatography (GPC) showed that the extent of implant degradation was increased with LA: content in copolymers. SEM analysis revealed the formation of porosity on implant surface as the degradation proceeds. PLEC with 19.3% mole of LA: was chosen to inject in rat brains at the volume of 10, 25 and 40 μl. Body weights, hematological and histopathological data of rats treated with implants were evaluated on day 3, 6, 14, 30 and 45 after the injection. Polymer solution at the injection volume of 10 μl were tolerated relatively well compared to those of 25 and 40 μl as confirmed by higher body weight and healing action (fibrosis tissue) 30 days after treatment. The results from this study suggest a possible application as drug delivery systems that can bypass the blood brain barrier.

  4. [Clinical application of individualized three-dimensional printing implant template in multi-tooth dental implantation].

    Science.gov (United States)

    Wang, Lie; Chen, Zhi-Yuan; Liu, Rong; Zeng, Hao

    2017-08-01

    To study the value and satisfaction of three-dimensional printing implant template and conventional implant template in multi-tooth dental implantation. Thirty cases (83 teeth) with missing teeth needing to be implanted were randomly divided into conventional implant template group (CIT group, 15 cases, 42 teeth) and 3D printing implant template group (TDPIT group, 15 cases, 41 teeth). Patients in CIT group were operated by using conventional implant template, while patients in TDPIT group were operated by using three-dimensional printing implant template. The differences of implant neck and tip deviation, implant angle deviation and angle satisfaction between the two groups were compared. The difference of probing depth and bone resorption of implant were compared 1 year after operation between the two groups. The difference of success rate and satisfaction of dental implantation were compared 1 year after operation between the two groups. SPSS19.0 software package was used for statistical analysis. The deviation direction of the neck and the tip in disto-mesial, bucco-palatal, vertical direction and angle of implants in disto-mesial and bucco-palatal direction in TDPIT group were significantly lower than in CIT group (P0.05). The difference of the cumulative success rate in dental implantation at 3 months and 6 months between the two groups were not significant (P>0.05), but the cumulative success rate of TDPIT group was significantly higher than CIT group at 9 months and 1 year (90.48% vs 100%,P=0.043). The patients' satisfaction rate of dental implantation in TDPIT group was significantly higher than in CIT group (86.67% vs 53.33%, P=0.046). Using three-dimensional printing implant template can obtain better accuracy of implant, higher implant success rate and better patients' satisfaction than using conventional implant template. It is suitable for clinical application.

  5. 3D Printing/Additive Manufacturing Single Titanium Dental Implants: A Prospective Multicenter Study with 3 Years of Follow-Up.

    Science.gov (United States)

    Tunchel, Samy; Blay, Alberto; Kolerman, Roni; Mijiritsky, Eitan; Shibli, Jamil Awad

    2016-01-01

    This prospective 3-year follow-up clinical study evaluated the survival and success rates of 3DP/AM titanium dental implants to support single implant-supported restorations. After 3 years of loading, clinical, radiographic, and prosthetic parameters were assessed; the implant survival and the implant-crown success were evaluated. Eighty-two patients (44 males, 38 females; age range 26-67 years) were enrolled in the present study. A total of 110 3DP/AM titanium dental implants (65 maxilla, 45 mandible) were installed: 75 in healed alveolar ridges and 35 in postextraction sockets. The prosthetic restorations included 110 single crowns (SCs). After 3 years of loading, six implants failed, for an overall implant survival rate of 94.5%; among the 104 surviving implant-supported restorations, 6 showed complications and were therefore considered unsuccessful, for an implant-crown success of 94.3%. The mean distance between the implant shoulder and the first visible bone-implant contact was 0.75 mm (±0.32) and 0.89 (±0.45) after 1 and 3 years of loading, respectively. 3DP/AM titanium dental implants seem to represent a successful clinical option for the rehabilitation of single-tooth gaps in both jaws, at least until 3-year period. Further, long-term clinical studies are needed to confirm the present results.

  6. 3D Printing/Additive Manufacturing Single Titanium Dental Implants: A Prospective Multicenter Study with 3 Years of Follow-Up

    Directory of Open Access Journals (Sweden)

    Samy Tunchel

    2016-01-01

    Full Text Available This prospective 3-year follow-up clinical study evaluated the survival and success rates of 3DP/AM titanium dental implants to support single implant-supported restorations. After 3 years of loading, clinical, radiographic, and prosthetic parameters were assessed; the implant survival and the implant-crown success were evaluated. Eighty-two patients (44 males, 38 females; age range 26–67 years were enrolled in the present study. A total of 110 3DP/AM titanium dental implants (65 maxilla, 45 mandible were installed: 75 in healed alveolar ridges and 35 in postextraction sockets. The prosthetic restorations included 110 single crowns (SCs. After 3 years of loading, six implants failed, for an overall implant survival rate of 94.5%; among the 104 surviving implant-supported restorations, 6 showed complications and were therefore considered unsuccessful, for an implant-crown success of 94.3%. The mean distance between the implant shoulder and the first visible bone-implant contact was 0.75 mm (±0.32 and 0.89 (±0.45 after 1 and 3 years of loading, respectively. 3DP/AM titanium dental implants seem to represent a successful clinical option for the rehabilitation of single-tooth gaps in both jaws, at least until 3-year period. Further, long-term clinical studies are needed to confirm the present results.

  7. The effect of number and distribution of unsplinted maxillary implants on the load transfer in implant-retained maxillary overdentures: an in vitro study.

    Science.gov (United States)

    Damghani, Sahar; Masri, Radi; Driscoll, Carl F; Romberg, Elaine

    2012-06-01

    There is little information as to how the number and distribution of implants affect the amount of load transmitted to the palate in implant-retained maxillary overdentures. The purpose of this study was to evaluate the effect of the number and distribution of dental implants on the load transmitted to the palate. Eight implant analogues were placed in a replica of an average sized edentulous maxilla corresponding to the position of canines, first and second premolars, and first molars. The anteroposterior distance between the centers of implants in each quadrant was 8 mm. Fifteen denture bases were fabricated to fit the edentulous maxilla analogue. The denture bases were attached to the oral analogue using 6 different configurations of attachments (6 groups): Either no Locator attachments were used (control group), or the 2 most anterior attachments were attached, or 4 implants were engaged with a distance of 8, 16, or 24 mm between the centers of implants on left and right side, and finally, when all 8 attachments were activated. A force-measuring sensor was used to measure the force transmitted to the palate when a static force of 245 N was applied on the occlusal rims of the denture bases. Data (Newtons) were analyzed using 1-way ANOVA and Tukey's HSD test α=.05). The mean (SD) amount of force measured on the palate when the overdentures were supported by 4 Locator attachments; [49.84 (26.52) at 8 mm spacing], [24.42 (15.05) at 16 mm spacing], [35.66 (22.94) at 24 mm spacing] was significantly lower than when no attachments [90.98 (20.20), control], or when 2 Locator attachments were used [76.07 (27.63)] (Poverdentures were supported by 8 Locator attachments, the force measured on the palate [20.67(16.06) N] was significantly lower than that for the control group (Poverdentures supported by 2 Locator attachments (Poverdentures supported by 4 Locator attachments when the distance between the anterior and posterior implants was 8 mm P=.006). The distribution of

  8. Comparison of external and internal implant-abutment connections for implant supported prostheses. A systematic review and meta-analysis.

    Science.gov (United States)

    Lemos, Cleidiel Aparecido Araujo; Verri, Fellippo Ramos; Bonfante, Estevam Augusto; Santiago Júnior, Joel Ferreira; Pellizzer, Eduardo Piza

    2018-03-01

    The systematic review and meta-analysis aimed to answer the PICO question: "Do patients that received external connection implants show similar marginal bone loss, implant survival and complication rates as internal connection implants?". Meta-analyses of marginal bone loss, survival rates of implants and complications rates were performed for the included studies. Study eligibility criteria included (1) randomized controlled trials (RCTs) and/or prospective, (2) studies with at least 10 patients, (3) direct comparison between connection types and (4) publications in English language. The Cochrane risk of bias tool was used to assess the quality and risk of bias in RCTs, while Newcastle-Ottawa scale was used for non-RCTs. A comprehensive search strategy was designed to identify published studies on PubMed/MEDLINE, Scopus, and The Cochrane Library databases up to October 2017. The search identified 661 references. Eleven studies (seven RCTs and four prospective studies) were included, with a total of 530 patients (mean age, 53.93 years), who had received a total of 1089 implants (461 external-connection and 628 internal-connection implants). The internal-connection implants exhibited lower marginal bone loss than external-connection implants (PInternal connections had lower marginal bone loss when compared to external connections. However, the implant-abutment connection had no influence on the implant's survival and complication rates. Based on the GRADE approach the evidence was classified as very low to moderate due to the study design, inconsistency, and publication bias. Thus, future research is highly encouraged. Internal connection implants should be preferred over external connection implants, especially when different risk factors that may contribute to increased marginal bone loss are present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Dental Implant Surrounding Marginal Bone Level Evaluation: Platform Switching versus Platform Matching—One-Year Retrospective Study

    Directory of Open Access Journals (Sweden)

    Eisner Salamanca

    2017-01-01

    Full Text Available The benefits and feasibility of platform switching have been discussed in several studies, reporting lesser crestal bone loss in platform-switched implants than in platform-matched implants. Objective. The aim of the present study was to observe the changes in vertical and horizontal marginal bone levels in platform-switched and platform-matched dental implants. Materials and Methods. 51 patients received 60 dental implants in the present study over a 1-year period. Measurement was performed between the implant shoulder and the most apical and horizontal marginal defect by periapical radiographs to examine the changes of peri-implant alveolar bone before and 12 months after prosthodontic restoration delivery. Results. These marginal bone measurements showed a bone gain of 0.23±0.58 mm in the vertical gap and 0.22±0.53 mm in the horizontal gap of platform matching, while in platform switching a bone gain of 0.93±1 mm (P<0.05 in the vertical gap and 0.50±0.56 mm in the horizontal gap was found. The average vertical gap reduction from the baseline until 12 months was 0.92±1.11 mm in platform switching and 0.29±0.85 mm in platform matching (P<0.05. Conclusions. Within the limitations of the present study, platform switching seemed to be more effective for a better peri-implant alveolar bone vertical and horizontal gap reduction at 1 year.

  10. Trochanteric fracture-implant motion during healing - A radiostereometry (RSA) study.

    Science.gov (United States)

    Bojan, Alicja J; Jönsson, Anders; Granhed, Hans; Ekholm, Carl; Kärrholm, Johan

    2018-03-01

    Cut-out complication remains a major unsolved problem in the treatment of trochanteric hip fractures. A better understanding of the three-dimensional fracture-implant motions is needed to enable further development of clinical strategies and countermeasures. The aim of this clinical study was to characterise and quantify three-dimensional motions between the implant and the bone and between the lag screw and nail of the Gamma nail. Radiostereometry Analysis (RSA) analysis was applied in 20 patients with trochanteric hip fractures treated with an intramedullary nail. The following three-dimensional motions were measured postoperatively, at 1 week, 3, 6 and 12 months: translations of the tip of the lag screw in the femoral head, motions of the lag screw in the nail, femoral head motions relative to the nail and nail movements in the femoral shaft. Cranial migration of the tip of the lag screw dominated over the other two translation components in the femoral head. In all fractures the lag screw slid laterally in the nail and the femoral head moved both laterally and inferiorly towards the nail. All femoral heads translated posteriorly relative to the nail, and rotations occurred in both directions with median values close to zero. The nail tended to retrovert in the femoral shaft. Adverse fracture-implant motions were detected in stable trochanteric hip fractures treated with intramedullary nails with high resolution. Therefore, RSA method can be used to evaluate new implant designs and clinical strategies, which aim to reduce cut-out complications. Future RSA studies should aim at more unstable fractures as these are more likely to fail with cut-out. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Confusing the drug facts on one nonprescription drug label with those on another: The Drug Facts Label as a text schema

    Directory of Open Access Journals (Sweden)

    Michael P Ryan

    2016-04-01

    Full Text Available The Drug Facts Label is designed to guide consumers in comparing nonprescription drugs. Undergraduates studied and recalled drug facts for three analgesic or non-analgesic labels using Drug Facts Label headings as retrieval cues. They then studied and recalled drug facts from an aspirin label. Aspirin recall was greater when the prior labels were analgesics, but prior-label intrusion errors were also greater. These two effects were associated with the number of prior drug labels on which facilitating and interfering drug facts appeared. Using the Drug Facts Label schema to read drug labels can both enhance and degrade the recall of nonprescription drug facts.

  12. Influence of Implant Positions and Occlusal Forces on Peri-Implant Bone Stress in Mandibular Two-Implant Overdentures: A 3-Dimensional Finite Element Analysis.

    Science.gov (United States)

    Alvarez-Arenal, Angel; Gonzalez-Gonzalez, Ignacio; deLlanos-Lanchares, Hector; Brizuela-Velasco, Aritza; Dds, Elena Martin-Fernandez; Ellacuria-Echebarria, Joseba

    2017-12-01

    The aim of this study was to evaluate and compare the bone stress around implants in mandibular 2-implant overdentures depending on the implant location and different loading conditions. Four 3-dimensional finite element models simulating a mandibular 2-implant overdenture and a Locator attachment system were designed. The implants were located at the lateral incisor, canine, second premolar, and crossed-implant levels. A 150 N unilateral and bilateral vertical load of different location was applied, as was 40 N when combined with midline load. Data for von Mises stress were produced numerically, color coded, and compared between the models for peri-implant bone and loading conditions. With unilateral loading, in all 4 models much higher peri-implant bone stress values were recorded on the load side compared with the no-load side, while with bilateral occlusal loading, the stress distribution was similar on both sides. In all models, the posterior unilateral load showed the highest stress, which decreased as the load was applied more mesially. In general, the best biomechanical environment in the peri-implant bone was found in the model with implants at premolar level. In the crossed-implant model, the load side greatly altered the biomechanical environment. Overall, the overdenture with implants at second premolar level should be the chosen design, regardless of where the load is applied. The occlusal loading application site influences the bone stress around the implant. Bilateral occlusal loading distributes the peri-implant bone stress symmetrically, while unilateral loading increases it greatly on the load side, no matter where the implants are located.

  13. Survival of Dental Implants Placed in Grafted and Nongrafted Bone: A Retrospective Study in a University Setting.

    Science.gov (United States)

    Tran, Duong T; Gay, Isabel C; Diaz-Rodriguez, Janice; Parthasarathy, Kavitha; Weltman, Robin; Friedman, Lawrence

    2016-01-01

    To compare dental implant survival rates when placed in native bone and grafted sites. Additionally, risk factors associated with dental implant loss were identified. This study was based on the hypothesis that bone grafting has no effect on implant survival rates. A retrospective chart review was conducted for patients receiving dental implants at the University of Texas, School of Dentistry from 1985 to 2012. Exclusion criteria included patients with genetic diseases, radiation and chemotherapy, or an age less than 18 years. To avoid misclassification bias, implants were excluded if bone grafts were only done at the same time of placement. Data on age, sex, tobacco use, diabetes, osteoporosis, anatomical location of the implant, implant length and width, bone graft, and professional maintenance were collected for analysis. A total of 1,222 patients with 2,729 implants were included. The cumulative survival rates at 5 and 10 years were 92% and 87% for implants placed in native bone and 90% and 79% for implants placed in grafted bone, respectively. The results from multivariate analysis (Cox regression) indicated no significant difference in survival between the two groups; having maintenance therapy after implant placement reduced the failure rate by 80% (P dental implant survival rate when implants were placed in native bone or bone-grafted sites. Smoking and lack of professional maintenance were significantly related to increased implant loss.

  14. Alveolar Ridge Reconstruction with Titanium Meshes and Simultaneous Implant Placement: A Retrospective, Multicenter Clinical Study

    Directory of Open Access Journals (Sweden)

    Raquel Zita Gomes

    2016-01-01

    Full Text Available Objective. To evaluate horizontal bone gain and implant survival and complication rates in patients treated with titanium meshes placed simultaneously with dental implants and fixed over them. Methods. Twenty-five patients treated with 40 implants and simultaneous guided bone regeneration with titanium meshes (i–Gen®, MegaGen, Gyeongbuk, Republic of Korea were selected for inclusion in the present retrospective multicenter study. Primary outcomes were horizontal bone gain and implant survival; secondary outcomes were biological and prosthetic complications. Results. After the removal of titanium meshes, the CBCT evaluation revealed a mean horizontal bone gain of 3.67 mm (±0.89. The most frequent complications were mild postoperative edema (12/25 patients: 48% and discomfort after surgery (10/25 patients: 40%; these complications were resolved within one week. Titanium mesh exposure occurred in 6 patients (6/25 : 24%: one of these suffered partial loss of the graft and another experienced complete graft loss and implant failure. An implant survival rate of 97.5% (implant-based and a peri-implant marginal bone loss of 0.43 mm (±0.15 were recorded after 1 year. Conclusions. The horizontal ridge reconstruction with titanium meshes placed simultaneously with dental implants achieved predictable satisfactory results. Prospective randomized controlled trials on a larger sample of patients are required to validate these positive outcomes.

  15. Bone reactions adjacent to titanium implants subjected to static load. A study in the dog (I)

    DEFF Research Database (Denmark)

    Gotfredsen, K; Berglundh, T; Lindhe, J

    2001-01-01

    The aim of the study was to evaluate the effect of lateral static load induced by an expansion force on the bone/implant interface and adjacent peri-implant bone. In 3 beagle dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. Twelve weeks later 8 implants of the ITI Dental...... Implant System were placed in each dog. Crowns connected in pairs were screwed on the implants 12 weeks after implant installation. The connected crowns contained an orthodontic expansion screw yielding 4 loading units in each dog. Clinical registrations, standardized radiographs and fluorochrome labeling...... were carried out during the 24-week loading period. Biopsies were harvested and processed for ground sectioning. The sections were subjected to histological examination. No evident marginal bone loss was observed at either test or control sites. The bone density and the mineralized bone-to-implant...

  16. A Clinical Retrospective Study of Distal Extension Removable Partial Denture with Implant Surveyed Bridge or Stud Type Attachment

    Science.gov (United States)

    Bae, Eun-Bin; Kim, Seong-Jong; Choi, Jae-Won; Jeon, Young-Chan; Jeong, Chang-Mo; Yun, Mi-Jung; Lee, So-Hyoun

    2017-01-01

    This study was performed to make comparative analysis of the clinical findings between the two different types of the implant-assisted removable partial dentures: removable partial dentures using implant surveyed bridge as an abutment (ISBRPD) and overdenture type of removable partial denture using implant attachment (IARPD). Implant cumulative survival rate, marginal bone resorption, probing depth, peri-implant inflammation, bleeding, plaque, calculus, and complications were evaluated on 24 patients who were treated with implants in conjunction with removable partial denture and have used them for at least 1 year (ISCRPD: n = 12; IARPD: n = 12). There was no failed implant and all implants were functioning without clinical mobility. Marginal bone loss of ISCRPD (1.44 ± 0.57 mm) was significantly lower than that of IARPD (p 0.05), while the calculus was significantly more observed in ISCRPD group than in IARPD group (p < 0.05). The retention loss of IARPD was the most common complication. Within the limits of the present study, it was found that well-planned ISBRPD was clinically appropriate. Longitudinal and systematic clinical studies are necessary to confirm these results. PMID:28497062

  17. A Clinical Retrospective Study of Distal Extension Removable Partial Denture with Implant Surveyed Bridge or Stud Type Attachment

    Directory of Open Access Journals (Sweden)

    Eun-Bin Bae

    2017-01-01

    Full Text Available This study was performed to make comparative analysis of the clinical findings between the two different types of the implant-assisted removable partial dentures: removable partial dentures using implant surveyed bridge as an abutment (ISBRPD and overdenture type of removable partial denture using implant attachment (IARPD. Implant cumulative survival rate, marginal bone resorption, probing depth, peri-implant inflammation, bleeding, plaque, calculus, and complications were evaluated on 24 patients who were treated with implants in conjunction with removable partial denture and have used them for at least 1 year (ISCRPD: n=12; IARPD: n=12. There was no failed implant and all implants were functioning without clinical mobility. Marginal bone loss of ISCRPD (1.44 ± 0.57 mm was significantly lower than that of IARPD (p0.05, while the calculus was significantly more observed in ISCRPD group than in IARPD group (p<0.05. The retention loss of IARPD was the most common complication. Within the limits of the present study, it was found that well-planned ISBRPD was clinically appropriate. Longitudinal and systematic clinical studies are necessary to confirm these results.

  18. Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

    Science.gov (United States)

    Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

    2014-10-01

    New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. Drug Facts

    Medline Plus

    Full Text Available ... to main content Easy-to-Read Drug Facts Search form Search Menu Home Drugs That People Abuse Alcohol Facts ... Past Drug Use Prevention Phone Numbers and Websites Search Share Listen English Español Information about this page ...

  20. Treatment by stereotactic radiotherapy of tumoral injuries after implant placement: preliminary study

    International Nuclear Information System (INIS)

    Meingan, P.; Rio, E.; Labbe-Devilliers, C.; Geffroy, D.; Ricaud-Couprie, M.; Doutriaux-Dumoulin, I.

    2009-01-01

    Objective: to evaluate the interest and the place of stereotactic radiotherapy in the treatment of primitive or secondary tumoral injuries of the liver. To describe the technique of implants placement. Conclusion: the liver stereotactic radiotherapy, after implant placement, seems to be an alternative or complementary therapy to the radiofrequency for patients refused for surgery, with moderated side effects and a noticeable survival. Complementary studies, especially associated to radiofrequency must be considered. (N.C.)

  1. Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

    Science.gov (United States)

    Scarano, Antonio; Valbonetti, Luca; Degidi, Marco; Pecci, Raffaella; Piattelli, Adriano; de Oliveira, P S; Perrotti, Vittoria

    2016-10-01

    The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

  2. Immediate Loading of Single Implants in the Anterior Maxilla: A 1-Year Prospective Clinical Study on 34 Patients

    Directory of Open Access Journals (Sweden)

    Miguel Stanley

    2017-01-01

    Full Text Available Purpose. To present the outcomes of immediately loaded single implants placed in the anterior maxilla. Methods. Over a 2-year period, all patients referred to a private clinic were considered for enrolment in this study. Inclusion criteria were single-tooth placement in postextraction sockets or healed sites of the anterior maxilla. All implants were immediately loaded and followed for a period of 1 year after the placement of definitive crowns. The outcome measures were implant stability, survival, and success. Results. 34 patients were selected and 43 tapered implants with a knife-edge thread design and a nanostructured, calcium-incorporated surface (Anyridge®, Megagen, Gyeongsang, Korea were installed. Two implants were not sufficiently stable at placement (ISQ < 60 and were considered failed for immediate loading; 41 implants had an ISQ ≥ 60 at placement and were immediately loaded. One year after the placement of definitive crowns, no implant failures were reported, for a survival rate of 100%. No biological complications were found, but 2 implants had their prosthetic abutments loosened: the implant success rate was 95.2%. Conclusions. In the present study on the immediate loading of single implants in the anterior maxilla, positive outcomes were reported, with high survival (100% and success (95.2% rates (the present study has been registered in the ISRCTN registry, a publicly available trial register recognized by WHO and ICMJE, with number ISRCTN12935478.

  3. The effects of implant surface roughness and surgical technique on implant fixation in an in vitro model.

    NARCIS (Netherlands)

    Shalabi, M.M.; Wolke, J.G.C.; Jansen, J.A.

    2006-01-01

    OBJECTIVES: The aim of the present study was to determine the relationship between implant surface parameters, surgical approach and initial implant fixation. MATERIAL AND METHODS: Sixty tapered, conical, screw-shaped implants with machined or etched surface topography were implanted into the

  4. Uneventful Anterior Migration of Intravitreal Ozurdex Implant in a Patient with Iris-Sutured Intraocular Lens and Descemet Stripping Automated Endothelial Keratoplasty.

    Science.gov (United States)

    Zafar, Andleeb; Aslanides, Ioannis M; Selimis, Vasileios; Tsoulnaras, Konstantinos I; Tabibian, David; Kymionis, George D

    2018-01-01

    We report here the case of a patient with anterior segment migration of intravitreal dexamethasone implant as well as its management and outcome. The patient had the following sequence of events: complicated cataract surgery, iris-sutured intraocular lens implant, followed by cystoid macular edema treated with intravitreal Avastin, retinal vein occlusion treated with intravitreal dexamethasone implant, corneal decompensation treated with Descemet stripping automated endothelial keratoplasty (DSAEK), and finally recurrence of macular edema treated with repeated intravitreal dexamethasone implant. Dexamethasone implant had completely dissolved from the eye 12 weeks after insertion without any complication. A conservative approach with regular monitoring in the situation of a quiet anterior segment without any corneal decompensation can provide enough time for the implant to dissolve without causing any complication to the involved eye, avoiding any additional surgical intervention, as presented in this case report. Despite the fact that the implant was left for natural dissolution, there were no adverse effects related to the graft or the eye.

  5. Dose distribution close to metal implants in Gamma Knife Radiosurgery: A Monte Carlo study

    International Nuclear Information System (INIS)

    Cheung, Joel Y.C.; Yu, K.N.; Chan, Josie F.K.; Ho, Robert T.K.; Yu, C.P.

    2003-01-01

    Materials with high atomic numbers favor the occurrence of the photoelectric effect when they are irradiated with gamma rays. Therefore, the photoelectric effects of metal implants within the target regions in Gamma Knife Radiosurgery are worth studying. In the present work, Monte Carlo simulations using EGS4 were employed to investigate the resulting dose enhancements. A dose enhancement as high as 10% was observed close to a platinum implant along the x and y axes, while no significant dose enhancements were observed for silver, stainless steel 301, and titanium ones. A dose enhancement as high as 20% was observed close to the platinum implant along the z axis at the superior position of the metal-phantom interface and was 10% higher for other metal implants

  6. Joint immobilization inhibits spontaneous hyaline cartilage regeneration induced by a novel double-network gel implantation.

    Science.gov (United States)

    Arakaki, Kazunobu; Kitamura, Nobuto; Kurokawa, Takayuki; Onodera, Shin; Kanaya, Fuminori; Gong, Jian-Ping; Yasuda, Kazunori

    2011-02-01

    We have recently discovered that spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect in the rabbit, when we implant a novel double-network (DN) gel plug at the bottom of the defect. To clarify whether joint immobilization inhibits the spontaneous hyaline cartilage regeneration, we conducted this study with 20 rabbits. At 4 or 12 weeks after surgery, the defect in the mobile knees was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen, while no cartilage tissues were observed in the defect in the immobilized knees. Type-2 collagen, Aggrecan, and SOX9 mRNAs were expressed only in the mobile knees at each period. This study demonstrated that joint immobilization significantly inhibits the spontaneous hyaline cartilage regeneration induced by the DN gel implantation. This fact suggested that the mechanical environment is one of the significant factors to induce this phenomenon.

  7. Intraoperative HDR implant boost for breast cancer (preliminary results)

    International Nuclear Information System (INIS)

    Rodriguez, I.; Torre, M. de la; Gonzalez, E.; Bourel, V.

    1996-01-01

    Introduction: In spite of the fact that it is been discussed whether or not a boost is necessary for all conservative treated breast cancer patients, it is a generalized radiotherapy practice. Since september 1993 we developed a breast conservative protocol for early stage breast cancer (T1-T2) with intraoperative HDR implant boost. Side effects, cosmetic results and recurrence rates are reviewed. Method and Material: From September 1993 we treated 55 patients with intraoperative HDR implant boost to the lumpectomy site for clinical T1 or T2 invasive breast cancer, followed by external megavoltage radiotherapy to the entire breast. We used the Nucletron microselectron HDR remote afterloading system with flexible implant tubes. The geometric distribution of the tubes was performed according to the 'Paris' configuration. Each implant was evaluated by calculating the dose-volume natural histograms. The HDR fractionation schedule consists of three fractions of 4.5Gy each given at least 48 hs apart, and starting between 48-72hs from surgical procedure. The external radiotherapy to the entire breast started one week after the completion of brachytherapy, using conventional fractionation of 5 fractions per week, 1,8Gy per fraction up to 45-50Gy. Results: So far there is not any local recurrence, but medium follow up is only 18 months. We did not observe any acute damage and the cosmetic outcome was 60% excellent, 30% good and 10% acceptable. Two patients developed localized fibrosis, in both the implant involved the submamary fold. Conclusion: The intraoperative implant is the most accurate way to localize the lumpectomy site, to define the target volume, decrease the total treatment time and avoid a second anesthetic procedure without delaying the inpatient time or the initial wound healing process

  8. Nanohydroxyapatite Silicate-Based Cement Improves the Primary Stability of Dental Implants: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Hooman Khorshidi

    2017-01-01

    Full Text Available Objectives. Insufficient cortical bone volume when placing implants can lead to lack of primary stability. The use of cement as a bone fill material in bone defects around dental implant could result in better clinical outcome. HA has shown excellent biological properties in implant dentistry. The purpose of this study was to evaluate the effect of nanohydroxyapatite powder (Nano-HA in combination with accelerated Portland cement (APC on implant primary stability in surgically created circumferential bone defects in a bovine rib in vitro model. Materials and Methods. Sixteen bovine rib bones and thirty-six implants of same type and size (4 mm × 10 mm were used. Implants were divided into six groups: no circumferential bone defect, defect and no grafting, bone chips grafting, Nano-HA grafting, APC grafting, and Nano-HA mixed to APC grafting (Nano-HA-APC. Circumferential defects around the implants were prepared. The implant stability quotient (ISQ values were measured before and after the grafting. Results. APC exhibited the highest ISQ values. A significant increase of ISQ values following the grafting of Nano-HA-APC (18.08±5.82 and APC alone (9.50±4.12 was achieved. Increase of ISQ values after 72 hours was 24.16±5.01 and 17.58±4.89, respectively. Nano-HA grafting alone exhibited the least rise in ISQ values. Conclusions. Nanohydroxyapatite silicate-based cement could improve the primary stability of dental implants in circumferential bone defect around implants.

  9. The perception of stress pattern in young cochlear implanted children: an EEG study

    Directory of Open Access Journals (Sweden)

    Niki Katerina Vavatzanidis

    2016-03-01

    Full Text Available Children with sensorineural hearing loss may (regain hearing with a cochlear implant – a device that transforms sounds into electric pulses and bypasses the dysfunctioning inner ear by stimulating the auditory nerve directly with an electrode array. Many implanted children master the acquisition of spoken language successfully, yet we still have little knowledge of the actual input they receive with the implant and specifically which language sensitive cues they hear. This would be important however, both for understanding the flexibility of the auditory system when presented with stimuli after a (life-long phase of deprivation and for planning therapeutic intervention. In rhythmic languages the general stress pattern conveys important information about word boundaries. Infant language acquisition relies on such cues and can be severely hampered when this information is missing, as seen for dyslexic children and children with specific language impairment. Here we ask whether children with a cochlear implant perceive differences in stress patterns during their language acquisition phase and if they do, whether it is present directly following implant stimulation or if and how much time is needed for the auditory system to adapt to the new sensory modality. We performed a longitudinal ERP study, testing in bimonthly intervals the stress pattern perception of 17 young hearing impaired children (age range: 9-50 months; mean: 22 months during their first 6 months of implant use. An additional session before the implantation served as control baseline. During a session they passively listened to an oddball paradigm featuring the disyllable baba, which was stressed either on the first or second syllable (trochaic vs. iambic stress pattern. A group of age-matched normal hearing children participated as controls.Our results show, that within the first 6 months of implant use the implanted children develop a negative mismatch response for iambic but not

  10. The Perception of Stress Pattern in Young Cochlear Implanted Children: An EEG Study.

    Science.gov (United States)

    Vavatzanidis, Niki K; Mürbe, Dirk; Friederici, Angela D; Hahne, Anja

    2016-01-01

    Children with sensorineural hearing loss may (re)gain hearing with a cochlear implant-a device that transforms sounds into electric pulses and bypasses the dysfunctioning inner ear by stimulating the auditory nerve directly with an electrode array. Many implanted children master the acquisition of spoken language successfully, yet we still have little knowledge of the actual input they receive with the implant and specifically which language sensitive cues they hear. This would be important however, both for understanding the flexibility of the auditory system when presented with stimuli after a (life-) long phase of deprivation and for planning therapeutic intervention. In rhythmic languages the general stress pattern conveys important information about word boundaries. Infant language acquisition relies on such cues and can be severely hampered when this information is missing, as seen for dyslexic children and children with specific language impairment. Here we ask whether children with a cochlear implant perceive differences in stress patterns during their language acquisition phase and if they do, whether it is present directly following implant stimulation or if and how much time is needed for the auditory system to adapt to the new sensory modality. We performed a longitudinal ERP study, testing in bimonthly intervals the stress pattern perception of 17 young hearing impaired children (age range: 9-50 months; mean: 22 months) during their first 6 months of implant use. An additional session before the implantation served as control baseline. During a session they passively listened to an oddball paradigm featuring the disyllable "baba," which was stressed either on the first or second syllable (trochaic vs. iambic stress pattern). A group of age-matched normal hearing children participated as controls. Our results show, that within the first 6 months of implant use the implanted children develop a negative mismatch response for iambic but not for trochaic

  11. Primary prevention of peri-implantitis: managing peri-implant mucositis.

    Science.gov (United States)

    Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; Lambert, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni E; Schwarz, Frank; Serino, Giovanni; Tomasi, Cristiano; Zitzmann, Nicola U

    2015-04-01

    Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considered as a preventive measure for the onset of peri-implantitis. Therefore, the remit of this working group was to assess the prevalence of peri-implant diseases, as well as risks for peri-implant mucositis and to evaluate measures for the management of peri-implant mucositis. Discussions were informed by four systematic reviews on the current epidemiology of peri-implant diseases, on potential risks contributing to the development of peri-implant mucositis, and on the effect of patient and of professionally administered measures to manage peri-implant mucositis. This consensus report is based on the outcomes of these systematic reviews and on the expert opinion of the participants. Key findings included: (i) meta-analysis estimated a weighted mean prevalence for peri-implant mucositis of 43% (CI: 32-54%) and for peri-implantitis of 22% (CI: 14-30%); (ii) bleeding on probing is considered as key clinical measure to distinguish between peri-implant health and disease; (iii) lack of regular supportive therapy in patients with peri-implant mucositis was associated with increased risk for onset of peri-implantitis; (iv) whereas plaque accumulation has been established as aetiological factor, smoking was identified as modifiable patient-related and excess cement as local risk indicator for the development of peri-implant mucositis; (v) patient-administered mechanical plaque control (with manual or powered toothbrushes) has been shown to be an effective preventive measure; (vi) professional intervention

  12. Structural-chemical characteristics of implanted metals

    International Nuclear Information System (INIS)

    Kozejkin, B.V.; Pavlov, P.V.; Pitirimova, E.A.; Frolov, A.I.

    1988-01-01

    Corrosion and structural characteristics of metallic layers implanted by ions of chemically active impurities and noble gases are studied. Dependence of experimental results on parameters of initial materials and technological conditions of implantation is established. In studying corrosion characteristics of implanted metals a strong dependence of chemical passivation effect on technological conditions of ion-implantation and structure of initial material is stated. On the basis of developed mathematical model of chemical passivation effect it is shown that increase of corrosion characteristics of implanted metals is defined by superposition of surface and volumetric mechanisms

  13. Mandibular Overdentures Supported by 6-mm Dental Implants : A 1-Year Prospective Cohort Study

    NARCIS (Netherlands)

    Gulje, Felix; Raghoebar, Gerry M.; Ter Meulen, Jan-Willem P.; Vissink, Arjan; Meijer, Henny J. A.; Guljé, Felix

    Background: The extremely resorbed edentulous mandible, with a bone height of 8 mm or less, is still a challenge in implant dentistry. Recently, dental implants of 6 mm in length have been developed. Purpose: The purpose of this 1-year prospective cohort study was to evaluate treatment outcome of

  14. Inflatable penile prosthesis implant length with baseline characteristic correlations: preliminary analysis of the PROPPER study.

    Science.gov (United States)

    Bennett, Nelson; Henry, Gerard; Karpman, Edward; Brant, William; Jones, LeRoy; Khera, Mohit; Kohler, Tobias; Christine, Brian; Rhee, Eugene; Kansas, Bryan; Bella, Anthony J

    2017-12-01

    "Prospective Registry of Outcomes with Penile Prosthesis for Erectile Restoration" (PROPPER) is a large, multi-institutional, prospective clinical study to collect, analyze, and report real-world outcomes for men implanted with penile prosthetic devices. We prospectively correlated co-morbid conditions and demographic data with implanted penile prosthesis size to enable clinicians to better predict implanted penis size following penile implantation. We present many new data points for the first time in the literature and postulate that radical prostatectomy (RP) is negatively correlated with penile corporal length. Patient demographics, medical history, baseline characteristics and surgical details were compiled prospectively. Pearson correlation coefficient was generated for the correlation between demographic, etiology of ED, duration of ED, co-morbid conditions, pre-operative penile length (flaccid and stretched) and length of implanted penile prosthesis. Multivariate analysis was performed to define predictors of implanted prosthesis length. From June 2011 to June 2017, 1,135 men underwent primary implantation of penile prosthesis at a total of 11 study sites. Malleable (Spectra), 2-piece Ambicor, and 3-piece AMS 700 CX/LGX were included in the analysis. The most common patient comorbidities were CV disease (26.1%), DM (11.1%), and PD (12.4%). Primary etiology of ED: RP (27.4%), DM (20.3%), CVD (18.0%), PD (10.3%), and Priapism (1.4%), others (22.6%). Mean duration of ED is 6.2¡À4.1 years. Implant length was weakly negatively correlated with White/Caucasian (r=-0.18; Pprosthesis length is negatively correlated with some ethnic groups, prostatectomy, and incontinence. Positive correlates include CV disease, preoperative stretched penile length, and flaccid penile length.

  15. A pilot study of implantable cardiac device interrogation by emergency department personnel.

    Science.gov (United States)

    Neuenschwander, James F; Hiestand, Brian C; Peacock, W Frank; Billings, John M; Sondrup, Cole; Hummel, John D; Abraham, William T

    2014-03-01

    Implanted devices (eg, pacemakers and defibrillators) provide valuable information and may be interrogated to obtain diagnostic information and to direct management. During admission to an emergency department (ED), significant time and cost are spent waiting for device manufacturer representatives or cardiologists to access the data. If ED personnel could safely interrogate implanted devices, more rapid disposition could occur, thus leading to potentially better outcomes at a reduced cost. This was a pilot study examining the feasibility of ED device interrogation. This was a prospective convenience sample study of patients presenting to the ED with any chief complaint and who had an implantable device capable of being interrogated by a Medtronic reader. After obtaining informed consent, study patients underwent device interrogation by ED research personnel. After reviewing the device data, the physician documented their opinions of the value of data in aiding care. Patients were followed up at intervals ranging from 30 days out to 1 year to determine adverse events relating to interrogation. Forty-four patients underwent device interrogation. Their mean age was 56 ± 14.7 years (range, 28-83), 75% (33/44) were male and 75% (33/44) were hospitalized from the ED. The interrogations took less than 10 minutes 89% of the time. In 60% of the cases, ED physicians reported the data-assisted patient care. No adverse events were reported relating to the ED interrogations. In this pilot study, we found that ED personnel can safely and quickly interrogate implantable devices to obtain potentially useful clinical data.

  16. Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length.

    Science.gov (United States)

    Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

    2018-03-18

    To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System ® ). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results.

  17. The clinical implications of poly implant prothèse breast implants: an overview.

    Science.gov (United States)

    Wazir, Umar; Kasem, Abdul; Mokbel, Kefah

    2015-01-01

    Mammary implants marketed by Poly Implant Prothèse (PIP) were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635) for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

  18. The Clinical Implications of Poly Implant Prothèse Breast Implants: An Overview

    Directory of Open Access Journals (Sweden)

    Umar Wazir

    2015-01-01

    Full Text Available Mammary implants marketed by Poly Implant Prothèse (PIP were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635 for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

  19. Survival Rate of Dental Implants in Patients with History of Periodontal Disease: A Retrospective Cohort Study.

    Science.gov (United States)

    Correia, Francisco; Gouveia, Sónia; Felino, António Campos; Costa, Ana Lemos; Almeida, Ricardo Faria

    To evaluate the differences between the survival rates of implants placed in patients with no history of periodontal disease (NP) and in patients with a history of chronic periodontal disease (CP). A retrospective cohort study was conducted in which all consenting patients treated with dental implants in a private clinic in Oporto, Portugal, from November 2, 2002 through February 11, 2011 were included. All patients were treated consecutively by the same experimental operator. This study aimed to analyze how the primary outcomes (presence of disease, time of placement, and time of loading) and the secondary outcomes (severity-generalized periodontitis, brand, implant length, prosthesis type, prosthesis metal-ceramic extension) influence the survival rate of dental implants. The survival analysis was performed through the Kaplan-Meier method, and the equality of survival distributions for all groups was tested with the log-rank test with a significance level of .05 for all comparisons. The sample consisted of 202 patients (47% NP and 53% CP) and 689 implants (31% NP and 69% CP). The survival rate in the NP and CP groups showed no statistically significant differences (95.8% versus 93.1%; P ≥ .05). Implants were lost before loading in 54.9% of the cases. The majority of the implants were lost in the first year and stabilized after the second year. Survival rates in the NP and CP patients showed no statistically significant differences when comparing the following factors: subclassification of the disease, implant brands, implant length (short/standard), type of prosthesis, extension of the prosthesis metal-ceramic, and time of placement and loading (P ≥ .05). This work disclosed no statistically significant differences in terms of survival rates when compared with the control group. Placing implants in patients with a history of periodontal disease appears to be viable and safe.

  20. Incidence of peri-implant mucositis and peri-implantitis in edentulous patients with an implant-retained mandibular overdenture during a 10-year follow-up period

    NARCIS (Netherlands)

    Meijer, Henny J. A.; Raghoebar, Gerry M.; de Waal, Yvonne C. M.; Vissink, Arjan

    2014-01-01

    Objectives: The aim of this sub-analysis of two prospective studies was to assess the incidence of peri-implant mucositis and peri-implantitis in fully edentulous patients with an implant-retained mandibular overdenture during a 10-year follow-up period. Material and Methods: One hundred and fifty

  1. Study of the relationship between the indication rod of stent on implant CT and the real path of implant fixture insertion considering residual ridge

    International Nuclear Information System (INIS)

    Kim, Do Hoon; Heo, Min Suk; Lee, Sam Sun; Oh, Sung Ook; Choi, Soon Chul; Choi, Hang Moon; Jeon, In Seong

    2003-01-01

    To assess the relationship between the direction of the indicating rod of the radiographic stent for ideal prosthetic design and the actual possible path of implant fixture placement when residual ridge resorption is considered. The study materials considered of 326 implant sites (male 214 cases and female 112 cases) from a total of 106 patients (male 65 patients and female 41 patients) who desired implant prostheses. Computed tomography of patients were taken and reformatted using ToothPix software. Bony defects, bony sclerosis, the change of the direction of indicating rod, and root proximity of the adjacent teeth were examined on the CT-derived images. The rate of the irregular crestal cortex was relatively high on premolar and molar area of maxilla. Mandibular molar area showed relatively high rate of focal sclerosis on the area of implant fixture insertion. The position of the including rods were relatively acceptable on the molar areas of both jaws. However, the position of the indicating rods should be shifted to buccal side with lingual rotation of the apical end on maxillary anterior teeth and premolar area. Clinically determined rod direction and position of the indicating rod for implant placement was not always acceptable for insertion according to the reformatted CT images. The pre-operative treatment plan for implant should be determined carefully, considering the state of the alveolar bone using the reformatted CT images.

  2. Biocompatibility and biodegradation studies of subconjunctival implants in rabbit eyes.

    Directory of Open Access Journals (Sweden)

    Yan Peng

    Full Text Available Sustained ocular drug delivery is difficult to achieve. Most drugs have poor penetration due to the multiple physiological barriers of the eye and are rapidly cleared if applied topically. Biodegradable subconjunctival implants with controlled drug release may circumvent these two problems. In our study, two microfilms (poly [d,l-lactide-co-glycolide] PLGA and poly[d,l-lactide-co-caprolactone] PLC were developed and evaluated for their degradation behavior in vitro and in vivo. We also evaluated the biocompatibility of both microfilms. Eighteen eyes (9 rabbits were surgically implanted with one type of microfilm in each eye. Serial anterior-segment optical coherence tomography (AS-OCT scans together with serial slit-lamp microscopy allowed us to measure thickness and cross-sectional area of the microfilms. In vitro studies revealed bulk degradation kinetics for both microfilms, while in vivo studies demonstrated surface erosion kinetics. Serial slit-lamp microscopy revealed no significant inflammation or vascularization in both types of implants (mean increase in vascularity grade PLGA50/50 12±0.5% vs. PLC70/30 15±0.6%; P = 0.91 over a period of 6 months. Histology, immunohistochemistry and immuno-fluorescence also revealed no significant inflammatory reaction from either of the microfilms, which confirmed that both microfilms are biocompatible. The duration of the drug delivery can be tailored by selecting the materials, which have different degradation kinetics, to suit the desired clinical therapeutic application.

  3. [Suicide, a social fact].

    Science.gov (United States)

    Baudelot, Christian

    2017-04-01

    Treating suicide as a social fact means disregarding its individual and dramatic dimensions. Sociologists do not reason on the basis of specific cases but by studying the variations, in space and time, of suicide rates. Their contribution relates essentially to a renewed perspective on society: suicide is in fact a very accurate indicator of the intensity and quality of the bonds which unite or isolate individuals in a society. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Oxidation and corrosion studies of Al-implanted stainless steel AISI 321 using nuclear reaction and electrochemical techniques

    International Nuclear Information System (INIS)

    Noli, F.; Misaelides, P.; Spathis, P.; Pilakouta, M.; Baumann, H.

    1992-01-01

    The oxidation of Al-implanted (implantation energy 40 keV, dose 10 16 -10 17 Al ions/cm 2 ) AISI 321 stainless steel samples in air has been studied at temperatures between 450 and 650degC using the 16 O(d,p) 17 O nuclear reaction. The determination of the distribution of the implanted Al atoms has been performed using the resonance at 992 keV of the 27 Al(p,γ) 28 Si nuclear reaction. The determined oxygen profiles indicate that the implantation of 5x10 16 and 10 17 Al ions/cm 2 leads to an improvement of the oxidation resistance of the studied steel samples. The passivation/corrosion behaviour of the Al-implanted steel samples in 0.5M aqueous sulphuric acid solution has also been investigated electrochemically using potentiodynamic and cyclovoltammetric techniques. The passivation potential values and the repassivation moving to more positive values indicate an improvement of the corrosion resistance of the Al-implanted steel samples. (orig.)

  5. 10-year survival rate and the incidence of peri-implant disease of 374 titanium dental implants with a SLA surface: a prospective cohort study in 177 fully and partially edentulous patients

    NARCIS (Netherlands)

    van Velzen, F.J.J.; Ofec, R.; Schulten, E.A.J.M.; ten Bruggenkate, C.M.

    2015-01-01

    Purpose This prospective cohort study evaluates the 10-year survival and incidence of peri-implant disease at implant and patient level of sandblasted, large grid, and acid-etched titanium dental implants (Straumann, soft tissue level, SLA surface) in fully and partially edentulous patients.

  6. The efficacy of maxillary protraction protocols with the micro-implant-assisted rapid palatal expander (MARPE) and the novel N2 mini-implant-a finite element study.

    Science.gov (United States)

    Moon, Won; Wu, Kimberley W; MacGinnis, Matthew; Sung, Jay; Chu, Howard; Youssef, George; Machado, Andre

    2015-01-01

    Maxillary protraction with the novel N2 mini-implant- and micro-implant-assisted rapid palatal expander (MARPE) can potentially provide significant skeletal effects without surgery, even in older patients where conventional facemask therapy has limited skeletal effects. However, the skeletal effects of altering the location and direction of force from mini-implant-assisted maxillary protraction have not been extensively analyzed. In this study, the application of the novel N2 mini-implant as an orthopedic anchorage device is explored in its ability to treat patients with class III malocclusions. A 3D cranial mesh model with associated sutures was developed from CT images and Mimics modeling software. Utilizing ANSYS simulation software, protraction forces were applied at different locations and directions to simulate conventional facemask therapy and seven maxillary protraction protocols utilizing the novel N2 mini-implant. Stress distribution and displacement were analyzed. Video animations and superimpositions were created. By changing the vector of force and location of N2 mini-implant, the maxilla was displaced differentially. Varying degrees of forward, downward, and rotational movements were observed in each case. For brachyfacial patients, anterior micro-implant-supported protraction at -45° or intermaxillary class III elastics at -45° are recommended. For dolicofacial patients, either anterior micro-implants at -15° or an intermaxillary spring at +30° is recommended. For mesofacial patients with favorable vertical maxillary position, palatal micro-implants at -30° are recommended; anterior micro-implants at -30° are preferred for shallow bites. For patients with a severe mid-facial deficiency, intermaxillary class III elastics at -30° are most effective in promoting anterior growth of the maxilla. By varying the location of N2 mini-implants and vector of class III mechanics, clinicians can differentially alter the magnitude of forward, downward, and

  7. Prevalence and risk indicators of peri-implantitis in Korean patients with a history of periodontal disease: a cross-sectional study.

    Science.gov (United States)

    Goh, Mi-Seon; Hong, Eun-Jin; Chang, Moontaek

    2017-08-01

    The aim of this study was to analyze the prevalence and risk indicators of peri-implantitis in Korean patients with history of periodontal disease. A total of 444 patients with 1,485 implants were selected from patients who had been treated at the Department of Periodontology, Chonbuk National University Dental Hospital between July 2014 and June 2015. A group with a history of peri-implantitis (HP) (370 patients with 1,189 implants) and a group with a current peri-implantitis (CP) (318 patients with 1,004 implants) were created based on the radiographic and clinical assessments of implants. The prevalence of peri-implantitis was calculated at both the patient and implant levels. The influence of risk variables on the occurrence of peri-implantitis was analyzed using generalized estimating equations analysis. The prevalence of peri-implantitis in the HP and CP groups ranged from 6.7% to 19.7%. The cumulative peri-implantitis rate in the HP group estimated with the Kaplan-Meier method was higher than that in the CP group over the follow-up period. Among the patient-related risk variables, supportive periodontal therapy (SPT) was the only significant risk indicator for the occurrence of peri-implantitis in both groups. In the analysis of implant-related variables, implants supporting fixed dental prosthesis (FDP) and implants with subjective discomfort were associated with a higher prevalence of peri-implantitis than single implants and implants without subjective discomfort in the HP group. The presence of subjective discomfort was the only significant implant-related variable predictive of peri-implantitis in the CP group. Within the limitations of this study, the prevalence of peri-implantitis in Korean patients with a history of periodontal disease was similar to that reported in other population samples. Regular SPT was important for preventing peri-implantitis. Single implants were found to be less susceptible to peri-implantitis than those supporting FDP

  8. Implant rehabilitation in fibula-free flap reconstruction: A retrospective study of cases at 1-18 years following surgery.

    Science.gov (United States)

    Sozzi, Davide; Novelli, Giorgio; Silva, Rebeka; Connelly, Stephen T; Tartaglia, Gianluca M

    2017-10-01

    To determine the dental implant and prostheses success rate in a cohort of patients who underwent a vascularized fibula-free flap (FFF) for maxillary or mandibular reconstruction. The investigators implemented a retrospective cohort study composed of patients who had undergone primary or secondary FFF reconstruction jaw surgery plus placement of 2-6 implants in the reconstructed arch, which were restored with an implant-supported prosthesis. The sample was composed of all patients who underwent FFF surgery between 1998 and 2012 and had either simultaneous or secondary dental implant placement. A total of 28 patients met inclusion criteria. Of these, 22 patients participated in the retrospective review. Patients were examined by an independent observer between January-December 2015. In addition, all patients completed a questionnaire to access satisfaction with the implant-supported prosthesis. The patient cohort consisted of 12 males and 10 females, age 12-70 years. A total of 100 implants were placed, 92 implants in fibular bone and 8 implants in native bone. In the maxilla, 35 implants were placed into fibular bone and 4 into native bone (11 in irradiated patients and 28 in non-irradiated patients). In the mandible, 57 implants were placed into fibular bone and 4 into native bone (15 in irradiated patients and 46 in non-irradiated patients). The mean follow-up after implant loading was 7.8 years (range 1.3-17.5 years). The implant survival rate was 98% (95% CI: 92.2%-99.5%). No statistically significant difference was found in implant success between maxillary and mandibular implants, or between radiated and non-radiated bone. The prostheses success rate, determined by clinical exam and patient satisfaction, was 100%. The results of this study suggest that implant survival is high and implant-supported prostheses are a reliable rehabilitation option in patients whose jaws have been reconstruction with a FFF. Copyright © 2017. Published by Elsevier Ltd.

  9. Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies

    Directory of Open Access Journals (Sweden)

    Michiel W. Pot

    2017-10-01

    Full Text Available Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies. Cartilage regeneration was expressed on an absolute 0–100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

  10. Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

    Science.gov (United States)

    Pot, Michiel W; van Kuppevelt, Toin H; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; de Vries, Rob B M; Daamen, Willeke F

    2017-01-01

    Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP) were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies). Cartilage regeneration was expressed on an absolute 0-100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

  11. Implant Supported Fixed Restorations versus Implant Supported Removable Overdentures: A Systematic Review

    Science.gov (United States)

    Selim, Khaled; Ali, Sherif; Reda, Ahmed

    2016-01-01

    AIM: The aim of this study is to systematically evaluate and compare implant retained fixed restoration versus implant retained over denture. MATERIAL AND METHODS: Search was made in 2 databases including PubMed and PubMed Central. Title and abstract were screened to select studies comparing implant retained fixed restorations versus implant retained removable overdentures. Articles which did not follow the inclusion criteria were excluded. Included papers were then read carefully for a second stage filter, this was followed by manual searching of bibliography of selected articles. RESULTS: The search resulted in 5 included papers. One study evaluated the masticatory function, while the other 4 evaluated the patient satisfaction. Two of them used Visual Analogue Scale (VAS) as a measurement tool, while the other two used VAS and Categorical Scales (CAT). Stability, ability to chew, ability to clean, ability to speak and esthetics were the main outcomes of the 4 included papers. CONCLUSION: Conflicting results was observed between the fixed and removable restorations. PMID:28028423

  12. A comparative study of zinc, magnesium, strontium-incorporated hydroxyapatite-coated titanium implants for osseointegration of osteopenic rats

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Zhou-Shan [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China); Zhou, Wan-Shu [Endocrine & Metabolic Diseases Unit, Affiliated Hospital of Guizhou Medical University, Guizhou 550001 (China); He, Xing-Wen [Department of Orthopaedic Surgery, Hangzhou Bay Hospital of Ningbo, 315000 (China); Liu, Wei [Department of Orthopaedic Surgery, Jingmen No. 1 People' s Hospital, Jingmen 44800, Hubei (China); Bai, Bing-Li; Zhou, Qiang; Huang, Zheng-Liang; Tu, Kai-kai; Li, Hang; Sun, Tao [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China); Lv, Yang-Xun [Department of Orthopaedic Surgery, Wenzhou Central Hospital, Wenzhou, Zhejiang 325000 (China); Cui, Wei [Sichuan Provincial Orthopedics Hospital, No. 132 West First Section First Ring Road, Chengdu, Sichuan 610000 (China); Yang, Lei, E-mail: tzs19900327@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China)

    2016-05-01

    Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), magnesium (Mg), and strontium (Sr) present a beneficial effect on bone growth, and positively affect bone regeneration. The aim of this study was to confirm the different effects of the fixation strength of Zn, Mg, Sr-substituted hydroxyapatite-coated (Zn-HA-coated, Mg-HA-coated, Sr-HA-coated) titanium implants via electrochemical deposition in the osteoporotic condition. Female Sprague–Dawley rats were used for this study. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group HA; group Zn-HA; group Mg-HA and group Sr-HA. Afterwards, all rats from groups HA, Zn-HA, Mg-HA and Sr-HA received implants with hydroxyapatite containing 0%, 10% Zn ions, 10% Mg ions, and 10% Sr ions. Implants were inserted bilaterally in all animals until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. All treatment groups increased new bone formation around the surface of titanium rods and push-out force; group Sr-HA showed the strongest effects on new bone formation and biomechanical strength. Additionally, there are significant differences in bone formation and push-out force was observed between groups Zn-HA and Mg-HA. This finding suggests that Zn, Mg, Sr-substituted hydroxyapatite coatings can improve implant osseointegration, and the 10% Sr coating exhibited the best properties for implant osseointegration among the tested coatings in osteoporosis rats. - Highlights: • Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. • However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), Magnesium(Mg), Strontium (Sr) present a benificial effect on bone

  13. Biofilm Analysis of Retrieved Dental Implants after Different Peri-Implantitis Treatments

    Directory of Open Access Journals (Sweden)

    Thaise C. Geremias

    2017-01-01

    Full Text Available The aim of the current study was to analyse the planktonic growth of Streptococcus mutans on the surfaces of three implants retrieved after three different peri-implantitis treatments. Three implants from a male patient with high levels of bone loss were treated by mechanical debridement, chemical decontamination, and implantoplasty. After 4 months of follow-up, the implants were removed. The growth and biofilm formation were measured by spectrophotometry (OD630 nm and scanning electron microscopy (SEM, after 48 hours of incubation. Results showed an average of Streptococcus mutans planktonic growth over the implants of 0.21 nm (mechanical debridement, 0.16 nm (chemical decontamination, and 0.15 nm (implantoplasty. Data were analysed by ANOVA and Tukey’s test (p<0.05 for chemical decontamination and implantoplasty. Implantoplasty and chemical decontamination showed the lowest levels of planktonic growth, indicating a possible influence of the modification procedures on the titanium surface on the initial biofilm attachment.

  14. Clinical and Radiologic Outcomes of Submerged and Nonsubmerged Bone-Level Implants with Internal Hexagonal Connections in Immediate Implantation: A 5-Year Retrospective Study.

    Science.gov (United States)

    Wu, Shiyu; Wu, Xiayi; Shrestha, Rachana; Lin, Jinying; Feng, Zhicai; Liu, Yudong; Shi, Yunlin; Huang, Baoxin; Li, Zhipeng; Liu, Quan; Zhang, Xiaocong; Hu, Mingxuan; Chen, Zhuofan

    2018-02-01

    To evaluate the 5-year clinical and radiologic outcome of immediate implantation using submerged and nonsubmerged techniques with bone-level implants and internal hexagonal connections and the effects of potential influencing factors. A total of 114 bone-level implants (XiVE S plus) with internal hexagonal connections inserted into 72 patients were included. Patients were followed up for 5 years. A t-test was used to statistically evaluate the marginal bone loss between the submerged and nonsubmerged groups. The cumulative survival rate (CSR) was calculated according to the life table method and illustrated with Kaplan-Meier survival curves. Comparisons of the CSR between healing protocols, guided bone regeneration, implants with different sites, lengths, and diameters were performed using log-rank tests. The 5-year cumulative implant survival rates with submerged and nonsubmerged healing were 94% and 96%, respectively. No statistically significant differences in terms of marginal bone loss, healing protocol, application of guided bone regeneration, implant site, or length were observed. High CSRs and good marginal bone levels were achieved 5 years after immediate implantation of bone-level implants with internal hexagonal connections using both the submerged and nonsubmerged techniques. Factors such as implant length, site, and application of guided bone regeneration did not have an impact on the long-term success of the implants. © 2017 by the American College of Prosthodontists.

  15. A study on mutagenic effects of antibiotic-producers by ion implantation

    International Nuclear Information System (INIS)

    Xie Liqing; Zhang Yinfen; Chen Ruyi; Zhou Ruiying; Zhang Peiling; Ying Hengfeng; Yang Guorong; Yang Guifang

    1995-01-01

    Mutagenic effects of Streptomyces ribosidificus, Streptomyces kanamyceticus and the phage-resistant culture of Streptomyces kanamyceticus induced by N + and C + ion implantation with different doses have been investigated. The experimental results show that the death rates of antibiotic-producers increase with the increase of ion implantation dose, and the form mutation of the antibiotic-producers is rather obvious. After N + ion implantation, the titer units increase by 10%-25%, 5.2%-12.1% and 2.1%-12.75% for the above three strains respectively; while after C + ion implantation the titer units increase by 10%-16.9%, 1.05%-3.08% and 5%-20% respectively. The selected strains of Micromonospora echimospoora and Streptomyces kanamyceticus after N + ion implantation have been used in the factory. The increase of production is 20% and 12.5% respectively and marked economic benefits are obtained

  16. Bone Loss at Implant with Titanium Abutments Coated by Soda Lime Glass Containing Silver Nanoparticles: A Histological Study in the Dog

    Science.gov (United States)

    Martinez, Arturo; Guitián, Francisco; López-Píriz, Roberto; Bartolomé, José F.; Cabal, Belén; Esteban-Tejeda, Leticia; Torrecillas, Ramón; Moya, José S.

    2014-01-01

    The aim of the present study was to evaluate bone loss at implants connected to abutments coated with a soda-lime glass containing silver nanoparticles, subjected to experimental peri-implantitis. Also the aging and erosion of the coating in mouth was studied. Five beagle dogs were used in the experiments. Three implants were placed in each mandible quadrant: in 2 of them, Glass/n-Ag coated abutments were connected to implant platform, 1 was covered with a Ti-mechanized abutment. Experimental peri-implantitis was induced in all implants after the submarginal placement of cotton ligatures, and three months after animals were euthanatized. Thickness and morphology of coating was studied in abutment cross-sections by SEM. Histology and histo-morphometric studies were carried on in undecalfied ground slides. After the induced peri-implantitis: 1.The abutment coating shown losing of thickness and cracking. 2. The histometry showed a significant less bone loss in the implants with glass/n-Ag coated abutments. A more symmetric cone of bone resorption was observed in the coated group. There were no significant differences in the peri-implantitis histological characteristics between both groups of implants. Within the limits of this in-vivo study, it could be affirmed that abutments coated with biocide soda-lime-glass-silver nanoparticles can reduce bone loss in experimental peri-implantitis. This achievement makes this coating a suggestive material to control peri-implantitis development and progression. PMID:24466292

  17. Bone loss at implant with titanium abutments coated by soda lime glass containing silver nanoparticles: a histological study in the dog.

    Directory of Open Access Journals (Sweden)

    Arturo Martinez

    Full Text Available The aim of the present study was to evaluate bone loss at implants connected to abutments coated with a soda-lime glass containing silver nanoparticles, subjected to experimental peri-implantitis. Also the aging and erosion of the coating in mouth was studied. Five beagle dogs were used in the experiments. Three implants were placed in each mandible quadrant: in 2 of them, Glass/n-Ag coated abutments were connected to implant platform, 1 was covered with a Ti-mechanized abutment. Experimental peri-implantitis was induced in all implants after the submarginal placement of cotton ligatures, and three months after animals were euthanatized. Thickness and morphology of coating was studied in abutment cross-sections by SEM. Histology and histo-morphometric studies were carried on in undecalfied ground slides. After the induced peri-implantitis: 1.The abutment coating shown losing of thickness and cracking. 2. The histometry showed a significant less bone loss in the implants with glass/n-Ag coated abutments. A more symmetric cone of bone resorption was observed in the coated group. There were no significant differences in the peri-implantitis histological characteristics between both groups of implants. Within the limits of this in-vivo study, it could be affirmed that abutments coated with biocide soda-lime-glass-silver nanoparticles can reduce bone loss in experimental peri-implantitis. This achievement makes this coating a suggestive material to control peri-implantitis development and progression.

  18. Five-Year Safety Data for More than 55,000 Subjects following Breast Implantation: Comparison of Rare Adverse Event Rates with Silicone Implants versus National Norms and Saline Implants.

    Science.gov (United States)

    Singh, Navin; Picha, George J; Hardas, Bhushan; Schumacher, Andrew; Murphy, Diane K

    2017-10-01

    The U.S. Food and Drug Administration has required postapproval studies of silicone breast implants to evaluate the incidence of rare adverse events over 10 years after implantation. The Breast Implant Follow-Up Study is a large 10-year study (>1000 U.S. sites) evaluating long-term safety following primary augmentation, revision-augmentation, primary reconstruction, or revision-reconstruction with Natrelle round silicone breast implants compared with national norms and outcomes with saline implants. Targeted adverse events in subjects followed for 5 to 8 years included connective tissue diseases, neurologic diseases, cancer, and suicide. The safety population comprised 55,279 women (primary augmentation, n = 42,873; revision-augmentation, n = 6837; primary reconstruction, n = 4828; and revision-reconstruction, n = 741). No targeted adverse events occurred at significantly greater rates in silicone implant groups versus national norms across all indications. The standardized incidence rate (observed/national norm) for all indications combined was 1.4 for cervical/vulvar cancer, 0.8 for brain cancer, 0.3 for multiple sclerosis, and 0.1 for lupus/lupus-like syndrome. Silicone implants did not significantly increase the risk for any targeted adverse events compared with saline implants. The risk of death was similar with silicone versus saline implants across all indications. The suicide rate (10.6 events per 100,000 person-years) was not significantly higher than the national norm. No implant-related deaths occurred. Results from 5 to 8 years of follow-up for a large number of subjects confirmed the safety of Natrelle round silicone implants, with no increased risk of systemic disease or suicide versus national norms or saline implants. Therapeutic, II.

  19. Contribution to 57Fe ion implanted garnet study by Moessbauer effect

    International Nuclear Information System (INIS)

    Kornilios, N.

    1986-11-01

    Due to because of their numerous physical properties, garnets are often used in new technologies. In order to improve their properties, ion implantation of inert gases has been proved to be a powerful technique to elaborate bubble memories. Recently it has been shown that high doses implanted ions, chemically reacting with the matrix could give interesting results. If the bulk is completely amorphized after implantation, further annealings can recrystallize it. In this study Y 3 F 5 O 12 , Y 3 Al 5 O 12 and Gd 3 Ga 5 O 12 single crystals were 100 keV implanted with 57 Fe ions at doses ranging between 10 16 and 10 17 ions cm -2 . The iron chemical states were determined thanks to Conversion Electron Moessbauer Spectroscopy (CEMS) and it was shown that the alloying elements of the matrix could influence the nature of the created phases. After thermal treatments the sample superficial layers were characterized using CEMS, grazing angle X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Rutherford Backscattering Spectroscopy (RBS). Different annealing stages were put forward: the oxidation of the implanted iron below 650 0 C and the garnet recrystallization around 850 0 C with some iron substitution in the garnet octahedral and tetraedral sites. The overstoechiometric iron forms particles of mixed oxides (FeAl) 2 O 3 , (FeGa) 2 O 3 or particles of pure Fe 2 O 3 oxide depending on the garnet. For the first time it is proved that after annealing around 1200-1300 0 C a complete rebuilding of the garnet matrix can induce for these oxide particles at room temperature a Morin transition [fr

  20. Variable-energy positron-beam studies of Ni implanted with He

    International Nuclear Information System (INIS)

    Lynn, K.G.; Chen, D.M.; Nielsen, B.; Pareja, R.; Myers, S.

    1986-01-01

    Variable-energy positron-beam studies have been made on well-annealed polycrystalline Ni samples implanted with 30-, 90-, and 180-keV 4 He ions. The positron-annihilation characteristics were measured with a solid-state Ge detector at a number of different incident-positron energies and after isochronal annealing at various temperatures. The Doppler broadening of the annihilation photons was found to be strongly influenced by the 4 He implantations. The data indicate that trapping of the positrons occurred predominantly at small He bubbles. The variation of the broadening with incident-positron energy was sensitive to the depth distribution of the traps. A diffusion model assuming a square concentration-defect profile was developed and analytically fitted to the parametrized momentum data. These fitted results were compared to Monte Carlo range calculations for 4 He in Ni, and fairly good agreement was found. This investigation demonstrates the capabilities of positron annihilation for nondestructive depth profiling in ion-implanted systems. In addition, it establishes parallels between the trapping behavior of positrons and that reported elsewhere for hydrogen, thereby augmenting the present level of understanding of the technologically important trapping of hydrogen by the bubbles

  1. Microstructures of group III-nitrides after implantation with gallium

    International Nuclear Information System (INIS)

    Kench, P.J.

    2001-05-01

    bubbles. A capping layer was used in an attempt to control the degradation of the implanted layer mechanically, but this was unsuccessful. The evidence from XPS and electron diffraction complemented one another and suggested that Ga-N bonds were in fact present. Thermal and laser anneals were performed in an attempt to lessen the bubble and precipitate damage caused by the implantation of Ga into InN, however no improvement in microstructure uniformity was observed. Gallium implantations into silicon nitride performed by S. A. Almieda (1998) were also studied using various microstructural characterisation techniques. It was found that the implanted Ga existed in a dispersion of colloids (5 nm in diameter). These colloids were found to be void of N, which is surprising since Ga-N bonds were detected by XPS in these specimens. It is proposed that either a low percentage of N remained undetected in the colloids allowing Ga-N bonds to form, or more likely that Ga-N bonds were present at the boundary formed between the Ga colloid and the a-SiN x layer. The microstructure of the layer appeared to be unaffected by the nitrogen concentration in the original a-SiN x layer. Annealing caused a broadening of the Ga colloid depth range and a reduction in the diameter of the colloids. Using CALPHAD, phase diagrams for the Ga-ln-N and Ga-AI-N alloy systems have been proposed. It has been shown that thermodynamic arguments can explain the observations of Al and In precipitation following Ga implantation into AIN and InN, respectively. The coalescence of Ga to form Ga clusters after implantation into a-SiN x is also explained using thermodynamic arguments. (author)

  2. Why are mini-implants lost: the value of the implantation technique!

    Science.gov (United States)

    Romano, Fabio Lourenço; Consolaro, Alberto

    2015-01-01

    The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1) Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2) Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3) Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4) The more precise the lancing procedures, the better the implant placement technique; 5) Self-drilling does not mean higher pressures; 6) Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

  3. Why are mini-implants lost: The value of the implantation technique!

    Directory of Open Access Journals (Sweden)

    Fabio Lourenço Romano

    2015-02-01

    Full Text Available The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1 Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2 Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3 Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4 The more precise the lancing procedures, the better the implant placement technique; 5 Self-drilling does not mean higher pressures; 6 Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

  4. Preoperative Biometric Parameters Predict the Vault after ICL Implantation: A Retrospective Clinical Study.

    Science.gov (United States)

    Zheng, Qian-Yin; Xu, Wen; Liang, Guan-Lu; Wu, Jing; Shi, Jun-Ting

    2016-01-01

    To investigate the correlation between the preoperative biometric parameters of the anterior segment and the vault after implantable Collamer lens (ICL) implantation via this retrospective study. Retrospective clinical study. A total of 78 eyes from 41 patients who underwent ICL implantation surgery were included in this study. Preoperative biometric parameters, including white-to-white (WTW) diameter, central corneal thickness, keratometer, pupil diameter, anterior chamber depth, sulcus-to-sulcus diameter, anterior chamber area (ACA) and central curvature radius of the anterior surface of the lens (Lenscur), were measured. Lenscur and ACA were measured with Rhinoceros 5.0 software on the image scanned with ultrasound biomicroscopy (UBM). The vault was assessed by UBM 3 months after surgery. Multiple stepwise regression analysis was employed to identify the variables that were correlated with the vault. The results showed that the vault was correlated with 3 variables: ACA (22.4 ± 4.25 mm2), WTW (11.36 ± 0.29 mm) and Lenscur (9.15 ± 1.21 mm). The regressive equation was: vault (mm) = 1.785 + 0.017 × ACA + 0.051 × Lenscur - 0.203 × WTW. Biometric parameters of the anterior segment (ACA, WTW and Lenscur) can predict the vault after ICL implantation using a new regression equation. © 2016 The Author(s) Published by S. Karger AG, Basel.

  5. Patient satisfaction relating to implant treatment by undergraduate and postgraduate dental students--a pilot study.

    LENUS (Irish Health Repository)

    Harrison, P

    2009-08-01

    Recordings of patient satisfaction with provision of dental implant treatment are scarce. This study aimed to evaluate satisfaction amongst patients attending for provision of implant treatment by training undergraduate and postgraduate students at Dublin Dental School and Hospital (DDSH). A questionnaire was formulated and distributed to 100 individuals randomly selected from records of patients who had received implant treatment via student clinics in the previous 5 years. The response rate was 68%. Results showed a high overall level of satisfaction with treatment received.

  6. Peri-implant evaluation of osseointegrated implants subjected to orthodontic forces: results after three years of functional loading

    Directory of Open Access Journals (Sweden)

    Bruna de Rezende Marins

    2016-04-01

    Full Text Available ABSTRACT Objective: The objective of this study was to clinically and radiographically assess the peri-implant conditions of implants used as orthodontic anchorage. Methods: Two groups were studied: 1 a test group in which osseointegrated implants were used as orthodontic anchorage, with the application of 200-cN force; and 2 a control group in which implants were not subjected to orthodontic force, but supported a screw-retained prosthesis. Clinical evaluations were performed three, six and nine months after prosthesis installation and 1- and 3-year follow-up examinations. Intraoral periapical radiographs were obtained 30 days after surgical implant placement, at the time of prosthesis installation, and one, two and three years thereafter. The results were compared by Kruskal-Wallis test. Results: There was no statistically significant difference in clinical probing depth (p = 0.1078 or mesial and distal crestal bone resorption (p = 0.1832 during the study period. After three years of follow-up, the mean probing depth was 2.21 mm for the control group and 2.39 mm for the test group. The implants of the control group showed a mean distance between the bone crest and implant shoulder of 2.39 mm, whereas the implants used as orthodontic anchorage showed a mean distance of 2.58 mm at the distal site. Conclusion: Results suggest that the use of stable intraoral orthodontic anchorage did not compromise the health of peri-implant tissues or the longevity of the implant.

  7. Presbycusis occurs after cochlear implantation also: a retrospective study of pure tone thresholds over time.

    Science.gov (United States)

    Trosman, Samuel; Matusik, Deanna Kattah; Ferro, Lia; Gao, Weihua; Saadia-Redleaf, Miriam

    2012-12-01

    To assess aided soundfield pure tone thresholds after cochlear implantation in adults over time. Retrospective case review. Academic tertiary care center. Seventy-seven severe-to-profoundly deafened adults implanted with one of 5 different internal devices. Cochlear implantation. Outcome measures were cochlear implant aided soundfield pure tone thresholds at 250, 500, 1,000, 2,000, 4,000, and 6,000 Hz. For the 77 adult patients in the study, pure tone aided thresholds deteriorated over time at 500, 1,000, 2,000, 4,000, and 6,000 Hz at rates ranging from 0.54 to 0.86 dB per year with the implant (p presbycusis, this deterioration is most prominent at the highest frequencies; however, the incidence and rate of deterioration is higher than that seen in presbycusis. These physiologic changes are not indicative of device failure and do not mean that performance measures will necessarily deteriorate.

  8. Healing at implants placed in an alveolar ridge with a sloped configuration: an experimental study in dogs.

    Science.gov (United States)

    Abrahamsson, Ingemar; Welander, Maria; Linder, Elena; Berglundh, Tord

    2014-02-01

    To study healing around implants placed in an alveolar ridge with a sloped lingual-buccal configuration. Six Labrador dogs were used. Buccal bone defects were prepared in the mandible after extraction of premolars. Three months later, two test implants with a sloped marginal design and two control implants were placed in the chronic defect area with a sloped lingual-buccal configuration of each premolar region. The test implants were placed in such a way that the buccal margin of the implant coincided with the buccal bone crest. The lingual margin of the control implants was placed to a similar depth as the lingual margin of the test implants. Abutments were connected to the implants in the right mandibular premolar region and flaps were sutured around the neck of the abutments. In the left side of the mandible, cover screws were placed and the flaps were sutured to cover the implants. Biopsies were obtained 4 months later and prepared for histological examination. It was demonstrated that healing around implants placed in an alveolar ridge with a sloped lingual-buccal configuration resulted in the preservation of a vertical discrepancy between the lingual and buccal marginal bone levels around implants with either a regular cylindrical outline or a modified marginal portion that matched the slope of the alveolar ridge. As the marginal buccal portion of the control implants with a regular design had no bone support, it is suggested that implants with a modified marginal portion may be considered in recipient sites with a sloped lingual-buccal configuration. © 2012 Wiley Periodicals, Inc.

  9. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

    Directory of Open Access Journals (Sweden)

    B. Schwab

    2010-01-01

    Full Text Available Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (=50 was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed.

  10. Direction-dependent RBS channelling studies in ion implanted LiNbO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Wendler, E., E-mail: elke.wendler@uni-jena.de; Becker, G.; Rensberg, J.; Schmidt, E.; Wolf, S.; Wesch, W.

    2016-07-15

    Damage formation in ion implanted LiNbO{sub 3} was studied by Rutherford backscattering spectrometry (RBS) along various directions of the LiNbO{sub 3} crystal. From the results obtained it can be unambiguously concluded that Nb atoms being displaced during ion implantation preferably occupy the free octahedron sites of the LiNbO{sub 3} lattice structure and most likely also form Nb{sub Li} antisite defects.

  11. Results of bone regenerate study after osteosynthesis with bioinert and calcium phosphate-coated bioactive implants in experimental femoral neck fractures (experimental study

    Directory of Open Access Journals (Sweden)

    K. S. Kazanin

    2015-01-01

    Full Text Available Objective - to analyze the results of X-ray, cytomorphometric and immunohistochemistry experimental studies of bone regenerates after osteosynthesis with bioinert and calcium phosphate-coated bioactive implants. Material and methods. The study was conducted on experimental femoral neck fractures in rabbit males. Reparative osteogenesis processes were studied in groups of bioinert titanium implant osteosynthesis and calcium phosphate-coated bioactive titanium implant osteosynthesis. The animals were clinically followed-up during the postoperative period. X-ray, cytomorphometric and immunohistochemistry studies of samples extracted from femoral bones were conducted over time on days 1, 7, 14, 30 and 60. The animal experiments were kept and treated according to recommendations of international standards, Helsinki Declaration on animal welfare and approved by the local ethics committee. All surgeries were performed under anesthesia, and all efforts were made to minimize the suffering of the animals. Results. In the animal group without femoral neck fracture osteosynthesis, femoral neck pseudoarthrosis was observed at the end of the experiment. The results of cytomorphometric and immunohistochemistry studies conducted on day 60 of the experiment confirmed that the cellular composition of the bone regenerate in the group of calcium phosphate-coated bioactive titanium implants corresponded to a more mature bone tissue than in the group of bioinert titanium implants. Conclusion. The results of the statistical analysis of cytomorphometric and immunohistochemistry data show that the use of calcium phosphate-coated bioactive titanium implants allows to achieve significantly earlier bone tissue regeneration.

  12. Superfund fact sheet: The remedial program. Fact sheet

    International Nuclear Information System (INIS)

    1992-09-01

    The fact sheet describes what various actions the EPA can take to clean up hazardous wastes sites. Explanations of how the criteria for environmental and public health risk assessment are determined and the role of state and local governments in site remediation are given. The fact sheet is one in a series providing reference information about Superfund issues and is intended for readers with no formal scientific training

  13. A study of the bone healing kinetics of plateau versus screw root design titanium dental implants.

    LENUS (Irish Health Repository)

    Leonard, Gary

    2009-03-01

    This study was designed to compare the bone healing process around plateau root from (PRF) and screw root from (SRF) titanium dental implants over the immediate 12 week healing period post implant placement.

  14. Immediate restoration of single tapered implants with nonoccluding provisional crowns: a 5-year clinical prospective study.

    Science.gov (United States)

    Lang, Lisa A; Turkyilmaz, Ilser; Edgin, Wendell A; Verrett, Ronald; Garcia, Lily T

    2014-04-01

    Dental literature has limited number of publications regarding long-term outcome data of immediate restoration of single missing teeth with an implant-supported provisional crown. This 5-year study evaluated hard and soft tissue responses to the immediate placement of single implant-supported provisional crowns. Twenty patients received one dental implant restored immediately with a provisional acrylic resin screw-retained crown. Crestal bone loss was evaluated from standardized periapical radiographs collected at 3-month intervals for the first 21 months followed by a 5-year evaluation. Historical controls acquired from available dental literature were used for comparison. One implant failed within 2 months of surgical placement, presenting with pain and mobility. The remaining implants demonstrated no infection, pain, or radiolucencies. Nineteen implants were clinically immobile, osseointegrated, and asymptomatic at 21 months. At 5 years, one patient died, three patients were noncompliant, and 15 implants were evaluated as functional. Mean bone loss (MBL) at 1 year and 21 months was approximately 0.5 ± 0.5 mm and 0.70 ± 0.26 mm at 5 years. There was no statistically significant difference between MBLs at p provisionalization of single dental implants compares favorably with conventional loading protocols. Long-term data suggest that immediate provisionalization of single dental implants is a viable treatment option. © 2012 Wiley Periodicals, Inc.

  15. Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

    Science.gov (United States)

    Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2015-04-01

    Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

  16. Primary prevention of peri-implantitis: Managing peri-implant mucositis

    OpenAIRE

    Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; LAMBERT, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni; Schwarz, Frank; Serino, Giovanni

    2015-01-01

    Abstract AIMS: Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considere...

  17. Gene expression of inflammation and bone healing in peri-implant crevicular fluid after placement and loading of dental implants. A kinetic clinical pilot study using quantitative real-time PCR.

    Science.gov (United States)

    Slotte, Christer; Lennerås, Maria; Göthberg, Catharina; Suska, Felicia; Zoric, Neven; Thomsen, Peter; Nannmark, Ulf

    2012-10-01

    Early detection of healing complications after placement of dental implants is a pressing but elusive goal. This paper proposes a non-invasive diagnostic tool for monitoring healing- and peri-implant disease specific genes, complementary to clinical evaluations. Eighteen partially edentulous patients were recruited to this pilot study. Three Brånemark TiUnite® implants/patient (Nobel Biocare) were placed in a one-stage procedure. Abutments with smooth or rough (TiUnite®) surface were placed. The test group (n = 9) received fixed bridges (immediate loading), whereas the control group (n = 9) implants were loaded 3 months after surgery. In addition to clinical measurements, crevicular fluid was collected using paper strips at the implant abutments 2, 14, 28, and 90 days postoperative. mRNA was extracted, purified, and converted to cDNA. Quantitative PCR assays for IL-1β, TNF-α, Osteocalcin (OC), Alkaline Phosphatase (ALP), Cathepsin K, Tartrate Resistant Acid Phosphatase, and 18S ribosomal RNA were designed and validated. Relative gene expression levels were calculated. One implant was lost in the control group and three in the test group. In one test patient, one implant showed lowered stability after 2 to 4 weeks and was unloaded. Later implant stability improved which allowed for loading after 3 to 4 months. TNF-α and ALP most commonly showed correlation with clinical parameters followed by IL-1β and OC. The strongest correlation was found for TNF-α with clinical complications at 2 and 14 days (p = .01/r = -048, and p = .0004/r = -0.56, respectively; test and control groups together). In some cases, gene expression predicted clinical complications (TNF-α, ALP, CK). This study is based on samples from few individuals; still, some genes showed correlation with clinical findings. Further studies are needed to refine and optimize the sampling process, to find the appropriate panel, and to validate gene expression for monitoring implant healing. © 2010 Wiley

  18. Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR

    Directory of Open Access Journals (Sweden)

    Duda Georg N

    2011-05-01

    Full Text Available Abstract Background Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions. Methods Wagner SL revision stems with standard (34 mm and increased offset (44 mm were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb. Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses. Results Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses, altering anteversion played a lesser role (5%. Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa. Conclusion Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved.

  19. Main facts 1995

    International Nuclear Information System (INIS)

    1996-01-01

    This report presents the main facts of the studies carried out by the Direction des Etudes et Recherches (DER) of Electricite de France: new applications of electricity, classical and nuclear thermal power plants, electrical equipment, environment protection, monitoring and plants operations

  20. Effect of plasma-rich in platelet-derived growth factors on peri-implant bone healing: An experimental study in canines

    Science.gov (United States)

    Birang, Reza; Torabi, Alireza; Shahabooei, Mohammad; Rismanchian, Mansour

    2012-01-01

    Background: Tissue engineering principles can be exploited to enhance alveolar and peri-implant bone reconstruction by applying such biological factors as platelet-derived growth factors. The objective of the present study is to investigate the effect of autologous plasma-rich in growth factors (on the healing of peri-implant bone in canine mandible). Materials and Methods: In this prospective experimental animal study, two healthy canines of the Iranian mix breed were selected. Three months after removing their premolar teeth on both sides of the mandible, 12 implants of the Osteo Implant Corporationsystem, 5 mm in diameter and 10 mm in length, were selected to be implanted. Plasma rich in growth factors (PRGF) were applied on six implants while the other six were used as plain implants without the plasma. The implants were installed in osteotomy sites on both sides of the mandible to be removed after 4 weeks with the surrounding bones using a trephine bur. Mesio-distal sections and implant blocks, 50 μ in diameter containing the peri-implant bone, were prepared By basic fuchin toluidine-bluefor histological and histomorphometric evaluation by optical microscope. The data were analyzed using Mann-Whitney Test (PPRGF and control groups had no statistically significant differences (P=0.261, P=0.2) although the parameters showed higher measured values in the PRGF group. However, compared to the control, application of PRGF had significantly increased bone-to-implant contact (P=0.028) Conclusion: Based on the results, it may be concluded that application of PRGF on the surface of implant may enhance bone-to-implant contact. PMID:22363370

  1. Estimating the benefit of a second bone anchored hearing implant in unilaterally implanted users with a testband.

    OpenAIRE

    Kompis, Martin; Kurz, Anja; Flynn, Mark; Caversaccio, Marco

    2016-01-01

    Conclusion Using a second bone anchored hearing implant (BAHI) mounted on a testband in unilaterally implanted BAHI users to test its potential advantage pre-operatively under-estimates the advantage of two BAHIs placed on two implants. Objectives To investigate how well speech understanding with a second BAHI mounted on a testband approaches the benefit of bilaterally implanted BAHIs. Method Prospective study with 16 BAHI users. Eight were implanted unilaterally (group A) and eight were impl...

  2. Evaluation of the influence of implant placement timing on the esthetic outcomes of single tooth implant treatment in the anterior maxilla: A retrospective study.

    Science.gov (United States)

    Arora, Himanshu; Ivanovski, Saso

    2018-05-15

    The purpose of this retrospective study was to investigate the influence of implant placement timing on the esthetic outcomes for single implants in the anterior maxilla. One hundred and ten patients (48 males; 62 females) who received a single-tooth implant after extraction either immediately (Type 1); after 4-8 weeks (Type 2); after 8-16 weeks (Type 3); or more than 16 weeks (Type 4) were evaluated in terms of esthetic outcomes after a mean post-placement interval of 26.3 months (range 12-116). Esthetic outcomes were measured using the Pink and White Esthetic Score (PES; WES). Stepwise regression analysis was performed to analyze the effect of timing of placement, as well as patient demographics and other clinical parameters on the esthetic outcomes. No statistically significantly differences in PES were found between the various treatment modalities with Type 1 implants (n = 33) scoring 10.58 ± 1.65 (median: 11), followed by 10.36 ± 2.09 (median: 10.5), 9.68 ± 2.43 (median: 10), and 9.63 ± 2.21 (median: 10) for Type 2 (n = 14), Type 3 (n = 19), and Type 4 (n = 44), respectively. For immediate implants, a trend towards better esthetic outcomes was observed when implant placement was done flaplessly in cases with intact buccal bone (Type 1A, median PES 11) as compared to cases with partial/complete missing buccal plates where a flap was raised (Type 1B, median PES 10). Overall, the only parameter that influenced esthetic outcomes (as measured by PES) was gender, with females having significantly superior results. The median WES was 8 and 96% of the crowns were deemed esthetically acceptable, with crowns placed by specialist prosthodontists yielding higher scores than those placed by general practitioners. Single tooth implants in the anterior maxilla showed satisfactory outcomes when measured with objective esthetic criteria. Timing of implant placement did not significantly influence the esthetic outcomes, although a trend

  3. Influence of Piezosurgery on Bone Healing around Titanium Implants: A Histological Study in Rats.

    Science.gov (United States)

    Sirolli, Marcelo; Mafra, Carlos Eduardo Secco; Santos, Rodrigo Albuquerque Basílio Dos; Saraiva, Luciana; Holzhausen, Marinella; César, João Batista

    2016-01-01

    The aim of this study was to evaluate histomorphometrically the influence of two techniques of dental implant site preparation on bone healing around titanium implants. Fifteen male Wistar rats (±300 g) were used in the study. Each tibia was randomly assigned to receive the implant site preparation either with a conventional drilling technique (control - DRILL group) or with a piezoelectric device (PIEZO group). The animals were sacrificed after 30 days and then the following histomorphometric parameters were evaluated (percentage) separately for cortical and cancellous regions: proportion of mineralized tissue (PMT) adjacent to implant threads (500 μm adjacent); bone area within the threads (BA) and bone-implant contact (BIC). The results demonstrated that there were no statistically significant differences between both groups for cancellous BIC (p>0.05) and cortical PMT (p>0.05). On the other hand, a higher percentage of BA was observed in the PIEZO group in the cortical (71.50±6.91 and 78.28±4.38 for DRILL and PIEZO groups, respectively; ppiezosurgery also showed higher PMT values in the cancellous zone (9.35±5.54 and 18.72±13.21 for DRILL and PIEZO groups, respectively; ppiezosurgery was beneficial to bone healing rates in the cancellous bone region, while the drill technique produced better results in the cortical bone.

  4. Intercavitary implants dosage calculation

    International Nuclear Information System (INIS)

    Rehder, B.P.

    The use of spacial geometry peculiar to each treatment for the attainment of intercavitary and intersticial implants dosage calculation is presented. The study is made in patients with intercavitary implants by applying a modified Manchester technique [pt

  5. Survival of dental implants placed in sites of previously failed implants.

    Science.gov (United States)

    Chrcanovic, Bruno R; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

    2017-11-01

    To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Ion Implantation of Calcium and Zinc in Magnesium for Biodegradable Implant Applications

    Directory of Open Access Journals (Sweden)

    Sahadev Somasundaram

    2018-01-01

    Full Text Available In this study, magnesium was implanted with calcium-ion and zinc-ion at fluences of 1015, 1016, and 1017 ion·cm−2, and its in vitro degradation behaviour was evaluated using electrochemical techniques in simulated body fluid (SBF. Rutherford backscattering spectrometry (RBS revealed that the implanted ions formed layers within the passive magnesium-oxide/hydroxide layers. Electrochemical impedance spectroscopy (EIS results demonstrated that calcium-ion implantation at a fluence of 1015 ions·cm−2 increased the polarisation resistance by 24%, but higher fluences showed no appreciable improvement. In the case of zinc-ion implantation, increase in the fluence decreased the polarisation resistance. A fluence of 1017 ion·cm−2 decreased the polarisation resistance by 65%, and fluences of 1015 and 1016 showed only marginal effect. Similarly, potentiodynamic polarisation results also suggested that low fluence of calcium-ion decreased the degradation rate by 38% and high fluence of zinc-ion increased the degradation rate by 61%. All the post-polarized ion-implanted samples and the bare metal revealed phosphate and carbonate formation. However, the improved degradative behaviour in calcium-ion implanted samples can be due to a relatively better passivation, whereas the reduction in degradation resistance in zinc-ion implanted samples can be attributed to the micro-galvanic effect.

  7. Ultrasonic implant site preparation using piezosurgery: a multicenter case series study analyzing 3,579 implants with a 1- to 3-year follow-up.

    Science.gov (United States)

    Vercellotti, Tomaso; Stacchi, Claudio; Russo, Crescenzo; Rebaudi, Alberto; Vincenzi, Giampaolo; Pratella, Umberto; Baldi, Domenico; Mozzati, Marco; Monagheddu, Chiara; Sentineri, Rosario; Cuneo, Tommaso; Di Alberti, Luca; Carossa, Stefano; Schierano, Gianmario

    2014-01-01

    This multicenter case series introduces an innovative ultrasonic implant site preparation (UISP) technique as an alternative to the use of traditional rotary instruments. A total of 3,579 implants were inserted in 1,885 subjects, and the sites were prepared using a specific ultrasonic device with a 1- to 3-year follow-up. No surgical complications related to the UISP protocol were reported for any of the implant sites. Seventy-eight implants (59 maxillary, 19 mandibular) failed within 5 months of insertion, for an overall osseointegration percentage of 97.82% (97.14% maxilla, 98.75% mandible). Three maxillary implants failed after 3 years of loading, with an overall implant survival rate of 97.74% (96.99% maxilla, 98.75% mandible).

  8. Cochlear implant users' spectral ripple resolution.

    Science.gov (United States)

    Jeon, Eun Kyung; Turner, Christopher W; Karsten, Sue A; Henry, Belinda A; Gantz, Bruce J

    2015-10-01

    This study revisits the issue of the spectral ripple resolution abilities of cochlear implant (CI) users. The spectral ripple resolution of recently implanted CI recipients (implanted during the last 10 years) were compared to those of CI recipients implanted 15 to 20 years ago, as well as those of normal-hearing and hearing-impaired listeners from previously published data from Henry, Turner, and Behrens [J. Acoust. Soc. Am. 118, 1111-1121 (2005)]. More recently, implanted CI recipients showed significantly better spectral ripple resolution. There is no significant difference in spectral ripple resolution for these recently implanted subjects compared to hearing-impaired (acoustic) listeners. The more recently implanted CI users had significantly better pre-operative speech perception than previously reported CI users. These better pre-operative speech perception scores in CI users from the current study may be related to better performance on the spectral ripple discrimination task; however, other possible factors such as improvements in internal and external devices cannot be excluded.

  9. Mechanical stability of immediately loaded implants with various surfaces and designs: a pilot study in dogs.

    Science.gov (United States)

    Neugebauer, Jörg; Weinländer, Michael; Lekovic, Vojislav; von Berg, Karl-Heinz Linne; Zoeller, Joachim E

    2009-01-01

    Immediate loading is among the most innovative techniques in implant therapy today. This pilot study investigates the biomechanical outcome of various designs and surfaces that claim to shorten implant treatment. In each quadrant of two mongrel dogs, four different implants were used for immediate loading. The following implants were placed 3 months after tooth extraction: screw with low thread profile and anodic oxidized surface (LPAOS), solid screw with wide thread profile and titanium plasma spray coating (WPTPS), screw with low profile and hybrid design of double-etched and machined surface (LPHES), and screw with two thread profiles and a sandblasted and acid-etched surface (DTSAE). The insertion torque of each implant was above 35 Ncm. Resonance frequency analysis was performed after implant placement and again after sacrifice. Additionally, the removal torque and the amount of embedded titanium particles in the peri-implant bone were measured. All 16 prostheses were functional after a 5-month loading period. The highest mean removal torque values were recorded with WPTPS implants (24.4 Ncm/mm), followed by DTSAE implants (22.3 Ncm/mm) and LPAOS implants (18.7 Ncm/mm); the lowest score was obtained by LPHES (12.0 Ncm/mm). The ISQ values increased between the time of surgery and recall for all systems on average, but a significant positive correlation was found for DTSAE only. Significantly higher amounts of titanium were found in the surrounding bone with WPTPS (0.76%) and LPAOS (0.41%) in comparison with DTSAE (0.10%) and LPHES (0.03%). Immediate loading is possible with various designs and surfaces if high primary stability can be achieved during implant placement.

  10. Hybrid processing of Ti-6Al-4V using plasma immersion ion implantation combined with plasma nitriding

    Directory of Open Access Journals (Sweden)

    Silva Maria Margareth da

    2006-01-01

    Full Text Available Based on the fact that the Ti-6Al-4V alloy has good mechanical properties, excellent resistance to corrosion and also excellent biocompatibility, however with low wear resistance, this work aims to test plasma processes or combination of plasma and ion implantation processes to improve these characteristics. Two types of processing were used: two steps PIII (Plasma Immersion Ion Implantation combined with PN (Plasma Nitriding and single step PIII treatment. According to Auger Electron Spectroscopy (AES results, the best solution was obtained by PIII for 150 minutes resulting in ~ 65 nm of nitrogen implanted layer, while the sample treated with PIII (75 minutes and PN (75 minutes reached ~ 35 nm implanted layer. The improvement of surface properties could also be confirmed by the nanoindentation technique, with values of hardness increasing for both processes. AFM (Atomic Force Microscopy characterization showed that the single step PIII process presented greater efficiency than the duplex process (PIII + PN, probably due to the sputtering occurring during the second step (PN removing partially the implanted layer of first step (PIII.

  11. Magnetic resonance imaging investigation of the bone conduction implant – a pilot study at 1.5 Tesla

    Science.gov (United States)

    Jansson, Karl-Johan Fredén; Håkansson, Bo; Reinfeldt, Sabine; Rigato, Cristina; Eeg-Olofsson, Måns

    2015-01-01

    Purpose The objective of this pilot study was to investigate if an active bone conduction implant (BCI) used in an ongoing clinical study withstands magnetic resonance imaging (MRI) of 1.5 Tesla. In particular, the MRI effects on maximum power output (MPO), total harmonic distortion (THD), and demagnetization were investigated. Implant activation and image artifacts were also evaluated. Methods and materials One implant was placed on the head of a test person at the position corresponding to the normal position of an implanted BCI and applied with a static pressure using a bandage and scanned in a 1.5 Tesla MRI camera. Scanning was performed both with and without the implant, in three orthogonal planes, and for one spin-echo and one gradient-echo pulse sequence. Implant functionality was verified in-between the scans using an audio processor programmed to generate a sequence of tones when attached to the implant. Objective verification was also carried out by measuring MPO and THD on a skull simulator as well as retention force, before and after MRI. Results It was found that the exposure of 1.5 Tesla MRI only had a minor effect on the MPO, ie, it decreased over all frequencies with an average of 1.1±2.1 dB. The THD remained unchanged above 300 Hz and was increased only at lower frequencies. The retention magnet was demagnetized by 5%. The maximum image artifacts reached a distance of 9 and 10 cm from the implant in the coronal plane for the spin-echo and the gradient-echo sequence, respectively. The test person reported no MRI induced sound from the implant. Conclusion This pilot study indicates that the present BCI may withstand 1.5 Tesla MRI with only minor effects on its performance. No MRI induced sound was reported, but the head image was highly distorted near the implant. PMID:26604836

  12. Implant Mandibular Overdentures Retained by Immediately Loaded Implants: A 1-Year Randomized Trial Comparing the Clinical and Radiographic Outcomes Between Mini Dental Implants and Standard-Sized Implants.

    Science.gov (United States)

    Zygogiannis, Kostas; Aartman, Irene Ha; Parsa, Azin; Tahmaseb, Ali; Wismeijer, Daniel

    The aim of this 1-year randomized trial was to evaluate and compare the clinical and radiographic performance of four immediately loaded mini dental implants (MDIs) and two immediately loaded standard-sized tissue-level (STL) implants, placed in the interforaminal region of the mandible and used to retain mandibular overdentures (IODs) in completely edentulous patients. A total of 50 completely edentulous patients wearing conventional maxillary dentures and complaining about insufficient retention of their mandibular dentures were divided into two groups; 25 patients received four MDIs and 25 patients received two STL implants. The marginal bone loss (MBL) at the mesial and distal sides of each implant was assessed by means of standardized intraoral radiographs after a period of 1 year. Implant success and survival rates were also calculated. Immediate loading was possible for all patients in the first group. In the second group, an immediate loading protocol could not be applied for 10 patients. These patients were treated with a delayed loading protocol. A mean MBL of 0.42 ± 0.56 mm for the MDIs and 0.54 ± 0.49 mm for the immediately loaded STL implants was recorded at the end of the evaluation period. There was no statistically significant difference between the MDIs and the immediately loaded STL implants. Two MDIs failed, resulting in a survival rate of 98%. The success rate was 91%. For the immediately loaded conventional implants, the survival rate was 100% and the success rate 96.7% after 1 year of function. However, in 10 patients, the immediate loading protocol could not be followed. Considering the limitations of this short-term clinical study, immediate loading of four unsplinted MDIs or two splinted STL implants to retain mandibular overdentures seems to be a feasible treatment option. The marginal bone level changes around the MDIs were well within the clinically acceptable range.

  13. Comparative study of the effects of photodynamic therapy and conventional therapy on ligature induced peri-implantitis in dogs

    International Nuclear Information System (INIS)

    Hayek, Ricardo Rada Ahmad

    2004-01-01

    Progressive peri-implanter bone losses, which are accompanied by inflammatory process in the soft tissues is referred to as peri-implantitis. The aim of this study was to compare the effects of lethal photosensitisation with the conventional technique on bacterial reduction in ligature induced peri-implantitis in dogs. Seventeen third pre-molars of Labrador dogs were extracted and, immediately after, the implants were submerged. After osteointegration, peri-implantitis was induced. After 4 months, ligature were removed and the same period was waited for natural induction of bacterial plaque. The dogs were randomly divided into two groups. In the conventional group, they were treated with the conventional techniques of mucoperiosteal flaps for scaling the implant surface and irrigate it. In the laser group, only mucoperiosteal scaling was carried out before photodynamic therapy. On the peri-implanter pocket an azulene paste was injected and a GaAlAs low-power laser (λ= 660 nm, P= 30 mW, E= 5,4 J and Δt= 3 min.). Microbiological samples were obtained before and immediately after treatment. One implant was removed to be analyzed by scan electron microscopy to verify contamination on the implant surface. The results of this study showed that Prevotella sp., Fusobacterium e S. Beta-haemolyticus were significantly reduced for the conventional and laser groups. (author)

  14. Effects of implantation temperature and thermal annealing on the Ga{sup +} ion beam induced optical contrast formation in a-SiC:H

    Energy Technology Data Exchange (ETDEWEB)

    Tsvetkova, T., E-mail: tania_tsvetkova@yahoo.co.uk [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); University of Exeter, College of Engineering, Mathematics and Physical Sciences, Harrison Building, North Park Rd, Exeter EX4 4QF (United Kingdom); Wright, C.D. [University of Exeter, College of Engineering, Mathematics and Physical Sciences, Harrison Building, North Park Rd, Exeter EX4 4QF (United Kingdom); Kitova, S. [Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, 109 Acad. G. Bontchev St., 1113 Sofia (Bulgaria); Bischoff, L. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 51 01 19, 01314 Dresden (Germany); Zuk, J. [Institute of Physics, Maria Curie-Sklodovska University, Pl. M.Curie-Sklodovskiej 1, 20-031 Lublin (Poland)

    2013-07-15

    The effects of implantation temperature and post-implantation thermal annealing on the Ga{sup +} ion beam induced optical contrast formation in hydrogenated silicon–carbon alloy films have been studied. As a result of the implantation a well-expressed “darkening” effect (i.e. absorption edge shift to the longer-wavelength/lower-photon-energy region) has been registered. It is accompanied by a remarkable increase of the absorption coefficient up to 2 orders of magnitude in the measured photon energy range (1.5–3.1 eV). The optical contrast thus obtained (between implanted and unimplanted regions of the film material) has been made use of in the form of optical pattern formation by computer-operated Ga{sup +}-focused ion beam. Possible applications of this effect in the area of submicron lithography and high-density optical data storage have been suggested with regard to the most widely spread focused micro-beam systems based on Ga{sup +} liquid metal ion sources. The fact that Ga has a very low melting point (T{sub m} = 29.8 °C) and an unusual feature of volume contraction on melting are factors which favour Ga incorporation upon ion-implantation as dispersed clusters, or small nanoparticles. It has been previously noted that Ga precipitation into nanoparticles can vary dramatically (in terms of particle size) with Ga concentration and small changes in surface implant temperature, thus affecting the optical properties of the target. The precise role of implantation temperature effects, i.e. the target temperature during Ga{sup +} ion irradiation, on the optical contrast obtainable, has been therefore a key part of this study. Appropriate post-implantation annealing treatments were also studied, since these are expected to offer further benefits in reducing the required ion dose and enhancing contrast, thus increasing the cost-effectiveness of the bit-writing method.

  15. Success of Unsplinted Implant-Retained Removable Mandibular and Maxillary Overdentures: A Retrospective Study of Consecutive Cases.

    Science.gov (United States)

    Strong, Samuel M

    2015-01-01

    Implant-retained overdentures have been provided on both splinted and freestanding implants. For the mandible, a long history shows that both approaches can be successful over the long term. For the maxilla, many clinicians prefer to splint the implants because of concerns about softer bone quality and insufficient data supporting the use of freestanding overdenture abutments. However, a few investigations have found survival rates for unsplinted maxillary overdentures to be comparable to those for splinted ones. The present study analyzed records of consecutive patients who were treated with unsplinted maxillary and mandibular overdentures and followed for 4 to 107 months. A total of 31 overdentures were identified, 15 maxillary and 16 mandibular, supported by 129 implants. All the overdentures, along with all the implants, survived throughout the follow-up period.

  16. Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

    DEFF Research Database (Denmark)

    Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

    2017-01-01

    OBJECTIVES: The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase and Cochrane library search......-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone...... loss around implants with a scalloped implant-abutment connection. CONCLUSIONS: A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must...

  17. COCHLEAR IMPLANTATION PREVALENCE IN ELDERLY

    Directory of Open Access Journals (Sweden)

    A. V. Starokha

    2014-01-01

    Full Text Available Current paper describes an experience of cochlear implantation in elderly. Cochlear implantation has become a widely accepted intervention in the treatment of individuals with severe-to-profound sensorineural hearing loss. Cochlear implants are now accepted as a standard of care to optimize hearing and subsequent speech development in children and adults with deafness. But cochlear implantation affects not only hearing abilities, speech perception and speech production; it also has an outstanding impact on the social life, activities and self-esteem of each patient. The aim of this study was to evaluate the cochlear implantation efficacy in elderly with severe to profound sensorineural hearing loss. There were 5 patients under our observation. Surgery was performed according to traditional posterior tympanotomy and cochleostomy for cochlear implant electrode insertion for all observed patients. The study was conducted in two stages: before speech processor’s activation and 3 months later. Pure tone free field audiometry was performed to each patient to assess the efficiency of cochlear implantation in dynamics. The aim of the study was also to evaluate quality of life in elderly with severe to profound sensorineural hearing loss after unilateral cochlear implantation. Each patient underwent questioning with 36 Item Short Form Health Survey (SF-36. SF-36 is a set of generic, coherent, and easily administered quality-of-life measures. The SF-36 consists of eight scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The eight sections are: physical functioning; physical role functioning; emotional role functioning; vitality; emotional well-being; social role functioning; bodily pain; general health perceptions. Our results demonstrate that cochlear implantation in elderly consistently improved quality of life

  18. Main facts 1993

    International Nuclear Information System (INIS)

    1994-01-01

    This report presents the main facts of the studies carried out by the Direction des Etudes et Recherches (DER) of Electricite de France: new applications of electricity, classical and nuclear thermal power plants, electrical equipment, environment protection, network analysis, information and informatic equipment

  19. Immediate Direct-To-Implant Breast Reconstruction Using Anatomical Implants

    Directory of Open Access Journals (Sweden)

    Sung-Eun Kim

    2014-09-01

    Full Text Available BackgroundIn 2012, a new anatomic breast implant of form-stable silicone gel was introduced onto the Korean market. The intended use of this implant is in the area of aesthetic breast surgery, and many reports are promising. Thus far, however, there have been no reports on the use of this implant for breast reconstruction in Korea. We used this breast implant in breast reconstruction surgery and report our early experience.MethodsFrom November 2012 to April 2013, the Natrelle Style 410 form-stable anatomically shaped cohesive silicone gel-filled breast implant was used in 31 breasts of 30 patients for implant breast reconstruction with an acellular dermal matrix. Patients were treated with skin-sparing mastectomies followed by immediate breast reconstruction.ResultsThe mean breast resection volume was 240 mL (range, 83-540 mL. The mean size of the breast implants was 217 mL (range, 125-395 mL. Breast shape outcomes were considered acceptable. Infection and skin thinning occurred in one patient each, and hematoma and seroma did not occur. Three cases of wound dehiscence occurred, one requiring surgical intervention, while the others healed with conservative treatment in one month. Rippling did not occur. So far, complications such as capsular contracture and malrotation of breast implant have not yet arisen.ConclusionsBy using anatomic breast implants in breast reconstruction, we achieved satisfactory results with aesthetics better than those obtained with round breast implants. Therefore, we concluded that the anatomical implant is suitable for breast reconstruction.

  20. Helium implanted AlHf as studied by 181 Ta TDPAC

    Indian Academy of Sciences (India)

    Measurements on helium implanted sample indicate the binding of helium associated defects by Hf solute clusters. Isochronal annealing measurements indicate the dissociation of the helium implantation induced defects from Hf solute clusters for annealing treatments beyond 650 K. On comparison of the present results ...

  1. Imunohistological aspects of the tissue around dental implants

    Science.gov (United States)

    Nimigean, Victor; Nimigean, Vanda R.; Sǎlǎvǎstru, Dan I.; Moraru, Simona; BuÅ£incu, Lavinia; Ivaşcu, Roxana V.; Poll, Alexandru

    2016-03-01

    Objectives: study of soft and hard tissues around implants. Material and methods: For the immunohistochemical and histological study of the implant/soft tissue interface, we examined pieces of peri-implant mucosa harvested from 35 patients. The implant/bone interface was assessed using histologic and histomorphometric examination of hard tissues around unloaded, early loaded or delayed loaded dental implants with pre-established design, with a sandblasted and acid-etched surface, placed both in extraction sockets, or after bone healing following tooth removal. This study was performed on 9 common race dogs. Results: The histological study of the implant/soft tissue interface showed regenerative modifications and moderate chronic subepithelial inflammatory reactions. Immunohistochemical evaluation of the soft tissue biopsies revealed the presence of specific immunocompetent cells and proteins of the matrix metalloproteinase (MMP) expression. Bone-implants contacts were more obvious in the apical half of the implants and at the edges of the threads, than between them. A mature, lamelliform bone containing lacunae with osteocytes and lack of connective tissue were noticed around implants that were late placed and loaded. The new-formed bone was also abundant in the crestal zone, not only in the apical part of the implants. Conclusions: A thorough understanding of the microstructure of dental implant/soft and hard tissue interface will improve the longevity of osseointegrated implants.

  2. Prevalence of Dental Implants and Evaluation of Peri-implant Bone Levels in Patients Presenting to a Dental School: A Radiographic Cross-Sectional 2-Year Study.

    Science.gov (United States)

    Alkan, Eylem Ayhan; Mau, Lian Ping; Schoolfield, John; Guest, Gary F; Cochran, David L

    To evaluate the number of patients with dental implants who present to a dental school clinic for screening and to report the prevalence of peri-implant bone level change detected on digital panoramic radiographs of those subjects. Patient screening files for 9,422 patients over a 2-year period were examined to see how many patients presented with dental implants. Those patients with at least one implant were further evaluated by measuring the bone level on the mesial and distal sides of the implant using the screening radiograph. A total of 187 patients (2%) had at least one implant. In regard to implants, 423 were examined and 146 (33%) had no detectable bone loss defined as bone level below the top of the implant. When thresholds of bone loss were evaluated, 109 implants (25%) had ≥ 2 mm of bone loss on either the mesial or distal sides or both. The median bone loss was 1.74 mm for the 277 implants with detectable bone loss and 2.97 mm for the 109 implants that had ≥ 2 mm bone loss. Interestingly, patients who were ≥ 70 years of age had significantly (P = .03) more bone loss in the mandible compared with the maxilla, while patients who were 60 to 69 years of age had significantly greater loss in the maxilla. These data reveal that for patients presenting to the dental school for a screening over a 2-year period, 1.98% had one or more dental implants. Furthermore, those patients with implants had a minimum amount of bone loss as measured from the top of the implant.

  3. Influence of Palatal Coverage and Implant Distribution on Denture Strain in Maxillary Implant Overdentures.

    Science.gov (United States)

    Takahashi, Toshihito; Gonda, Tomoya; Tomita, Akiko; Mizuno, Yoko; Maeda, Yoshinobu

    2016-01-01

    As maxillary implant overdentures are being increasingly used in clinical practice, prosthodontic complications related to these dentures are also reported more often. The purpose of this study was to examine the influence of palatal coverage and implant distribution on the shear strain of maxillary implant overdentures. A maxillary edentulous model with implants inserted in the anterior, premolar, and molar areas was fabricated. Two kinds of experimental overdentures, with and without palatal coverage, were also fabricated, and two strain gauges were attached at the midline of the labial and palatal sides. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the shear strain in each denture was compared by analysis of variance (P = .05). In all situations, the shear strain in palateless dentures was significantly higher than in dentures with palate on both sides (P overdentures exhibited much higher strain than overdentures with palate regardless of the implant distribution; this may cause more prosthodontic and implant complications. The most favorable configuration to prevent complications in maxillary implant overdentures was palatal coverage that was supported by more than four widely distributed implants.

  4. Bacterial colonization of the implant-abutment interface of conical connection with an internal octagon: an in vitro study using real-time PCR.

    Science.gov (United States)

    Baj, A; Beltramini, G A; Bolzoni, A; Cura, F; Palmieri, A; Scarano, A; Ottria, L; Giannì, A B

    2017-01-01

    Bacterial leakage at the implant-abutment connection of a two-piece implant system is considered the main cause of peri-implantitis. Prevention of bacterial leakage at the implant-abutment connection is mandatory for reducing inflammation process around implant neck and achieving bone stability. Micro-cavities at implant-abutment connection level can favour bacterial leakage, even in modern two-piece implant systems. The conical connection with an internal octagon (CCIO) is considered to be more stable mechanically and allows a more tight link between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new two-implant system with an internal conical implant-abutment connection with internal octagon (Shiner XT, FMD Falappa Medical Devices S.p.A. Rome, Italy). To verify the ability of the implant in protecting the internal space from the external environment, the passage of genetically modified Escherichia c oli across implant-abutment interface was evaluated. Four Shiner XT implants (FMD, Falappa Medical Devices®, Rome, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 6% for P. gingivalis and 5% for T. forsythia. Other comparable studies about the tightness of the tested implant system reported similar results. The gap size at the implant-abutment connection of CCIOs was measured by other authors discovering a gap size of 1–2μm of the AstraTech system and of 4μm for the Ankylos system. Bacterial leakage along implant-abutment connection of cylindrical and tapered implants, Shiner XT, (FMD Falappa Medical Devices S.p.A. Rome, Italy) showed better results compared to other implants. Additional studies are needed to explore the relationship in terms of

  5. Uneventful Anterior Migration of Intravitreal Ozurdex Implant in a Patient with Iris-Sutured Intraocular Lens and Descemet Stripping Automated Endothelial Keratoplasty

    Directory of Open Access Journals (Sweden)

    Andleeb Zafar

    2018-02-01

    Full Text Available Purpose: We report here the case of a patient with anterior segment migration of intravitreal dexamethasone implant as well as its management and outcome. Methods: The patient had the following sequence of events: complicated cataract surgery, iris-sutured intraocular lens implant, followed by cystoid macular edema treated with intravitreal Avastin, retinal vein occlusion treated with intravitreal dexamethasone implant, corneal decompensation treated with Descemet stripping automated endothelial keratoplasty (DSAEK, and finally recurrence of macular edema treated with repeated intravitreal dexamethasone implant. Results: Dexamethasone implant had completely dissolved from the eye 12 weeks after insertion without any complication. Conclusion: A conservative approach with regular monitoring in the situation of a quiet anterior segment without any corneal decompensation can provide enough time for the implant to dissolve without causing any complication to the involved eye, avoiding any additional surgical intervention, as presented in this case report. Despite the fact that the implant was left for natural dissolution, there were no adverse effects related to the graft or the eye.

  6. A speech processing study using an acoustic model of a multiple-channel cochlear implant

    Science.gov (United States)

    Xu, Ying

    1998-10-01

    A cochlear implant is an electronic device designed to provide sound information for adults and children who have bilateral profound hearing loss. The task of representing speech signals as electrical stimuli is central to the design and performance of cochlear implants. Studies have shown that the current speech- processing strategies provide significant benefits to cochlear implant users. However, the evaluation and development of speech-processing strategies have been complicated by hardware limitations and large variability in user performance. To alleviate these problems, an acoustic model of a cochlear implant with the SPEAK strategy is implemented in this study, in which a set of acoustic stimuli whose psychophysical characteristics are as close as possible to those produced by a cochlear implant are presented on normal-hearing subjects. To test the effectiveness and feasibility of this acoustic model, a psychophysical experiment was conducted to match the performance of a normal-hearing listener using model- processed signals to that of a cochlear implant user. Good agreement was found between an implanted patient and an age-matched normal-hearing subject in a dynamic signal discrimination experiment, indicating that this acoustic model is a reasonably good approximation of a cochlear implant with the SPEAK strategy. The acoustic model was then used to examine the potential of the SPEAK strategy in terms of its temporal and frequency encoding of speech. It was hypothesized that better temporal and frequency encoding of speech can be accomplished by higher stimulation rates and a larger number of activated channels. Vowel and consonant recognition tests were conducted on normal-hearing subjects using speech tokens processed by the acoustic model, with different combinations of stimulation rate and number of activated channels. The results showed that vowel recognition was best at 600 pps and 8 activated channels, but further increases in stimulation rate and

  7. Unrecoverable bi-products of drilling titanium alloy and tantalum metal implants: a pilot study.

    Science.gov (United States)

    Skowronek, Paweł; Olszewski, Paweł; Święszkowski, Wojciech; Synder, Marek; Sibiński, Marcin; Mazek, Jacek

    2018-05-01

    Trabecular metal implants with a porous architecture that allows for the incorporation of bone into the implant during healing are gaining popularity in alloplastic revision procedures. The bi-products of drilling titanium alloy (Ti) and tantalum (Ta) implants have not been previously assessed. Four holes were drilled in each of two spatially porous trabecular implants, one Ta and the other Ti alloy (Ti-6Al-7Nb), for this pilot in vitro study. The particles were flushed out with a continuous flow of saline. The particles' weight and the volume were then measured using a Radwag XA 110/2X (USA) laboratory balance. The total volume of the obtained metal fines was measured by titration using a 10 mm 3 measurement system. A cobalt carbide bit was used since the holes could not be made with a standard bone drill. Each Ti and Ta implant lost 1.26 g and 2.48 g of mass, respectively. The volume of free particles recovered after each stage was 280 mm 3 and 149 mm 3 , respectively. Approximately 0.6% of the total implant mass was not recovered after drilling (roughly 2% of the mass of the particles created by drilling), despite the use of 5 µm filters. It is technically difficult to drill holes in Ti and Ta implants using standard surgical tools. The drilling process creates a considerable amount of metal particles, which cannot be recovered despite intensive flushing. This may have an adverse influence on the bio-functionality (survival) of the endoprosthesis and present deleterious systemic consequences.

  8. The influence of implant-abutment connection to peri-implant bone loss: A systematic review and meta-analysis.

    Science.gov (United States)

    Caricasulo, Riccardo; Malchiodi, Luciano; Ghensi, Paolo; Fantozzi, Giuliano; Cucchi, Alessandro

    2018-05-15

    Different implant-abutment connections are available and it has been claimed they could have an effect on marginal bone loss. The aim of this review is to establish if implant connection configuration influences peri-implant bone loss (PBL) after functional loading. A specific question was formulated according to the Population, Intervention, Control, and Outcome (PICO): Does the type of implant-abutment connection (external, internal, or conical) have an influence on peri-implant bone loss? A PubMed/MEDLINE electronic search was conducted to identify English language publications published in international journals during the last decade (from 2006 to 2016). The search was conducted by using the Medical Subject Headings (MeSH) keywords "dental implants OR dental abutment AND external connection OR internal connection OR conical connection OR Morse Taper." Selected studies were randomized clinical trials and prospective studies; in vitro studies, case reports and retrospective studies were excluded. Titles and abstracts and, in the second phase, full texts, were evaluated autonomously and in duplicate by two reviewers. A total of 1649 articles were found, but only 14 studies met the pre-established inclusion criteria and were considered suitable for meta-analytic analysis. The network meta-analysis (NMA) suggested a significant difference between the external and the conical connections; this was less evident for the internal and conical ones. Platform-switching (PS) seemed to positively affect bone levels, non-regarding the implant-connection it was applied to. Within the limitations of this systematic review, it can be concluded that crestal bone levels are better maintained in the short-medium term when internal kinds of interface are adopted. In particular, conical connections seem to be more advantageous, showing lower peri-implant bone loss, but further studies are necessary to investigate the efficacy of implant-abutment connection on stability of crestal

  9. Salivary Concentration of Oxidative Stress Biomarkers in a Group of Patients with Peri-Implantitis: A Transversal Study.

    Science.gov (United States)

    Sánchez-Siles, Mariano; Lucas-Azorin, Javier; Salazar-Sánchez, Noemi; Carbonell-Meseguer, Luis; Camacho-Alonso, Fabio

    2016-10-01

    The purpose of this study was to know if peri-implantitis causes an increase in the total salivary concentration of oxidative stress markers. Seventy patients, 28 men and 42 women, 60 of them with dental implants, 30 of which had peri-implantitis and 30 were healthy. The remaining 10 were the control group: healthy subjects without implants. The average number of implants per patient was 4.70 ± 2.29 in the peri-implantitis group and 2 70 ± 2.11 in the control group. Periodontal/peri-implant variables were assessed, including bleeding index, gingival index, clinical attachment level, probing depth, presence of pockets larger than 4 and 6 mm, pain to percussion, suppuration, gingival hyperplasia or granuloma, crestal bone loss (both mesially and distally), evaluated through periapical radiography. Saliva samples from the 70 subjects were collected for measurement of malondialdehyde high performance liquid chromatography (HPLC) and myeloperoxidase (enzyme-linked immunosorbent assay analysis) concentrations. Implants affected with peri-implantitis had an average follow-up of 26.40 ± 7.97 months. 4.12% of implants with peri-implantitis had a painful response to percussion. 2.06% showed suppuration; 25.77% had granuloma. The mean crestal bone loss in implants wtih peri-implantitis was 3.78 ± 1.17 mm. Total salivary malondialdehyde concentration in the peri-implantitis group (0.52 ± 0.37 μM/l) was slightly higher than that in the group with healthy implants (0.40 ± 0.16 μM/l) and also slightly higher than that in the group of healthy patients without implants (0.41 ± 0.79 μM/l), although the difference was not statistically significant, p value = .442. Myeloperoxidase concentration was slightly higher in the peri-implantitis group (12.32 ± 2.17 ng/ml) than in the group with healthy implants (11.54 ± 2.80 ng/ml) and the group of healthy patients without implants (11.86 ± 2.67 ng/ml), without

  10. Study of the mineralization of coral implanted in vivo by radioactive tracers

    International Nuclear Information System (INIS)

    Irigaray, J.L.; Sauvage, T.; Oudadesse, H.; El Fadl, H.

    1993-01-01

    Coral may be used as a substitution biomaterial to the bone graft, due to its physico-chemical and architectural properties. The coral, after its implantation 'in vivo' reaches a mineral composition and crystalline structure comparable to those of a bone. The calcification mechanism of this implant is studied using 45 Ca as radioactive tracer. The atomic elements contained in the initial coral were analysed in function of the time spent in the body, by marking the calcium and the strontium contained in its structure. (K.A.) 8 refs.; 6 figs.; 4 tabs

  11. Bone-Implant Contact around Crestal and Subcrestal Dental Implants Submitted to Immediate and Conventional Loading

    Directory of Open Access Journals (Sweden)

    Ana Emília Farias Pontes

    2014-01-01

    Full Text Available The present study aims to evaluate the influence of apicocoronal position and immediate and conventional loading in the percentage of bone-implant contact (BIC. Thus, 36 implants were inserted in the edentulous mandible from six dogs. Three implants were installed in each hemimandible, in different positions in relation to the ridge: Bone Level (at crestal bone level, Minus 1 (one millimeter apical to crestal bone, and Minus 2 (two millimeters apical to crestal bone. In addition, each hemimandible was submitted to a loading protocol: immediate (prosthesis installed 24 hours after implantation or conventional (prosthesis installed 120 days after implantation. Ninety days after, animals were killed, and implant and adjacent tissues were prepared for histometric analysis. BIC values from immediate loaded implants were 58.7%, 57.7%, and 51.1%, respectively, while conventional loaded implants were 61.8%, 53.8%, and 68.4%. Differences statistically significant were not observed among groups (P=0.10, ANOVA test. These findings suggest that different apicocoronal positioning and loading protocols evaluated did not interfere in the percentage of bone-implant contact, suggesting that these procedures did not jeopardize osseointegration.

  12. Helium implanted RAFM steels studied by positron beam Doppler Broadening and Thermal Desorption Spectroscopy

    International Nuclear Information System (INIS)

    Carvalho, I; Schut, H; Fedorov, A; Luzginova, N; Desgardin, P; Sietsma, J

    2013-01-01

    Reduced Activation Ferritic/Martensitic steels are being extensively studied because of their foreseen application in fusion and Generation IV fission reactors. To mimic neutron irradiation conditions, Eurofer97 samples were implanted with helium ions at energies of 500 keV and 2 MeV and doses of 5x10 15 -10 16 He /cm 2 , creating atomic displacements in the range 0.07–0.08 dpa. The implantation induced defects were characterized by positron beam Doppler Broadening (DB) and Thermal Desorption Spectroscopy (TDS). The DB data could be fitted with one or two layers of material, depending on the He implantation energy. The S and W values obtained for the implanted regions suggest the presence of not only vacancy clusters but also positron traps of the type present in a sub-surface region found on the reference sample. The traps found in the implanted layers are expected to be He n V m clusters. For the 2 MeV, 10 16 He/cm 2 implanted sample, three temperature regions can be observed in the TDS data. Peaks below 450 K can be ascribed to He released from vacancies in the neighbourhood of the surface, the phase transition is found at 1180 K and the peak at 1350 K is likely caused by the migration of bubbles.

  13. Fracaso en los implantes dentales: Fibrointegración. Reporte de caso clínico

    Directory of Open Access Journals (Sweden)

    Iris Luz Santís Chamorro

    2014-06-01

    Full Text Available  ResumenLa rehabilitación con implantes dentales en los pacientes con edentulismo parcial o total posee amplias indicaciones que se ven limitadas por factores anatómicos y biológicos. La oseointegración surge como un hecho descubierto entre la adaptación biológica del hueso a la superficie del titanio del implante (interfase hueso-implante por lo que se afirma que el motivo de fracaso de la mayoría de los sistemas de implantes es que éstos se encapsulen en un tejido de cicatrización fibroso (fibrointegración mal diferenciado lo que crea movilidad, que lleva a reacciones en la mucosa y finalmente a la pérdida. El objetivo del presente artículo es promover la presentación de casos clínicos de pacientes con fracaso de implantes dentales, con el ánimo de esclarecer las posibles causas y los factores coadyuvantes de dicho fracaso, y así mejorar los resultados en implantología. (Duazary 2008; 115-120AbstractThe rehabilitation with dental implants in the patients with partial absence or total of teeth possesses extensive indications that are seen limited by biological and anatomical factors. The oseointegration arises like a discovered fact among the biological adaptation of the bone to the surface of the titanic of the implant (interface bone-implant for which it is affirmed that the motive of failure of the majority of the systems of implants is that these it self envelop in a scar formation of fibrous tissue (Fibrointegration badly differentiated what creates mobility, that carries to reactions in the mucous membrane and finally to the loss. The objective of the present article is to promote the presentation of patients' clinical cases with failure of dental implants, with the intention of clarifying the possible reasons and the helping factors of the above mentioned failure, and this way to improve the results in implantology.Key Words: Fibrointegration; oseointegration; dentals implants; interface; implants failure.

  14. Implant damage and redistribution of indium in indium-implanted thin silicon-on-insulator

    International Nuclear Information System (INIS)

    Chen Peng; An Zhenghua; Zhu Ming; Fu, Ricky K.Y.; Chu, Paul K.; Montgomery, Neil; Biswas, Sukanta

    2004-01-01

    The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10 14 cm -2 ) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure

  15. Immediate loading of mandibular overdentures supported by one-piece, direct metal laser sintering mini-implants: a short-term prospective clinical study.

    Science.gov (United States)

    Mangano, Francesco G; Caprioglio, Alberto; Levrini, Luca; Farronato, Davide; Zecca, Piero A; Mangano, Carlo

    2015-02-01

    Only a few studies have dealt with immediately loaded, unsplinted mini-implants supporting ball attachment-retained mandibular overdentures (ODs). The aim of this study is to evaluate treatment outcomes of ball attachment-retained mandibular ODs supported by one-piece, unsplinted, immediately loaded, direct metal laser sintering (DMLS) mini-implants. Over a 4-year period (2009 to 2012), all patients referred to the Dental Clinic, University of Varese, and to a private practice for treatment with mandibular ODs were considered for inclusion in this study. Each patient received three or four DMLS mini-implants. Immediately after implant placement, a mandibular OD was connected to the implants. At each annual follow-up session, clinical and radiographic parameters were assessed, including the following outcome measures: 1) implant failures; 2) peri-implant marginal bone loss; and 3) complications. Statistical analysis was conducted using a life-table analysis. A total of 231 one-piece DMLS mini-implants were inserted in 62 patients. After 4 years of loading, six implants failed, giving an overall cumulative survival rate of 96.9%. The mean distance between the implant shoulder and the first visible bone-to-implant contact was 0.38 ± 0.25 and 0.62 ± 0.20 mm at the 1- and 4-year follow-up examinations, respectively. An incidence of 6.0% of biologic complications was reported; prosthetic complications were more frequent (12.9%). Within the limits of this study, it can be concluded that the immediate loading of one-piece, unsplinted, DMLS titanium mini-implants by means of ball attachment-supported mandibular ODs is a successful treatment procedure. Long-term follow-up studies are needed to confirm these results.

  16. Dental Implants and General Dental Practitioners of Nepal: A study of existing knowledge and need for further education

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    Bhageshwar Dhami

    2017-03-01

    Full Text Available Background & Objectives: The use of dental implants in partially or completely edentulous patients has proved effective and an accepted treatment modality with predictable long-term success. Dental implants are becoming a popular choice for replacing the missing teeth because of increased awareness about implants both in dentists and patients. The objective of the study was to assess the basic knowledge and education about dental implants among general dental practitioners (GDPs of Nepal.Materials & Methods:  A cross sectional questionnaire was carried out among 110 GDPs which consist of twenty questions that were divided into three categories; first with some basic knowledge in implant dentistry, second with clinical knowledge of dental implants and third with dental implant education and training.Results: Out of 110 GDPs, 72.7% had basic knowledge about implant dentistry and 65.5% were not aware about advance surgical procedures like sinus lift and guided bone regeneration. All the GDPs were positive regarding more training and education in dental implants and 95.5% of them would like to incorporate dental implant treatment in their practice in future. Conclusion: GDPs should have adequate knowledge and training of dental implants which can be incorporated at undergraduate or post doctoral level so that they are skilled to provide quality dental implant therapy to their patients confidently.

  17. Retrograde peri-implantitis

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    Mohamed Jumshad

    2010-01-01

    Full Text Available Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation.

  18. Study of low energy hydrogen ion implantation effects in silicon: electric properties

    International Nuclear Information System (INIS)

    Barhdadi, A.

    1985-07-01

    Several analysis methods have been developed: hydrogen distribution analysis by nuclear reaction, crystal disorder evaluation by R.B.S., chemical impurities identification by SIMS, optical measurements, electrical characterization of surface barriers, deep level spectroscopy DLTS, ... All these analyses have been made after implantation then after thermal annealing. A model explaining the effect of implantation then after thermal annealing. A model explaining the effect of implanted hydrogen is proposed, the implantation creates an important quantity of defects in a thin layer near the surface; a chemical attack removes them. In Schottky devices, this layer has a basic role on carrier transport phenomena. Other results are given, some of them allow to give an account of the passivation by hydrogen implantation [fr

  19. Implant Optimisation for Primary Hip Replacement in Patients over 60 Years with Osteoarthritis: A Cohort Study of Clinical Outcomes and Implant Costs Using Data from England and Wales.

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    Simon S Jameson

    Full Text Available Hip replacement is one of the most commonly performed surgical procedures worldwide; hundreds of implant configurations provide options for femoral head size, joint surface material and fixation method with dramatically varying costs. Robust comparative evidence to inform the choice of implant is needed. This retrospective cohort study uses linked national databases from England and Wales to determine the optimal type of replacement for patients over 60 years undergoing hip replacement for osteoarthritis.Implants included were the commonest brand from each of the four types of replacement (cemented, cementless, hybrid and resurfacing; the reference prosthesis was the cemented hip procedure. Patient reported outcome scores (PROMs, costs and risk of repeat (revision surgery were examined. Multivariable analyses included analysis of covariance to assess improvement in PROMs (Oxford hip score, OHS, and EQ5D index (9159 linked episodes and competing risks modelling of implant survival (79,775 procedures. Cost of implants and ancillary equipment were obtained from National Health Service procurement data.EQ5D score improvements (at 6 months were similar for all hip replacement types. In females, revision risk was significantly higher in cementless hip prostheses (hazard ratio, HR = 2.22, p<0.001, when compared to the reference hip. Although improvement in OHS was statistically higher (22.1 versus 20.5, p<0.001 for cementless implants, this small difference is unlikely to be clinically important. In males, revision risk was significantly higher in cementless (HR = 1.95, p = 0.003 and resurfacing implants, HR = 3.46, p<0.001, with no differences in OHS. Material costs were lowest with the reference implant (cemented, range £1103 to £1524 and highest with cementless implants (£1928 to £4285. Limitations include the design of the study, which is intrinsically vulnerable to omitted variables, a paucity of long-term implant survival data (reflecting the

  20. The clinical and diagnostic consequences of Poly Implant Prothèse silicone breast implants, recalled from the European market in 2010.

    Science.gov (United States)

    Maijers, Maria C; Niessen, Francisus B

    2013-03-01

    Recently, Poly Implant Prothèse silicone breast implants were recalled from the European market. The authors studied 112 women and previously published data on rupture prevalence. Women are presenting with symptoms they feel may be a result of ruptured implants. The authors' aim was to study the clinical consequences of Poly Implant Prothèse implants. One hundred twelve women with 224 proven Poly Implant Prothèse implants after 10 years of implantation were enrolled in this study. All women underwent physical examination and magnetic resonance imaging and were interviewed regarding symptoms. Details of the explantations of 35 women with at least one ruptured implant were documented. Tissue from 10 women was sent for pathologic investigation. Of 112 women, 34 (30.4 percent) had symptoms attributable to their implants. Physical examination showed that 12 of the 121 women (10.7 percent) had findings suggestive of rupture, most commonly pain. Three had lymphadenopathy that seemed to correlate with implant rupture or excessive "gel bleed." Pathologic findings showed no malignancies. Eight women who underwent explantation had no implant rupture. Excessive gel bleed was documented in half of them. Clinical consequences of women with Poly Implant Prothèse implants are comparable to those reported in the literature of other manufacturers. Neither complaints nor findings at physical examination had a significant correlation with implant rupture at explantation. Magnetic resonance imaging is still the preferred method compared with physical examination for diagnosing rupture. The low specificity was probably caused by the difficulty in differentiating between rupture and excessive gel bleed in these implants.

  1. Soft Tissue Esthetics in Implant Dentistry

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    Rakesh V. Somanathan

    2007-01-01

    Full Text Available Dental implants have been considered to be a successful treatment modality. Recently, achieving a good osseointegration is not the ultimate goal for the restorative dentist. Successful implant treatment demands the best gingival esthetic success along with stability and function of the implant. This study was performed to obtain answers to some controversial points pertaining to esthetics and function of implants in maxilla. Immediate flapless implantation into the extraction sockets in maxillary anterior zone is an emerging treatment option in dentistry- the esthetic success of which was in debate for long. The proposed study compared the esthetic success of immediate flapless implants (ILA, to immediate implants with the need for flap (ILB and, delayed implants (DSL in single tooth restorations, in the anterior region of the maxilla. The other aim of the study was to find out if any relation exists between the interproximal crestal bone height and papilla height. Analysis was done irrespective of treatment procedure in the same study group using periodontal sounding and radiographs to find out the relation. From the study involving 106 participants, including 21 ILA, 22 ILB and 63 DSL cases, we received highest papillary index score of 2.6 average from group ILA, followed by ILB and DSL, after 3 months of prosthetic loading. From the periodontal sounding and radiographic study it was evident that, when the distance between the base of the contact point of crowns and height of interproximal bone was less than 5, the papilla was present 100 % of the time, but when the distance increased to 6 and more than 7 mm, the papilla was present only 46.5 and 24 percentage of the time respectively.

  2. Two-generation reproductive toxicity study of implanted depleted uranium (DU) in CD rats.

    Science.gov (United States)

    Arfsten, D P; Still, K R; Wilfong, E R; Johnson, E W; McInturf, S M; Eggers, J S; Schaeffer, D J; Bekkedal, M Y-V

    2009-01-01

    Depleted uranium (DU) munitions and armor plating have been used in several conflicts over the last 17 yr, including the Persian Gulf War and the Iraq War. Because of its effectiveness and availability, DU will continue to be used in military applications into the foreseeable future. There is much controversy over the use of DU in weapons and equipment because of its potential radiological and toxic hazards, and there is concern over the chronic adverse health effects of embedded DU shrapnel in war veterans and bystanders. This study evaluated the effects of long-term implantation of DU on the reproductive success of F0 generation adults and development and survival of subsequent F1 and F2 generations in a two-generation reproductive toxicity study. F0 generation Sprague-Dawley rats, 8 wk of age, were surgically implanted with 0, 4, 8, 12, or 20 DU pellets (1 x 2 mm). Inert implant control animals were implanted with 12 or 20 tantallum (Ta) pellets. The F0 generation was then mated at 120 d post DU implantation. In the F0 generation, when measured on postimplantation d 27 and 117, uranium was present in the urine of DU-implanted animals in a dose-dependent manner. F0 reproductive success was similar across treatment groups and the maternal retrieval test revealed no changes in maternal behavior. DU implantation exerted no effect on the survival, health, or well-being of the F0 generation. Necropsy results of F0 animals were negative with the exception of a marked inflammatory response surrounding the implanted DU pellets. For the F1 generation, measures of F1 development through postnatal day (PND) 20 were unremarkable and no gross abnormalities were observed in F1 offspring. No uranium was detected in whole-body homogenates of PND 4 or PND 20 pups. Necropsy findings of F1 PND 20 pups were negative and no instances of ribcage malformation were observed in F1 PND 20 pups. Body weight and body weight gain of F1 rats through PND 120 were similar across treatment

  3. Immediate occlusal loading of implants in the partially edentate mandible: a prospective 1-year radiographic and 4-year clinical study.

    Science.gov (United States)

    Ostman, Pär-Olov; Hellman, Mats; Sennerby, Lars

    2008-01-01

    The purpose of the present prospective clinical study was to evaluate the radiographic and clinical outcome of immediately loaded implants in the partial edentulous mandible over a 4-year follow-up period using a modified surgical protocol, primary implant stability criteria, and splinting for inclusion. Patients in need of implant treatment in the partial edentate mandible were consecutively included in the study. The implant sites were underprepared to obtain maximal stability. Inclusion criteria for the study were torque of a least 30 Ncm before final seating of the implant and an ISQ greater than 60. A provisional fixed partial denture was delivered within 24 hours and a definitive fixed partial denture within 3 months. The patients were monitored with clinical and radiographic follow-up examinations for up to 4 years. Stability of the implants was measured with resonance frequency analysis at placement and after 6 months. Ninety-six patients were evaluated, and 77 patients who met the inclusion criteria were included. A total of 111 fixed partial dentures supported by 257 Brånemark System implants (77 turned and 180 TiUnite implants) were delivered. Four (1.6%) of the 257 implants did not osseointegrate, giving an overall survival rate of 98.4% after 4 years. Three turned (3.9%) implants and 1 oxidized implant (0.6%) failed after 4 to 13 months. The average marginal bone resorption was 0.7 mm (SD 0.78) during the first year in function. Turned implants showed an average bone loss of 0.5 mm (SD 0.8) and oxidized implants an average of 0.7 mm (SD 0.8). Resonance frequency analysis showed a mean implant stability quotient of 72.2 (SD 7.5) at placement and 72.5 (SD 5.7) after 6 months of loading. It is concluded that immediate loading of implants with firm primary stability in partially edentulous areas of the mandible appears to be a viable procedure with predictable outcome.

  4. Nanomechanical properties of bone around cement-retained abutment implants. A minipig study

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    R.R.M. de Barros

    2016-06-01

    Full Text Available Aim The nanomechanical evaluation can provide additional information about the dental implants osseointegration process. The aim of this study was to quantify elastic modulus and hardness of bone around cemented-retained abutment implants positioned at two different crestal bone levels. Materials and methods The mandibular premolars of 7 minipigs were extracted. After 8 weeks, 8 implants were inserted in each animal: crestally on one side of the mandible and subcrestally on the other (crestal and subcrestal groups. Functional loading were immediately provided with abutments cementation and prostheses installation. Eight weeks later, the animals euthanasia was performed and nanoindentation analyses were made at the most coronal newly formed bone region (coronal group, and below in the threaded region (threaded group of histologic sections. Results The comparisons between subcrestal and crestal groups did not achieve statistical relevance; however the elastic modulus and hardness levels were statistically different in the two regions of evaluation (coronal and threaded. Conclusions The crestal and subcrestal placement of cement-retained abutment implants did not affect differently the nanomechanical properties of the surrounding bone. However the different regions of newly formed bone (coronal and threaded groups were extremely different in both elastic modulus and hardness, probably reflecting their differences in bone composition and structure.

  5. A noninterventional study documenting use and success of implants with a new chemically modified titanium surface in daily dental practice.

    Science.gov (United States)

    Luongo, Giuseppe; Oteri, Giacomo

    2010-01-01

    A new chemically modified titanium surface, SLActive, has recently been developed. The results obtained in controlled clinical trials indicate that this implant can be safely used and that it offers predictable results. The goal of this noninterventional study was to verify that the success rates of implants used in daily dental practice are comparable to those reported in controlled clinical trials. This study was a prospective, noninterventional study using implants with a chemically modified surface according to the daily dental practice procedures applied by private practitioners. The choice of the implantation procedure and the loading protocol were the responsibility of the investigator and were chosen according to the patient's needs. Thirty clinical centers actively participated in this study, and 226 patients were treated, of which, 8 patients were lost to follow-up. Because of the noninterventional design of the study, the patients were not selected according to strictly defined inclusion/exclusion criteria. Thus, the study included individuals with risk factors such as smoking (24%), untreated gingivitis or periodontitis (9%), and bruxism (6%). The implants were equally distributed between mandible (46%) and maxilla (54%). A bone augmentation procedure was done in 31% of the cases. Early loading (functional loading between 48 hours and 3 months after implant insertion) was applied most frequently (48%), followed by the conventional loading protocol (3 to 6 months after implant placement, 34%). Immediate restoration and immediate loading were rare (7% and 2%, respectively). Of 276 implants inserted and documented, 5 implants failures were reported, all of which were associated with a sinus floor augmentation procedure. The survival rate was 98.2% at the 1-year follow-up visit. The results showed that implants with a chemically modified surface can be successfully restored with success rates similar to those reported in formal clinical trials under more

  6. Immediate Implant Placement in Single-Tooth Molar Extraction Sockets: A 1- to 6-Year Retrospective Clinical Study.

    Science.gov (United States)

    Amato, Francesco; Polara, Giorgio

    The aim of this study was to investigate the survival rate of implants immediately placed in fresh extraction sockets of molars in the maxilla and mandible with a single-stage procedure. A total of 102 patients were treated, and 107 implants (53 in the maxilla and 54 in the mandible) were placed in a fresh molar extraction socket and connected to a healing abutment. After a mean follow-up of 3 years (range: 1 to 6 years) 1 implant failed, for a cumulative success rate of 99.06% (98.11% for the mandible and 100% for the maxilla). The results of this study support placement of an implant immediately after the extraction of a molar, applying a single-stage procedure.

  7. In vitro studies of nanosilver-doped titanium implants for oral and maxillofacial surgery

    Directory of Open Access Journals (Sweden)

    Pokrowiecki R

    2017-06-01

    Full Text Available Rafał Pokrowiecki,1,2 Tomasz Zaręba,3 Barbara Szaraniec,4 Krzysztof Pałka,5 Agnieszka Mielczarek,6 Elżbieta Menaszek,7 Stefan Tyski3,8 1Center for Cranio-Maxillo-Facial Surgery, Voivodeship Children’s Hospital, Olsztyn, 2Department of Oral Surgery, Jagiellonian Medical University, Kraków, 3Department of Antibiotics and Microbiology, National Medicines Institute, Warsaw, 4Faculty of Material Science and Ceramics, AGH University of Science and Technology, Kraków, 5Department of Materials Engineering, Lublin University of Technology, Lublin, 6Department of Conservative Dentistry, Medical University of Warsaw, Warsaw, 7Department of Cytobiology, Collegium Medicum, Jagiellonian University, Kraków, 8Department of Pharmaceutical Microbiology, Medical University of Warsaw, Warsaw, Poland Abstract: The addition of an antibacterial agent to dental implants may provide the opportunity to decrease the percentage of implant failures due to peri-implantitis. For this purpose, in this study, the potential efficacy of nanosilver-doped titanium biomaterials was determined. Titanium disks were incorporated with silver nanoparticles over different time periods by Tollens reaction, which is considered to be an eco-friendly, cheap, and easy-to-perform method. The surface roughness, wettability, and silver release profile of each disc were measured. In addition, the antibacterial activity was also evaluated by using disk diffusion tests for bacteria frequently isolated from the peri-implant biofilm: Streptococcus mutans, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguis, Porphyromonas gingivalis, Staphylococcus aureus, and Escherichia coli. Cytotoxicity was evaluated in vitro in a natural human osteoblasts cell culture. The addition of nanosilver significantly increased the surface roughness and decreased the wettability in a dose-dependent manner. These surfaces were significantly toxic to all the tested bacteria following a 48-hour exposure

  8. Follow-up of cochlear implant use in patients who developed bacterial meningitis following cochlear implantation.

    Science.gov (United States)

    Mancini, Patrizia; D'Elia, Chiara; Bosco, Ersilia; De Seta, Elio; Panebianco, Valeria; Vergari, Valeria; Filipo, Roberto

    2008-08-01

    The present study is a long-term follow-up of speech perception outcomes and cochlear implant use in three cases of meningitis that occurred after cochlear implantation. Case series study. Study was performed on three children implanted with different models of Clarion devices, two of them with positioner. Recognition and comprehension were assessed via the Italian adaptation of GASP (TAP) test, and phonetically balanced bi-syllabic words in open-set. High resolution computed tomography scan acquisition was performed to obtain axial coronal and oblique multiplanar reconstructions of the cochlea. Two patients were affected by enlarged cochlear acqueduct and Mondini malformation the first carrying positioner. One patient had a normal cochlea, and the positioner could have been the main cause of bacterial spread. As a consequence of meningitis the child with normal cochlea and the other with enlarged vestibular acqueduct developed cochlear ossification, increased M-level and worsening of hearing outcomes. The child with Mondini malformation developed facial nerve stimulation. Contralateral implantation was performed in the first two patients. Bacterial meningitis occurring after cochlear implantation may induce cochlear ossification, facial nerve stimulation, and permanent or temporary loss of implant use. Planned follow-up with high resolution computed tomography and evaluation of M-levels could be useful prognostic tools in the management of these patients.

  9. Failure analysis of fractured dental zirconia implants.

    Science.gov (United States)

    Gahlert, M; Burtscher, D; Grunert, I; Kniha, H; Steinhauser, E

    2012-03-01

    The purpose of the present study was the macroscopic and microscopic failure analysis of fractured zirconia dental implants. Thirteen fractured one-piece zirconia implants (Z-Look3) out of 170 inserted implants with an average in situ period of 36.75±5.34 months (range from 20 to 56 months, median 38 months) were prepared for macroscopic and microscopic (scanning electron microscopy [SEM]) failure analysis. These 170 implants were inserted in 79 patients. The patient histories were compared with fracture incidences to identify the reasons for the failure of the implants. Twelve of these fractured implants had a diameter of 3.25 mm and one implant had a diameter of 4 mm. All fractured implants were located in the anterior side of the maxilla and mandibula. The patient with the fracture of the 4 mm diameter implant was adversely affected by strong bruxism. By failure analysis (SEM), it could be demonstrated that in all cases, mechanical overloading caused the fracture of the implants. Inhomogeneities and internal defects of the ceramic material could be excluded, but notches and scratches due to sandblasting of the surface led to local stress concentrations that led to the mentioned mechanical overloading by bending loads. The present study identified a fracture rate of nearly 10% within a follow-up period of 36.75 months after prosthetic loading. Ninety-two per cent of the fractured implants were so-called diameter reduced implants (diameter 3.25 mm). These diameter reduced implants cannot be recommended for further clinical use. Improvement of the ceramic material and modification of the implant geometry has to be carried out to reduce the failure rate of small-sized ceramic implants. Nevertheless, due to the lack of appropriate laboratory testing, only clinical studies will demonstrate clearly whether and how far the failure rate can be reduced. © 2011 John Wiley & Sons A/S.

  10. Evaluation on the movement of endosseous titanium implants under continuous orthodontic forces: an experimental study in the dog.

    Science.gov (United States)

    Hsieh, Yao-Dung; Su, Ching-Ming; Yang, Yi-Hsin; Fu, Earl; Chen, Hui-Lin; Kung, Suefang

    2008-06-01

    The purpose of this study was to evaluate the movement of pure titanium implants under different continuous forces in the edentulous alveolar ridge. Four pairs of titanium implants were inserted into the right maxillary and mandibular post-extraction edentulous ridge of the experimental dog. Three different levels of continuous force (100, 200, and 500 g) were loaded onto three pairs of adjacent implant abutments using a memory Ni-Ti coil spring for up to 6 months and the remaining two implant abutments as the control group received no force. The positions of implant abutments were observed and the distances between the implants abutment at the top, middle and base levels were measured at the 0th, 2nd, 3rd, 6th and 8th month of the follow-up period. There was no significant change in the distances between adjacent abutments loaded with 100 or 200 g continuous forces throughout the entire study period. However, significantly more movement of implant abutments was noted in the 500 g pair after the 3rd month of loading when compared with the 200 or the 100 g pair (both P < 0.001). This change further increased at the 6th month (P < 0.001, 0.01, respectively). Moreover, the difference in the measurements at the top, middle and base level indicated that the two adjacent implants moved in a tipping manner in the 500 g pair after 3 and 6 months of loading. The osseointegrated implants remained stable and rigid with a pulling force of 100 and 200 g after 6 months of loading. However, when the force reached 500 g, the implants moved in an inward-tipping pattern. The results suggested that endosseous titanium implants might not necessarily be rigid anchorages under all circumstances.

  11. Monitoring the osseointegration process in porous Ti6Al4V implants produced by additive manufacturing: an experimental study in sheep.

    Science.gov (United States)

    Kayacan, Mehmet C; Baykal, Yakup B; Karaaslan, Tamer; Özsoy, Koray; Alaca, İlker; Duman, Burhan; Delikanlı, Yunus E

    2018-04-01

    This study investigated the design and osseointegration process of transitive porous implants that can be used in humans and all trabecular and compact bone structure animals. The aim was to find a way of forming a strong and durable tissue bond on the bone-implant interface. Massive and transitive porous implants were produced on a direct metal laser sintering machine, surgically implanted into the skulls of sheep and kept in place for 12 weeks. At the end of the 12-week period, the Massive and porous implants removed from the sheep were investigated by scanning electron microscopy (SEM) to monitor the osseointegration process. In the literature, each study has selected standard sizes for pore diameter in the structures they use. However, none of these involved transitional porous structures. In this study, as opposed to standard pores, there were spherical or elliptical pores at the micro level, development channels and an inner region. Bone cells developed in the inner region. Transitive pores grown gradually in accordance with the natural structure of the bone were modeled in the inner region for cells to develop. Due to this structure, a strong and durable tissue bond could be formed at the bone-implant interface. Osseointegration processes of Massive vs. porous implants were compared. It was observed that cells were concentrated on the surface of Massive implants. Therefore, osseointegration between implant and bone was less than that of porous implants. In transitive porous implants, as opposed to Massive implants, an outer region was formed in the bone-implant interface that allowed tissue development.

  12. A preliminary biomechanical study of a novel carbon-fibre hip implant versus standard metallic hip implants.

    Science.gov (United States)

    Bougherara, Habiba; Zdero, Rad; Dubov, Anton; Shah, Suraj; Khurshid, Shaheen; Schemitsch, Emil H

    2011-01-01

    Total hip arthroplasty is a widespread surgical approach for treating severe osteoarthritis of the human hip. Aseptic loosening of standard metallic hip implants due to stress shielding and bone loss has motivated the development of new materials for hip prostheses. Numerically, a three-dimensional finite element (FE) model that mimicked hip implants was used to compare a new hip stem to two commercially available implants. The hip implants simulated were a novel CF/PA12 carbon-fibre polyamide-based composite hip stem, the Exeter hip stem (Stryker, Mahwah, NJ, USA), and the Omnifit Eon (Stryker, Mahwah, NJ, USA). A virtual axial load of 3 kN was applied to the FE model. Strain and stress distributions were computed. Experimentally, the three hip stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. Axial loads of 3 kN were applied. Measurements of axial stiffness and strain were taken and compared to FE analysis. The overall linear correlation between FE model versus experimental strains showed reasonable results for the lines-of-best-fit for the Composite (Pearson R(2)=0.69, slope=0.82), Exeter (Pearson R(2)=0.78, slope=0.59), and Omnifit (Pearson R(2)=0.66, slope=0.45), with some divergence for the most distal strain locations. From FE analysis, the von Mises stress range for the Composite stem was much lower than that in the Omnifit and Exeter implants by 200% and 45%, respectively. The preliminary experiments showed that the Composite stem stiffness (1982 N/mm) was lower than the metallic hip stem stiffnesses (Exeter, 2460 N/mm; Omnifit, 2543 N/mm). This is the first assessment of stress, strain, and stiffness of the CF/PA12 carbon-fibre hip stem compared to standard commercially-available devices. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

  13. Implantation of P ions in SiO2 layers with embedded Si nanocrystals

    International Nuclear Information System (INIS)

    Kachurin, G.A.; Cherkova, S.G.; Volodin, V.A.; Kesler, V.G.; Gutakovsky, A.K.; Cherkov, A.G.; Bublikov, A.V.; Tetelbaum, D.I.

    2004-01-01

    The effect of 10 13 -10 16 cm -2 P ions implantation and of subsequent annealing on Si nanocrystals (Si-ncs), formed preliminarily in SiO 2 layers by the ion-beam synthesis, has been studied. Photoluminescence (PL), Raman spectroscopy, high resolution electron microscopy (HREM), X-Ray Photoelectron Spectroscopy (XPS) and optical absorption were used for characterizations. The low fluence implantations have shown even individual displacements in Si-ncs quench their PL. Restoration of PL from partly damaged Si-ncs proceeds at annealing less than 1000 deg. C. In the low fluence implanted and annealed samples an increased Si-ncs PL has been found and ascribed to the radiation-induced shock crystallization of stressed Si nanoprecipitates. Annealing at temperatures under 1000 deg. C are inefficient when P ion fluences exceed 10 14 cm -2 , thus becoming capable to amorphize Si-ncs. High crystallization temperature of the amorphized Si-ncs is attributed to a counteraction of their shell layers. After implantation of the highest P fluences an enhanced recovery of PL was found from P concentration over 0.1 at.%. Raman spectroscopy and HREM showed an increased Si-ncs number in such layers. The effect resembles the impurity-enhanced crystallization, known for heavily doped bulk Si. This effect, along with the data obtained by XPS, is considered as an indication P atoms are really present inside the Si-ncs. However, no evidence of free electrons appearance has been observed. The fact is explained by an increased interaction of electrons with the donor nuclei in Si-ncs

  14. The biocompatibility of SLA-treated titanium implants

    International Nuclear Information System (INIS)

    Kim, Hyeongil; Choi, Seong-Ho; Ryu, Jae-Jun; Koh, Seung-Yong; Park, Ju-Han; Lee, In-Seop

    2008-01-01

    The titanium implant surface was sandblasted with large grits and acid etched (SLA) to increase the implant surface for osseointegration. The topography of the titanium surface was investigated with scanning electron microscopy (SEM) and a profilometer. The SLA implant demonstrated uniform small micro pits (1-2 μm in diameter). The values of average roughness (R a ) and maximum height (R t ) were 1.19 μm and 10.53 μm respectively after sandblasting and the acid-etching treatment. In the cell-surface interaction study, the human osteoblast cells grew well in vitro. The in vivo evaluation of the SLA implant placed in rabbit tibia showed good bone-to-implant contact (BIC) with a mean value of 29% in total length of the implant. In the short-term clinical study, SLA implants demonstrated good clinical performance, maintaining good crestal bone height

  15. One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study.

    Science.gov (United States)

    Siddiqi, A; Duncan, W J; De Silva, R K; Zafar, S

    2016-01-01

    Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) ( p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) ( p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions.

  16. In-vivo evaluation of the kinematic behavior of an artificial medial meniscus implant: A pilot study using open-MRI.

    Science.gov (United States)

    De Coninck, Tineke; Elsner, Jonathan J; Linder-Ganz, Eran; Cromheecke, Michiel; Shemesh, Maoz; Huysse, Wouter; Verdonk, René; Verstraete, Koenraad; Verdonk, Peter

    2014-09-01

    In this pilot study we wanted to evaluate the kinematics of a knee implanted with an artificial polycarbonate-urethane meniscus device, designed for medial meniscus replacement. The static kinematic behavior of the implant was compared to the natural medial meniscus of the non-operated knee. A second goal was to evaluate the motion pattern, the radial displacement and the deformation of the meniscal implant. Three patients with a polycarbonate-urethane implant were included in this prospective study. An open-MRI was used to track the location of the implant during static weight-bearing conditions, within a range of motion of 0° to 120° knee flexion. Knee kinematics were evaluated by measuring the tibiofemoral contact points and femoral roll-back. Meniscus measurements (both natural and artificial) included anterior-posterior meniscal movement, radial displacement, and meniscal height. No difference (P>0.05) was demonstrated in femoral roll-back and tibiofemoral contact points during knee flexion between the implanted and the non-operated knees. Meniscal measurements showed no significant difference in radial displacement and meniscal height (P>0.05) at all flexion angles, in both the implanted and non-operated knees. A significant difference (P ≤ 0.05) in anterior-posterior movement during flexion was observed between the two groups. In this pilot study, the artificial polycarbonate-urethane implant, indicated for medial meniscus replacement, had no influence on femoral roll-back and tibiofemoral contact points, thus suggesting that the joint maintains its static kinematic properties after implantation. Radial displacement and meniscal height were not different, but anterior-posterior movement was slightly different between the implant and the normal meniscus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Hip Implant Systems

    Science.gov (United States)

    ... Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Hip implants are medical devices intended to restore mobility ...

  18. The vestibular implant: Quo vadis?

    Directory of Open Access Journals (Sweden)

    Raymond eVan De Berg

    2011-08-01

    Full Text Available AbstractObjective: to assess the progress of the development of the vestibular implant and its feasibility short-term. Data sources: a search was performed in Pubmed, Medline and Embase. Key words used were vestibular prosth* and vestibular implant. The only search limit was language: English or Dutch. Additional sources were medical books, conference lectures and our personal experience with per-operative vestibular stimulation in patients selected for cochlear implantation.Study selection: all studies about the vestibular implant and related topics were included and evaluated by two reviewers. No study was excluded since every study investigated different aspects of the vestibular implant. Data extraction and synthesis: data was extracted by the first author from selected reports, supplemented by additional information, medical books conference lectures. Since each study had its own point of interest with its own outcomes, it was not possible to compare data of different studies. Conclusion: to use a basic vestibular implant in humans seems feasible in the very near future. Investigations show that electric stimulation of the canal nerves induces a nystagmus which corresponds to the plane of the canal which is innervated by the stimulated nerve branch. The brain is able to adapt to a higher baseline stimulation, while still reacting on a dynamic component. The best response will be achieved by a combination of the optimal stimulus (stimulus profile, stimulus location, precompensation, complemented by central vestibular adaptation. The degree of response will probably vary between individuals, depending on pathology and their ability to adapt.

  19. Comparative study between unilateral and bilateral cochlear implantation in children of 1 and 2 years of age.

    Science.gov (United States)

    Escorihuela García, Vicente; Pitarch Ribas, María Ignacia; Llópez Carratalá, Ignacio; Latorre Monteagudo, Emilia; Morant Ventura, Antonio; Marco Algarra, Jaime

    2016-01-01

    The studies that have evaluated the effectiveness of bilateral cochlear implantation in children suggest an improvement in hearing about sound localization and speech discrimination. In this paper we show the differences in audio-linguistic achievements with early bilateral cochlear implantation versus unilateral, and differences between simultaneous and sequential bilateral implantation. We present 88 children with bilateral profound sensorineural hearing loss, treated with bilateral cochlear implantation in 32 cases and unilateral in 56 cases, during the first 12 months (27 children) of life and between 12 and 24 months (61 children). We conducted a statistical comparison of both groups in the audiometry, IT-Mais, Nottingham, LittlEars scales and verbal tests. No significant differences in hearing thresholds and questionnaires between unilateral and bilateral implantation were detected in either the first or second year. Verbal tests do show statistically significant differences: children with bilateral cochlear implant obtain 100% recognition of disyllabic and phrases within 2-3 years after implantation whilst children with one implant do not obtain those results at 5 years after surgery. No differences between simultaneous and sequential bilateral implantation were detected. We emphasize the importance of ensuring good early audiological screening, to carry out an early and bilateral cochlear implantation with the consequent development of audio-language skills similar to normal hearing children. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

  20. Application of triple-crystal diffractometry for study of ion implanted layer defects

    International Nuclear Information System (INIS)

    Shcherbachev, K.D.; Bublik, V.T.

    2000-01-01

    Application of a triple-crystal arrangement, unlike traditionally used double-crystal one, allowed one to separate coherent and incoherent scattering components and to improve a resolution significantly. Advantages of the triple-crystal X-ray diffractometry to study defects in ion-implanted layers are demonstrated by example of characterisation of Si-GaAs(100) wafers doped by Si + with energy of 50 keV and does of 1x10 15 and 1x10 14 cm -2 . To explain a behaviour of point defects after implantation and annealing the analysis of strain depth profile was used. Two processes are shown to play a key role in formation of the distorted layer during implantation. The first one is an annihilation of Frenkel pairs components that decreases the total point defects concentration. Another one is a sink of more mobile interstitials to the surface that leads to formation of the thin subsurface layer enriched by vacancies [ru

  1. Congenitally Deafblind Children and Cochlear Implants

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup

    2008-01-01

    There has been much research conducted demonstrating the positive benefits of cochlear implantation (CI) in children who are deaf. Research on cochlear implantation in children who are both deaf and blind, however, is lacking. The purpose of this article is to present a study of 5 congenitally...... deafblind children who received cochlear implants between 2.2 and 4.2 years of age.  Ratings of video observations were used to measure the children's early communication development with and without the use of their cochlear implants. In addition, parental interviews were used to assess the benefits...... parents perceived regarding their children's cochlear implants. Two examples are included in this article to illustrate the parents' perspectives about cochlear implantation in their deafblind children. Benefits of cochlear implantation in this cohort of children included improved attention and emotional...

  2. Influence of Age on Clinical Performance of Mandibular Two-Implant Overdentures : A 10-Year Prospective Comparative Study

    NARCIS (Netherlands)

    Hoeksema, Arie R.; Visser, Anita; Raghoebar, Gerry M.; Vissink, Arjan; Meijer, Henny J. A.

    Purpose: The aim of this prospective comparative study was to assess whether age has influence on peri-implant health in patients treated with mandibular two-implant overdentures during a 10-year evaluation period. Materials and Methods: A prospective study was carried out with two groups of

  3. Study of the mineralization of coral implanted in vivo by radioactive tracers

    International Nuclear Information System (INIS)

    Irigaray, J.L.; Sauvage, T.; Oudadesse, H.; El Fadl, H.; Lefaivre, J.; Barlet, J.P.; Trevers, S.; Tixer, H.

    1993-01-01

    Coral has been used for the last ten years as bone substitution in the body because of its mechanical and osteoconductor properties. Primary studies have shown, for the first time, the quantitative behaviour of the atomic components. A biocoral implanted 'in vivo' was studied by some physical method of analysis. The natural biocorals used are the calcium carbonated exoskeletons built by Madrepian coral polyps. Neutron activation analysis showed that initial coral, essentially CaCO 3 , becomes a new material which has a mineral composition close to that of bone. The calcification mechanism of this implant was studied by using radioactive tracers. The tracer kinetics of calcium biomaterial have been established in the blood circuit and its use was shown by the organism for skeleton mineralization. (author) 8 refs.; 6 figs.; 4 tabs

  4. Facts about Glaucoma

    Science.gov (United States)

    ... Information » Glaucoma » Facts About Glaucoma Listen Facts About Glaucoma This information was developed by the National Eye ... is the best person to answer specific questions. Glaucoma Defined What is Glaucoma? Glaucoma is a group ...

  5. Audiovisual segregation in cochlear implant users.

    Directory of Open Access Journals (Sweden)

    Simon Landry

    Full Text Available It has traditionally been assumed that cochlear implant users de facto perform atypically in audiovisual tasks. However, a recent study that combined an auditory task with visual distractors suggests that only those cochlear implant users that are not proficient at recognizing speech sounds might show abnormal audiovisual interactions. The present study aims at reinforcing this notion by investigating the audiovisual segregation abilities of cochlear implant users in a visual task with auditory distractors. Speechreading was assessed in two groups of cochlear implant users (proficient and non-proficient at sound recognition, as well as in normal controls. A visual speech recognition task (i.e. speechreading was administered either in silence or in combination with three types of auditory distractors: i noise ii reverse speech sound and iii non-altered speech sound. Cochlear implant users proficient at speech recognition performed like normal controls in all conditions, whereas non-proficient users showed significantly different audiovisual segregation patterns in both speech conditions. These results confirm that normal-like audiovisual segregation is possible in highly skilled cochlear implant users and, consequently, that proficient and non-proficient CI users cannot be lumped into a single group. This important feature must be taken into account in further studies of audiovisual interactions in cochlear implant users.

  6. Increased crown-to-implant ratio may not be a risk factor for dental implant failure under appropriate plaque control.

    Science.gov (United States)

    Okada, Shinsuke; Koretake, Katsunori; Miyamoto, Yasunari; Oue, Hiroshi; Akagawa, Yasumasa

    2013-01-01

    The aim of this study was to evaluate whether increased crown-to-implant (C/I) ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control. Five male Beagle-Labrador hybrid dogs (2 years old) were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week). Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically. Implant stability quotient (ISQ) increased with time in all 3 groups, without any significant correlation with the C/I value (p >0.05). Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p >0.05). Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control. These findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

  7. Increased crown-to-implant ratio may not be a risk factor for dental implant failure under appropriate plaque control.

    Directory of Open Access Journals (Sweden)

    Shinsuke Okada

    Full Text Available OBJECTIVE: The aim of this study was to evaluate whether increased crown-to-implant (C/I ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control. MATERIALS AND METHODS: Five male Beagle-Labrador hybrid dogs (2 years old were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week. Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically. RESULT: Implant stability quotient (ISQ increased with time in all 3 groups, without any significant correlation with the C/I value (p >0.05. Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p >0.05. Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control. CONCLUSION: These findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

  8. Influence of implant number on the movement of mandibular implant overdentures.

    Science.gov (United States)

    Oda, Ken; Kanazawa, Manabu; Takeshita, Shin; Minakuchi, Shunsuke

    2017-03-01

    The rotational movement of an implant overdenture (IOD) has a negative effect on the perceived masticatory ability of the denture wearer. However, the influence of implant number on the movement of IODs has not been investigated. The purpose of this in vitro study was to evaluate the denture movement of mandibular IODs anchored by different numbers of implants. An edentulous mandibular test model with artificial mucosa and 5 experimental overdentures (N=5) was fabricated. The locator attachment system with blue nylon inserts was chosen for this study. Three implant positions were prepared: anterior midline (1-IOD), bilateral lateral incisor regions (2-IOD), and anterior midline and bilateral canine regions (3-IOD). Vertical loads of 50 N were applied to the mid-anterior region, the left canine region, the left premolar region, and the left first molar region. The vertical and horizontal displacements at the right distal edge and the vertical displacements at the loading point were measured. The displacement values were statistically analyzed using a 1-way analysis of variance and the post hoc Tukey honest significant difference test with the implant number as a factor. In addition, the values of the vertical and horizontal displacements at the distal edge of the overdenture were statistically compared using a paired t test, and the values of the vertical displacement at the distal edge of the overdenture were statistically analyzed by a repeated measures analysis of variance and the post hoc Tukey honest significance difference test with the loading point as a factor (a=.05). Upon anterior loading, the 2-IOD showed significantly larger vertical displacements at the right distal edge than the 1-IOD or 3-IOD (P.05). Within the limitations of this in vitro study, the following conclusions were drawn: During mastication with the anterior teeth, the use of 2 implants for anchoring an IOD increased the rotation of the denture base more than the use of 1 or 3 implants

  9. Marginal bone-level alterations of loaded zirconia and titanium dental implants: an experimental study in the dog mandible.

    Science.gov (United States)

    Thoma, Daniel S; Benic, Goran I; Muñoz, Fernando; Kohal, Ralf; Sanz Martin, Ignacio; Cantalapiedra, Antonio G; Hämmerle, Christoph H F; Jung, Ronald E

    2016-04-01

    The aim was to test whether or not the marginal bone-level alterations of loaded zirconia implants are similar to the bone-level alterations of a grade 4 titanium one-piece dental implant. In six dogs, all premolars and the first molars were extracted in the mandible. Four months later, three zirconia implants (BPI, VC, ZD) and a control titanium one-piece (STM) implant were randomly placed in each hemimandible and left for transmucosal healing (baseline). Six months later, CAD/CAM crowns were cemented. Sacrifice was scheduled at 6-month postloading. Digital X-rays were taken at implant placement, crowns insertion, and sacrifice. Marginal bone-level alterations were calculated, and intra- and intergroup comparisons performed adjusted by confounding factors. Implants were successfully placed. Until crown insertion, two implants were fractured (one VC, one ZD). At sacrifice, 5 more implants were (partly) fractured (one BPI, four ZD), and one lost osseointegration (VC). No decementation of crowns occurred. All implant systems demonstrated a statistically significant (except VC) loss of marginal bone between baseline and crown insertion ranging from 0.29 mm (VC; P = 0.116) to 0.80 mm (ZD; P = 0.013). The estimated marginal bone loss between baseline and 6 months of loading ranged between 0.19 mm (BPI) and 1.11 mm (VC), being statistically significant for STM and VC only (P implants and control implants (STM vs. BPI P = 0.007; vs. VC P = 0.001; vs. ZD P = 0.011). Zirconia implants were more prone to fracture prior to and after loading with implant-supported crowns compared to titanium implants. Individual differences and variability in the extent of the bone-level changes during the 12-month study period were found between the different implant types and materials. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Comparison of marginal bone loss between internal- and external-connection dental implants in posterior areas without periodontal or peri-implant disease.

    Science.gov (United States)

    Kim, Dae-Hyun; Kim, Hyun Ju; Kim, Sungtae; Koo, Ki-Tae; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul

    2018-04-01

    The purpose of this retrospective study with 4-12 years of follow-up was to compare the marginal bone loss (MBL) between external-connection (EC) and internal-connection (IC) dental implants in posterior areas without periodontal or peri-implant disease on the adjacent teeth or implants. Additional factors influencing MBL were also evaluated. This retrospective study was performed using dental records and radiographic data obtained from patients who had undergone dental implant treatment in the posterior area from March 2006 to March 2007. All the implants that were included had follow-up periods of more than 4 years after loading and satisfied the implant success criteria, without any peri-implant or periodontal disease on the adjacent implants or teeth. They were divided into 2 groups: EC and IC. Subgroup comparisons were conducted according to splinting and the use of cement in the restorations. A statistical analysis was performed using the Mann-Whitney U test for comparisons between 2 groups and the Kruskal-Wallis test for comparisons among more than 2 groups. A total of 355 implants in 170 patients (206 EC and 149 IC) fulfilled the inclusion criteria and were analyzed in this study. The mean MBL was 0.47 mm and 0.15 mm in the EC and IC implants, respectively, which was a statistically significant difference ( P <0.001). Comparisons according to splinting (MBL of single implants: 0.34 mm, MBL of splinted implants: 0.31 mm, P =0.676) and cement use (MBL of cemented implants: 0.27 mm, MBL of non-cemented implants: 0.35 mm, P =0.178) showed no statistically significant differences in MBL, regardless of the implant connection type. IC implants showed a more favorable bone response regarding MBL in posterior areas without peri-implantitis or periodontal disease.

  11. Dynamics of soft tissue healing at implants and teeth: a study in a dog model.

    Science.gov (United States)

    Sukekava, Flávia; Pannuti, Claudio M; Lima, Luiz A; Tormena, Mariana; Araújo, Mauricio G

    2016-05-01

    The aim of this study was to describe and to compare some characteristics of the soft tissue healing process around teeth and implants after flap surgery. Five adult beagle dogs had their third and fourth lower premolars extracted. After 3 months, four implants per dog were placed on the healed alveolar ridge and allowed to heal non-submerged during 3 months. After 3 months, four regions characterized by one implant and one adjacent tooth were identified in each dog. One region was randomly selected and soft tissue ressective flap surgery was performed at its buccal aspect. The remaining three regions were randomly treated in an identical manner, and the dogs were sacrificed to provide biopsies representing healing intervals of 1, 2, 4, and 12 weeks. The biopsies were prepared for histological and morphological analyses. Morphometric and histometric analyses have shown that the gingival tissues surrounding teeth were completely healed after a 4-week interval. However, it took from 4 to 12 weeks for the peri-implant mucosa to heal completely. The healing process around teeth and implants follows a similar sequence of events. Nevertheless, the complete process of healing and maturation of the peri-implant tissues takes longer than around teeth. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Magnetic resonance imaging investigation of the bone conduction implant – a pilot study at 1.5 Tesla

    Directory of Open Access Journals (Sweden)

    Fredén Jansson KJ

    2015-10-01

    Full Text Available Karl-Johan Fredén Jansson,1 Bo Håkansson,1 Sabine Reinfeldt,1 Cristina Rigato,1 Måns Eeg-Olofsson2 1Department of Signals and Systems, Chalmers University of Technology, 2Deptartment of Otorhinolaryngology Head and Neck Surgery, Sahlgrenska University Hospital, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Purpose: The objective of this pilot study was to investigate if an active bone conduction implant (BCI used in an ongoing clinical study withstands magnetic resonance imaging (MRI of 1.5 Tesla. In particular, the MRI effects on maximum power output (MPO, total harmonic distortion (THD, and demagnetization were investigated. Implant activation and image artifacts were also evaluated.Methods and materials: One implant was placed on the head of a test person at the position corresponding to the normal position of an implanted BCI and applied with a static pressure using a bandage and scanned in a 1.5 Tesla MRI camera. Scanning was performed both with and without the implant, in three orthogonal planes, and for one spin-echo and one gradient-echo pulse sequence. Implant functionality was verified in-between the scans using an audio processor programmed to generate a sequence of tones when attached to the implant. Objective verification was also carried out by measuring MPO and THD on a skull simulator as well as retention force, before and after MRI.Results: It was found that the exposure of 1.5 Tesla MRI only had a minor effect on the MPO, ie, it decreased over all frequencies with an average of 1.1±2.1 dB. The THD remained unchanged above 300 Hz and was increased only at lower frequencies. The retention magnet was demagnetized by 5%. The maximum image artifacts reached a distance of 9 and 10 cm from the implant in the coronal plane for the spin-echo and the gradient-echo sequence, respectively. The test person reported no MRI induced sound from the implant.Conclusion: This pilot study indicates that the present BCI

  13. Alveolar Ridge Contouring with Free Connective Tissue Graft at Implant Placement: A 5-Year Consecutive Clinical Study.

    Science.gov (United States)

    Hanser, Thomas; Khoury, Fouad

    2016-01-01

    This study evaluated volume stability after alveolar ridge contouring with free connective tissue grafts at implant placement in single-tooth gaps. A total of 52 single-tooth gaps with labial volume deficiencies in the maxilla (incisors, canines, and premolars) were consecutively treated with implants and concomitant free palatal connective tissue grafts in 46 patients between 2006 and 2009. Implants had to be covered with at least 2 mm peri-implant local bone after insertion. At implant placement, a free connective tissue graft from the palate was fixed inside a labial split-thickness flap to form an existing concave buccal alveolar ridge contour due to tissue volume deficiency into a convex shape. Standardized volumetric measurements of the labial alveolar contour using a template were evaluated before connective tissue grafting and at 2 weeks, 1 year, and 5 years after implantprosthetic incorporation. Tissue volume had increased significantly (P tissue contour of the implant before connective tissue grafting to baseline (2 weeks after implant-prosthetic incorporation). Statistically, 50% of the reference points (P > .05) kept their volume from baseline to 1 year after prosthetic incorporation and from baseline to 5 years after prosthetic incorporation, respectively, whereas reference points located within the area of the implant sulcus showed a significant (P connective tissue grafting appears to be an appropriate long-term means to contour preexisting buccal alveolar volume deficiencies in single implants.

  14. Optimization of dental implantation

    Science.gov (United States)

    Dol, Aleksandr V.; Ivanov, Dmitriy V.

    2017-02-01

    Modern dentistry can not exist without dental implantation. This work is devoted to study of the "bone-implant" system and to optimization of dental prostheses installation. Modern non-invasive methods such as MRI an 3D-scanning as well as numerical calculations and 3D-prototyping allow to optimize all of stages of dental prosthetics. An integrated approach to the planning of implant surgery can significantly reduce the risk of complications in the first few days after treatment, and throughout the period of operation of the prosthesis.

  15. Titanium Implant Impairment and Surrounding Muscle Cell Death Following High-Salt Diet: An In Vivo Study.

    Directory of Open Access Journals (Sweden)

    Mathieu Lecocq

    Full Text Available High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation program similar to that currently used in human care following arthroplasty.After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation.Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.

  16. Do textured breast implants decrease the rate of capsular contracture compared to smooth implants?

    Science.gov (United States)

    Cifuentes, Ignacio; Dagnino, Bruno; Rada, Gabriel

    2017-08-31

    The use of breast implants for aesthetic and reconstructive purposes has become one of the most common procedures performed by plastic surgeons. Several breast implants models exist. They differ in their size, filling, shape and characteristic of the shell, which can be smooth or textured. Capsular contracture is one of the main complications of breast implants. It has been suggested that the use of textured implants could reduce the incidence of capsular contracture. To answer this question, we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We identified 15 studies overall, of which 13 were randomized trials relevant for the question of interest. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. We concluded the use of textured breast implants probably decreases the risk of capsular contracture, however, they might be associated to an increased risk of anaplastic large cell lymphoma.

  17. [Significance of various implantate localizations of Sparks prostheses, experimental studies in rats].

    Science.gov (United States)

    Brieler, H S; Parwaresch, R; Thiede, A

    1976-01-01

    Our investigations show that Sparks prostheses after subcutaneous implantation are suitable for vascular grafting. At the end of the organization period the connective tissue becomes strong, and after the third and fourth weeks collagenous and elastic fibers can be seen. Ten weeks after s.c. implantation, collagenous fibers predominate. After this the Sparks prostheses can be used as a vascular graft. Intraperitoneal implantation, however, shows a histologically different picture with characteristic findings: only fat cells can be observed, a strong granulation tissue with elastic and collagenous fibers is not present. After intraperitoneal implantation Sparks prostheses are therefore unsuitable for vascular grafts.

  18. Study of thermal treated a-Si implanted with Er and O ions

    CERN Document Server

    Plugaru, R; Piqueras, J; Tate, T J

    2002-01-01

    Visible luminescence of amorphous silicon layers either implanted with Er or co-implanted with Er and O and subsequently annealed in nitrogen has been investigated by cathodoluminescence (CL) in a scanning electron microscope. Co-implanted samples show a more intense luminescence, which is revealed by annealing at lower temperatures than the samples implanted only with erbium. Thermal treatments cause the formation of erbium oxide as well as Er-Si complexes or precipitates. Violet-blue luminescence has been found from CL images and spectra to be related to Er-Si precipitates. Emission in the green-red range is attributed to oxide species.

  19. Study in mutation of alfalfa genome DNA due to low energy N+ implantation using RAPD

    International Nuclear Information System (INIS)

    Chen Roulei; Song Daojun; Yu Zengliang; Li Yufeng; Liang Yunzhang

    2001-01-01

    After implanted by various dosage N + beams, germination rate of alfalfa seeds appears to be saddle line with dosage increasing. The authors have studied in mutation of genome DNA due to low energy N + implantation, and concluded that 30 differential DNA fragments have been amplified by 8 primers (S 41 , S 42 , S 45 , S 46 , S 50 , S 52 , S 56 , S 58 ) in 100 primers, moreover, number of differential DNA fragments between CK and treatments increases with dosage. Consequently, low energy ion implantation can cause mutation of alfalfa genome DNA. The more dosage it is, the more mutation alfalfa will be

  20. Effects of pore size, implantation time, and nano-surface properties on rat skin ingrowth into percutaneous porous titanium implants.

    Science.gov (United States)

    Farrell, Brad J; Prilutsky, Boris I; Ritter, Jana M; Kelley, Sean; Popat, Ketul; Pitkin, Mark

    2014-05-01

    The main problem of percutaneous osseointegrated implants is poor skin-implant integration, which may cause infection. This study investigated the effects of pore size (Small, 40-100 μm and Large, 100-160 μm), nanotubular surface treatment (Nano), and duration of implantation (3 and 6 weeks) on skin ingrowth into porous titanium. Each implant type was percutaneously inserted in the back of 35 rats randomly assigned to seven groups. Implant extrusion rate was measured weekly and skin ingrowth into implants was determined histologically after harvesting implants. It was found that all three types of implants demonstrated skin tissue ingrowth of over 30% (at week 3) and 50% (at weeks 4-6) of total implant porous area under the skin; longer implantation resulted in greater skin ingrowth (p skin integration with the potential for a safe seal. Copyright © 2013 Wiley Periodicals, Inc.

  1. In vivo bioactivity of titanium and fluorinated apatite coatings for orthopaedic implants: a vibrational study

    Science.gov (United States)

    Taddei, Paola; Tinti, Anna; Reggiani, Matteo; Monti, Patrizia; Fagnano, Concezio

    2003-06-01

    The bone integration of implants is a complex process which depends on chemical composition and surface morphology. To accelerate osteointegration, metal implants are coated with porous metal or apatites which have been reported to increase mineralisation, improving prosthesis fixation. To study the influence of composition and morphology on the in vivo bioactivity, titanium screws coated by Plasma Flame Spraying (PFS) with titanium or fluorinated apatite (K690) were implanted in sheep tibia and femur for 10 weeks and studied by micro-Raman and IR spectroscopy. The same techniques, together with thermogravimetry, were used for characterising the pre-coating K690 powder. Contrary to the manufacturer report, the K690 pre-coating revealed to be composed of a partially fluorinated apatite containing impurities of Ca(OH) 2 and CaCO 3. By effect of PFS, the impurities were decomposed and the crystallinity degree of the coating was found to decrease. The vibrational spectra recorded on the implanted screws revealed the presence of newly formed bone; for the K690-coated screws at least, a high level of osteointegration was evidenced.

  2. Finite Element Analysis of Bone Stress for Miniscrew Implant Proximal to Root Under Occlusal Force and Implant Loading.

    Science.gov (United States)

    Shan, Li-Hua; Guo, Na; Zhou, Guan-jun; Qie, Hui; Li, Chen-Xi; Lu, Lin

    2015-10-01

    Because of the narrow interradicular spaces and varying oral anatomies of individual patients, there is a very high risk of root proximity during the mini implants inserting. The authors hypothesized that normal occlusal loading and implant loading affected the stability of miniscrew implants placed in proximity or contact with the adjacent root. The authors implemented finite element analysis (FEA) to examine the effectiveness of root proximity and root contact. Stress distribution in the bone was assessed at different degrees of root proximity by generating 4 finite element models: the implant touches the root surface, the implant was embedded in the periodontal membrane, the implant touches the periodontal surface, and the implant touches nothing. Finite element analysis was then carried out with simulations of 2 loading conditions for each model: condition A, involving only tooth loading and condition B, involving both tooth and implant loading. Under loading condition A, the maximum stress on the bone for the implant touching the root was the distinctly higher than that for the other models. For loading condition B, peak stress areas for the implant touching the root were the area around the neck of the mini implant and the point of the mini implant touches the root. The results of this study suggest that normal occlusal loading and implant loading contribute to the instability of the mini implant when the mini implant touches the root.

  3. Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck.

    Science.gov (United States)

    Liu, Yang; Wang, Jiawei

    2017-11-01

    To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant. Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts. A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect. Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Breast reconstruction - implants

    Science.gov (United States)

    Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... harder to find a tumor if your breast cancer comes back. Getting breast implants does not take as long as breast reconstruction ...

  5. Cartilage Health in Knees Treated with Metal Resurfacing Implants or Untreated Focal Cartilage Lesions: A Preclinical Study in Sheep.

    Science.gov (United States)

    Martinez-Carranza, Nicolas; Hultenby, Kjell; Lagerstedt, Anne Sofie; Schupbach, Peter; Berg, Hans E

    2017-07-01

    Background Full-depth cartilage lesions do not heal and the long-term clinical outcome is uncertain. In the symptomatic middle-aged (35-60 years) patient, treatment with metal implants has been proposed. However, the cartilage health surrounding these implants has not been thoroughly studied. Our objective was to evaluate the health of cartilage opposing and adjacent to metal resurfacing implants. Methods The medial femoral condyle was operated in 9 sheep bilaterally. A metallic resurfacing metallic implant was immediately inserted into an artificially created 7.5 mm defect while on the contralateral knee the defect was left untreated. Euthanasia was performed at 6 months. Six animals, of similar age and study duration, from a previous study were used for comparison in the evaluation of cartilage health adjacent to the implant. Cartilage damage to joint surfaces within the knee, cartilage repair of the defect, and cartilage adjacent to the implant was evaluated macroscopically and microscopically. Results Six animals available for evaluation of cartilage health within the knee showed a varying degree of cartilage damage with no statistical difference between defects treated with implants or left untreated ( P = 0.51; 95% CI -3.7 to 6.5). The cartilage adjacent to the implant (score 0-14; where 14 indicates no damage) remained healthy in these 6 animals showing promising results (averaged 10.5; range 9-11.5, SD 0.95). Cartilage defects did not heal in any case. Conclusion Treatment of a critical size focal lesion with a metal implant is a viable alternative treatment.

  6. Ion implantation and amorphous metals

    International Nuclear Information System (INIS)

    Hohmuth, K.; Rauschenbach, B.

    1981-01-01

    This review deals with ion implantation of metals in the high concentration range for preparing amorphous layers (>= 10 at%, implantation doses > 10 16 ions/cm 2 ). Different models are described concerning formation of amorphous phases of metals by ion implantation and experimental results are given. The study of amorphous phases has been carried out by the aid of Rutherford backscattering combined with the channeling technique and using transmission electron microscopy. The structure of amorphous metals prepared by ion implantation has been discussed. It was concluded that amorphous metal-metalloid compounds can be described by a dense-random-packing structure with a great portion of metal atoms. Ion implantation has been compared with other techniques for preparing amorphous metals and the adventages have been outlined

  7. A case study of arithmetic facts dyscalculia caused by a hypersensitivity-to-interference in memory.

    Science.gov (United States)

    De Visscher, Alice; Noël, Marie-Pascale

    2013-01-01

    While the heterogeneity of developmental dyscalculia is increasingly recognized, the different profiles have not yet been clearly established. Among the features underpinning types of developmental dyscalculia suggested in the literature, an impairment in arithmetic fact retrieval is particularly prominent. In this paper, we present a case study of an adult woman (DB) with very good cognitive capacities suffering from a specific and developmental arithmetic fact retrieval deficit. We test the main hypotheses about developmental dyscalculia derived from literature. We first explore the influential hypothesis of an approximate number system deficit, through estimation tasks, comparison tasks and a priming comparison task. Secondly, we evaluate whether DB's mathematical deficiencies are caused by a rote verbal memory deficit, using tasks involving completion of expressions, and reciting automatic series such as the alphabet and the months of the year. Alternatively, taking into account the extreme similarity of the arithmetic facts, we propose that a heightened sensitivity to interference could have prevented DB from memorizing the arithmetic facts. The pattern of DB's results on different tasks supports this hypothesis. Our findings identify a new etiology of a specific impairment of arithmetic facts storage, namely a hypersensitivity-to-interference. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Ion implantation into iron

    International Nuclear Information System (INIS)

    Iwaki, Masaya

    1978-01-01

    The distribution of implanted ions in iron, the friction characteristics and the corrosion of iron were studied. The distribution of Ni or Cr ions implanted into mild steel was measured. The accelerated voltage was 150 keV, and the beam current density was about 2 microampere/cm 2 . The measurement was made with an ion microanalyzer. The measured distribution was compared with that of LSS theory. Deep invasion of Ni was seen in the measured distribution. The distribution of Cr ions was different from the distribution calculated by the LSS theory. The relative friction coefficient of mild steel varied according to the dose of implanted Cu or N ions, and to the accelerating voltage. Formation of compound metals on the surfaces of metals by ion-implantation was investigated for the purpose to prevent the corrosion of metals. The resistance of mild steel in which Ni ions were implanted was larger than that of mild steel without any treatment. (Kato, T.)

  9. Implant experience with an implantable hemodynamic monitor for the management of symptomatic heart failure.

    Science.gov (United States)

    Steinhaus, David; Reynolds, Dwight W; Gadler, Fredrik; Kay, G Neal; Hess, Mike F; Bennett, Tom

    2005-08-01

    Management of congestive heart failure is a serious public health problem. The use of implantable hemodynamic monitors (IHMs) may assist in this management by providing continuous ambulatory filling pressure status for optimal volume management. The Chronicle system includes an implanted monitor, a pressure sensor lead with passive fixation, an external pressure reference (EPR), and data retrieval and viewing components. The tip of the lead is placed near the right ventricular outflow tract to minimize risk of sensor tissue encapsulation. Implant technique and lead placement is similar to that of a permanent pacemaker. After the system had been successfully implanted in 148 patients, the type and frequency of implant-related adverse events were similar to a single-chamber pacemaker implant. R-wave amplitude was 15.2 +/- 6.7 mV and the pressure waveform signal was acceptable in all but two patients in whom presence of artifacts required lead repositioning. Implant procedure time was not influenced by experience, remaining constant throughout the study. Based on this evaluation, permanent placement of an IHM in symptomatic heart failure patients is technically feasible. Further investigation is warranted to evaluate the use of the continuous hemodynamic data in management of heart failure patients.

  10. Macro design morphology of endosseous dental implants.

    Science.gov (United States)

    Sahiwal, Indira G; Woody, Ronald D; Benson, Byron W; Guillen, Guillermo E

    2002-05-01

    The identification of dental implant bodies in patients without available records is a considerable problem due to increased patient mobility and to the large number of implant systems with different designs. The purpose of this study was to document the designs of selected implants to help clinicians identify these implants from their radiographic images. More than 50 implant manufacturers were contacted and asked to provide implants with dimensions as close as possible to 3.75 mm (diameter) x 10 mm (length). Forty-four implants were donated, separated into threaded and non-threaded categories, and further sorted into tapered and non-tapered categories. The implants were examined visually, and features on the entire circumference and length of each implant were recorded and categorized as coronal, midbody, or apical. A series of tables describe the 44 implants according to coronal, midbody, and apical features. The results of this project offer dentists basic knowledge of the design of selected dental implants. Such knowledge can aid the radiographic identification of these implants.

  11. Using individual two-posterior short implants with two-anterior standard implants in mandibular implant-supported-overdenture to enhance the patient satisfaction: A clinical report

    Directory of Open Access Journals (Sweden)

    Mehran Bahrami

    2017-01-01

    Full Text Available Introduction: Many clinical cases and the literature review have revealed implant-supported-overdentures’ (ISOs treatment success and predictability in elderly patients. According to the previous studies, all the mandibular ISOs used 2–4 implants anterior to mental foramen to retain the denture. Case Report: In this clinical report, two individual anterior standard implants and two individual posterior short implants were used to support the mandibular ISO, as well as to prevent further posterior bone resorption. This treatment option permits the patient to insert more implants in the future, and could be upgraded to implant-supported-fixed prosthesis. Discussion: The patient was completely satisfied about the final result, especially for upgrading the mastication efficiency. The patient was followed-up for more than 2 years without complication. The panoramic X-ray showed the preserved bone in the posterior region. This technique could be considered to be innovative, and more clinical cases are required to be documented as a predictable modality.

  12. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.

    Science.gov (United States)

    Ersoy, Ahmet Ersan; Turkyilmaz, Ilser; Ozan, Oguz; McGlumphy, Edwin A

    2008-08-01

    Dental implant placement requires precise planning with regard to anatomic limitations and restorative goals. The aim of this study was to evaluate the match between the positions and axes of the planned and placed implants using stereolithographic (SLA) surgical guides. Ninety-four implants were placed using SLA surgical guides generated from computed tomography (CT) between 2005 and 2006. Radiographic templates were used for all subjects during CT imaging. After obtaining three-dimensional CT images, each implant was virtually placed on the CT images. SLA surgical guides, fabricated using an SLA machine with a laser beam to polymerize the liquid photo-polymerized resin, were used during implant placement. A new CT scan was taken for each subject following implant placement. Special software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. Compared to the planned implants, the placed implants showed angular deviation of 4.9 degrees+/-2.36 degrees, whereas the mean linear deviation was 1.22+/-0.85 mm at the implant neck and 1.51+/-1 mm at the implant apex. Compared to the implant planning, the angular deviation and linear deviation at the neck and apex of the placed maxillary implants were 5.31 degrees+/-0.36 degrees, 1.04+/-0.56 mm, and 1.57+/-0.97 mm, respectively, whereas corresponding figures for placed mandibular implants were 4.44 degrees+/-0.31 degrees, 1.42+/-1.05 mm, and 1.44+/-1.03 mm, respectively. SLA surgical guides using CT data may be reliable in implant placement and make flapless implant placement possible.

  13. Protocol for Bone Augmentation with Simultaneous Early Implant Placement: A Retrospective Multicenter Clinical Study

    Directory of Open Access Journals (Sweden)

    Peter Fairbairn

    2015-01-01

    Full Text Available Purpose. To present a novel protocol for alveolar bone regeneration in parallel to early implant placement. Methods. 497 patients in need of extraction and early implant placement with simultaneous bone augmentation were treated in a period of 10 years. In all patients the same specific method was followed and grafting was performed utilizing in situ hardening fully resorbable alloplastic grafting materials consisting of β-tricalcium phosphate and calcium sulfate. The protocol involved atraumatic extraction, implant placement after 4 weeks with simultaneous bone augmentation, and loading of the implant 12 weeks after placement and grafting. Follow-up periods ranged from 6 months to 10 years (mean of 4 years. Results. A total of 601 postextraction sites were rehabilitated in 497 patients utilizing the novel protocol. Three implants failed before loading and three implants failed one year after loading, leaving an overall survival rate of 99.0%. Conclusions. This standardized protocol allows successful long-term functional results regarding alveolar bone regeneration and implant rehabilitation. The concept of placing the implant 4 weeks after extraction, augmenting the bone around the implant utilizing fully resorbable, biomechanically stable, alloplastic materials, and loading the implant at 12 weeks seems to offer advantages when compared with traditional treatment modalities.

  14. Implant decontamination during surgical peri-implantitis treatment : a randomized, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    de Waal, Yvonne C. M.; Raghoebar, Gerry M.; Huddleston Slater, James J. R.; Meijer, Henny J. A.; Winkel, Edwin G.; van Winkelhoff, Arie Jan

    Aim The objective of this randomized, double-blind, placebo-controlled trial was to study the effect of implant surface decontamination with chlorhexidine (CHX)/cetylpyridinium chloride (CPC) on microbiological and clinical parameters. Material & Methods Thirty patients (79 implants) with

  15. Implant decontamination during surgical peri-implantitis treatment : a randomized, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    de Waal, Yvonne C.M.; Raghoebar, Gerry M; Huddleston Slater, James J R; Meijer, Hendrikus; Winkel, Edwin G; van Winkelhoff, Arie Jan

    AIM: The objective of this randomized, double-blind, placebo-controlled trial was to study the effect of implant surface decontamination with chlorhexidine (CHX)/cetylpyridinium chloride (CPC) on microbiological and clinical parameters. MATERIAL & METHODS: Thirty patients (79 implants) with

  16. Different types of implants for reconstructive breast surgery.

    Science.gov (United States)

    Rocco, Nicola; Rispoli, Corrado; Moja, Lorenzo; Amato, Bruno; Iannone, Loredana; Testa, Serena; Spano, Andrea; Catanuto, Giuseppe; Accurso, Antonello; Nava, Maurizio B

    2016-05-16

    reconstructive surgery after prophylactic mastectomy. The studies were heterogenous in terms of implant comparisons, which prevented us from pooling the data.The studies were judged as being at an unclear risk of bias for most risk of bias items owing to poor quality of reporting in the trial publications. Three of the five RCTs were judged to be at high risk of attrition bias, and one at high risk of detection bias.Textured silicone versus smooth silicone implants: textured implants were associated with worse outcomes when compared to smooth implants (capsular contracture: risk ratio (RR) 0.82, 95% CI 0.14 to 4.71; 1 study, 20 participants; very low quality evidence; reintervention: RR 0.82, 95% CI 0.14 to 4.71; 1 study, 20 participants; very low quality evidence). No results in this comparison were statistically significant.Silicone versus saline implants: saline-filled implants performed better than silicone-filled implants for some outcomes; specifically, they produced less severe capsular contracture (RR 3.25, 95% CI 1.24 to 8.51; 1 study, 60 participants; very low quality evidence) and increased patient satisfaction (RR 0.60, 95% CI 0.41 to 0.88; 1 study, 58 participants; very low quality evidence). However reintervention was significantly more frequent in the saline-filled implant group than in the silicone-filled group (OR 0.08, 95% CI 0.01 to 0.43; 1 study, 60 participants; very low quality evidence).Poly(N-vinyl-2-pyrrolidone) hydrogel-filled (PVP-hydrogel) versus saline-filled implants: PVP-hydrogel-filled implants were associated with worse outcomes when compared to saline-filled implants (capsular contracture: RR 3.50, 95% CI 0.83 to 14.83; 1 study, 40 participants; very low quality evidence; short-term complications: RR 2.10, 95% CI 0.21 to 21.39; 1 study, 41 participants; very low quality evidence).Anatomical versus round implants: anatomical implants were associated with worse outcomes than round implants (capsular contracture: RR 2.00, 95% CI 0.20 to 20.15; 1

  17. Stability of dental implants in grafted bone in the anterior maxilla: longitudinal study.

    LENUS (Irish Health Repository)

    Al-Khaldi, Nasser

    2010-06-06

    We aimed to assess the stability over time of dental implants placed in grafted bone in the maxilla using resonance frequency analysis, and to compare the stability of implants placed in grafted and non-grafted bone. Data were collected from 23 patients (15 test and 8 controls) in whom 64 implants (Brånemark system, Nobel Biocare, Göteborg, Sweden) were placed in accordance with the two-stage surgical protocol. In the test group 36 fixtures were placed in grafted bone, and in the control group 28 fixtures were placed in non-grafted bone. Resonance frequency analysis was used to assess the test sites at implant placement and abutment connection. The mean (SD) implant stability quotient (ISQ) for test sites at the time of implant placement was 61.91 (6.68), indicating excellent primary stability, and was 63.53 (5.76) at abutment connection. ISQ values at abutment connection were similar for test and control sites. Implants placed in grafted bone compared favourably with those in non-grafted bone, and showed excellent stability.

  18. Study of TiO2 nanotubes as an implant application

    International Nuclear Information System (INIS)

    Hazan, Roshasnorlyza; Sreekantan, Srimala; Mydin, Rabiatul Basria S. M. N.; Mat, Ishak; Abdullah, Yusof

    2016-01-01

    Vertically aligned TiO 2 nanotubes have become the primary candidates for implant materials that can provide direct control of cell behaviors. In this work, 65 nm inner diameters of TiO 2 nanotubes were successfully prepared by anodization method. The interaction of bone marrow stromal cells (BMSC) in term of cell adhesion and cell morphology on bare titanium and TiO 2 nanotubes is reported. Field emission scanning electron microscopy (FESEM) analysis proved interaction of BMSC on TiO 2 nanotubes structure was better than flat titanium (Ti) surface. Also, significant cell adhesion on TiO 2 nanotubes surface during in vitro study revealed that BMSC prone to attach on TiO 2 nanotubes. From the result, it can be conclude that TiO 2 nanotubes are biocompatible to biological environment and become a new generation for advanced implant materials

  19. Pilot study on the use of data mining to identify cochlear implant candidates.

    Science.gov (United States)

    Grisel, Jedidiah J; Schafer, Erin; Lam, Anne; Griffin, Terry

    2018-05-01

    The goal of this pilot study was to determine the clinical utility of data-mining software that screens for cochlear implant (CI) candidacy. The Auditory Implant Initiative developed a software module that screens for CI candidates via integration with a software system (Noah 4) that serves as a depository for hearing test data. To identify candidates, patient audiograms from one practice were exported into the screening module. Candidates were tracked to determine if any eventually underwent implantation. After loading 4836 audiograms from the Noah 4 system, the screening module identified 558 potential CI candidates. After reviewing the data for the potential candidates, 117 were targeted and invited to an educational event. Following the event, a total of six candidates were evaluated, and two were implanted. This objective approach to identifying candidates has the potential to address the gross underutilization of CIs by removing any bias or lack of knowledge regarding the management of severe to profound sensorineural hearing loss with CIs. The screening module was an effective tool for identifying potential CI candidates at one ENT practice. On a larger scale, the screening module has the potential to impact thousands of CI candidates worldwide.

  20. Alzheimer's Disease Facts and Figures

    Medline Plus

    Full Text Available ... Share the facts: Quick Facts Prevalence Mortality Caregivers Cost Special Report Alzheimer's in each state Quick Facts Share the facts: Prevalence The number of Americans living with Alzheimer's is growing — and growing fast. An ...