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Sample records for implant study fact

  1. Fatigue of Dental Implants: Facts and Fallacies

    OpenAIRE

    Keren Shemtov-Yona; Daniel Rittel

    2016-01-01

    Dental implants experience rare yet problematic mechanical failures such as fracture that are caused, most often, by (time-dependent) metal fatigue. This paper surveys basic evidence about fatigue failure, its identification and the implant’s fatigue performance during service. We first discuss the concept of dental implant fatigue, starting with a review of basic concepts related to this failure mechanism. The identification of fatigue failures using scanning electron microscopy follows, to ...

  2. Fatigue of Dental Implants: Facts and Fallacies

    Directory of Open Access Journals (Sweden)

    Keren Shemtov-Yona

    2016-05-01

    Full Text Available Dental implants experience rare yet problematic mechanical failures such as fracture that are caused, most often, by (time-dependent metal fatigue. This paper surveys basic evidence about fatigue failure, its identification and the implant’s fatigue performance during service. We first discuss the concept of dental implant fatigue, starting with a review of basic concepts related to this failure mechanism. The identification of fatigue failures using scanning electron microscopy follows, to show that this stage is fairly well defined. We reiterate that fatigue failure is related to the implant design and its surface condition, together with the widely varying service conditions. The latter are shown to vary to an extent that precludes devising average or representative conditions. The statistical nature of the fatigue test results is emphasized throughout the survey to illustrate the complexity in evaluating the fatigue behavior of dental implants from a design perspective. Today’s fatigue testing of dental implants is limited to ISO 14801 standard requirements, which ensures certification but does not provide any insight for design purposes due to its limited requirements. We introduce and discuss the random spectrum loading procedure as an alternative to evaluate the implant’s performance under more realistic conditions. The concept is illustrated by random fatigue testing in 0.9% saline solution.

  3. Disability Studies. NRC Fact Sheet

    Science.gov (United States)

    Harris, Perri

    2010-01-01

    Over the past several decades, what people now refer to as "disability studies" has been a powerful influence on policy and practice in regards to people with disabilities. Disability studies has evolved as a means of addressing how people with disabilities have been treated historically and how they continue to be treated. The field of disability…

  4. Basic Facts on Study Abroad.

    Science.gov (United States)

    Council on International Educational Exchange, New York, NY.

    This guide for students interested in studying abroad gives an overview of the factors to be considered and the choices to be made and provides references to sources of further information. The following topics are addressed: (1) planning (academic objectives, location, the third world, language proficiency, special laws, the disabled); (2)…

  5. Study of Endometrial Receptivity during Implantation in Implantation Dysfunction Mouse

    Institute of Scientific and Technical Information of China (English)

    Yan-juan LIU; Guang-ying HUANG; Ming-wei YANG; Fu-er LU

    2008-01-01

    Objective To establish the mice model of implantation dysfunction and to study the endometrial receptivity during implantation in implantation dysfunction mouse. Methods Sexually mature female virgin, Kunming mice were randomly assigned to the control group and the model group postcoitally. The model mice at 9 : 00 AM on d 4 of pregnancy(d 4) were injected subcutaneously with mifepristone. All animals were sacrificed at 9:00 PM on d 4 and their uterine horns were examined for the presence of implanted embryos. Histopathology of uterine endometrium was observed by light-microscope. The endometrial expressions of estrogen receptor (ER) and progesterone receptor (PR) assessed by immunnohistochemical SP method. The endometrial expressions of ER mRNA and PR mRNA were assessed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR).Results Compared with control group, implantation rates and average embryo number significently decreased in model group, the development of endometrium was inhibited. In model group, absorbency and area rate of ER and PR in the gland and stroma were lower than those in control group (P<0.05). Expressions of ER mRNA and PR mRNA in model uterus were significantly lower than those in the control.Conclusion The endometrial receptivity and implantation decreased in mifepristoneinduced implantation dysfunction mouse.

  6. CO2 laser surface treatment of failed dental implants for re-implantation: an animal study.

    Science.gov (United States)

    Kasraei, Shahin; Torkzaban, Parviz; Shams, Bahar; Hosseinipanah, Seyed Mohammad; Farhadian, Maryam

    2016-07-01

    The aim of the present study was to evaluate the success rate of failed implants re-implanted after surface treatment with CO2 laser. Despite the widespread use of dental implants, there are many incidents of failures. It is believed that lasers can be applied to decontaminate the implant surface without damaging the implant. Ten dental implants that had failed for various reasons other than fracture or surface abrasion were subjected to CO2 laser surface treatment and randomly placed in the maxillae of dogs. Three failed implants were also placed as the negative controls after irrigation with saline solution without laser surface treatment. The stability of the implants was evaluated by the use of the Periotest values (PTVs) on the first day after surgery and at 1, 3, and 6 months post-operatively. The mean PTVs of treated implants increased at the first month interval, indicating a decrease in implant stability due to inflammation followed by healing of the tissue. At 3 and 6 months, the mean PTVs decreased compared to the 1-month interval (P implant stability. The mean PTVs increased in the negative control group compared to baseline (P implants were significantly lower than control group at 3 and 6 months after implant placement (P implantation of failed implants in Jack Russell Terrier dogs after CO2 laser surface debridement is associated with a high success rate in terms of implant stability.

  7. 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...

  8. "Peri-Implantitis": A Complication of a Foreign Body or a Man-Made "Disease". Facts and Fiction.

    Science.gov (United States)

    Albrektsson, Tomas; Canullo, Luigi; Cochran, David; De Bruyn, Hugo

    2016-08-01

    The discrepancy between some scientific views and the daily clinical experience with dental implants has made the topic of "periimplantitis" highly controversial, especially the discussion whether "periimplantitis" should even be considered a "disease" or whether marginal bone loss instead would represent a complication of having a foreign body placed in the oral cavity. The aim of the present paper was to present the outcomes from a consensus meeting on "peri-implantitis" in Rome, Italy (January 8-10, 2016). Seventeen clinical scientists were invited to, based on prepared reviews of the literature, discuss topics related to "periimplantitis." Oral implants may lose bone or even display clinical failure. However, progressive bone loss threatening implant survival is rare and limited to a percent or two of all implants followed up over 10 years or more, provided that controlled implant systems are being used by properly trained clinicians. There is very little evidence pointing to implants suffering from a defined disease entity entitled "peri-implantitis." Marginal bone loss around implants is in the great majority of cases associated with immune-osteolytic reactions. Complicating factors include patient genetic disorders, patient smoking, cement or impression material remnants in the peri-implant sulcus, bacterial contamination of the implant components and technical issues such as loose screws, mobile components or fractured materials. These reactions combine to result in cellular responses with the end result being a shift in the delicate balance between the osteoblast and the osteoclast resulting in bone resorption. However, the great majority of controlled implants display a foreign body equilibrium resulting in very high survival rates of the implants over long term of follow-up. © 2016 Wiley Periodicals, Inc.

  9. Influence of bone density on implant stability parameters and implant success: a retrospective clinical study

    Directory of Open Access Journals (Sweden)

    McGlumphy Edwin A

    2008-11-01

    Full Text Available Abstract Background The aim of the present clinical study was to determine the local bone density in dental implant recipient sites using computerized tomography (CT and to investigate the influence of local bone density on implant stability parameters and implant success. Methods A total of 300 implants were placed in 111 patients between 2003 and 2005. The bone density in each implant recipient site was determined using CT. Insertion torque and resonance frequency analysis were used as implant stability parameters. The peak insertion torque values were recorded with OsseoCare machine. The resonance frequency analysis measurements were performed with Osstell instrument immediately after implant placement, 6, and 12 months later. Results Of 300 implants placed, 20 were lost, meaning a survival rate of %. 93.3 after three years (average 3.7 ± 0.7 years. The mean bone density, insertion torque and RFA recordings of all 300 implants were 620 ± 251 HU, 36.1 ± 8 Ncm, and 65.7 ± 9 ISQ at implant placement respectively; which indicated statistically significant correlations between bone density and insertion torque values (p Conclusion CT is a useful tool to determine the bone density in the implant recipient sites, and the local bone density has a prevailing influence on primary implant stability, which is an important determinant for implant success.

  10. Impact of crestal and subcrestal implant placement in peri-implant bone: A prospective comparative study.

    Science.gov (United States)

    Pellicer-Chover, Hilario; Peñarrocha-Diago, María; Peñarrocha-Oltra, David; Gomar-Vercher, Sonia; Agustín-Panadero, Rubén; Peñarrocha-Diago, Miguel

    2016-01-01

    To assess the influence of the crestal or subcrestal placement of implants upon peri-implant bone loss over 12 months of follow-up. Twenty-six patients with a single hopeless tooth were recruited in the Oral Surgery Unit (Valencia University, Valencia, Spain). The patients were randomized into two treatment groups: group A (implants placed at crestal level) or group B (implants placed at subcrestal level). Control visits were conducted by a trained clinician at the time of implant placement and 12 months after loading. A previously established standard protocol was used to compile general data on all patients (sex and age, implant length and diameter, and brushing frequency). Implant success rate, peri-implant bone loss and the treatment of the exposed implant surface were studied. The level of statistical significance was defined as 5% (α=0.05). Twenty-three patients (8 males and 15 females, mean age 49.8±11.6 years, range 28-75 years) were included in the final data analyses, while three were excluded. All the included subjects were non-smokers with a brushing frequency of up to twice a day in 85.7% of the cases. The 23 implants comprised 10 crestal implants and 13 subcrestal implants. After implant placement, the mean bone position with respect to the implant platform in group A was 0.0 mm versus 2.16±0.88 mm in group B. After 12 months of follow-up, the mean bone positions were -0.06±1.11 mm and 0.95±1.50 mm, respectively - this representing a bone loss of 0.06±1.11 mm in the case of the crestal implants and of 1.22±1.06 mm in the case of the subcrestal implants (p=0.014). Four crestal implants and 5 subcrestal implants presented peri-implant bone levels below the platform, leaving a mean exposed treated surface of 1.13 mm and 0.57 mm, respectively. The implant osseointegration success rate at 12 months was 100% in both groups. Within the limitations of this study, bone loss was found to be greater in the case of the subcrestal implants, though from the

  11. [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.

  12. Making the most of human memory : Studies on personalized fact-learning and visual working memory

    NARCIS (Netherlands)

    Sense, Florian

    2017-01-01

    Rote learning of facts is boring. Here, we present a way to make it more efficient so facts are learned faster. Learners usually need to repeat facts multiple times to learn them well. The optimal timing of these repetitions depends on the facts that are studied and the characteristics of the

  13. Comparative study on the osseointegration of implants in dog mandibles according to the implant surface treatment

    Science.gov (United States)

    2016-01-01

    Objectives This study compared the impact of implant surface treatment on the stability and osseointegration of implants in dog mandibles. Materials and Methods Six adult dogs received a total of 48 implants that were prepared using four different surface treatments; resorbable blast media (RBM), hydroxyapatite (HA), hydrothermal-treated HA, and sand blasting and acid etching (SLA). Implants were installed, and dogs were separated into 2- and 4-week groups. Implant stability was evaluated via Periotest M, Osstell Mentor, and removal torque analyzers. A histomorphometric analysis was also performed. Results The stability evaluation showed that all groups generally had satisfactory values. The histomorphometric evaluation via a light microscope revealed that the HA surface implant group had the highest ratio of new bone formation on the entire fixture. The hydrothermal-treated HA surface implant group showed a high ratio of bone-to-implant contact in the upper half of the implant area. Conclusion The hydrothermal-treated HA implant improved the bone-to-implant contact ratio on the upper fixture, which increased the implant stability. PMID:28053904

  14. Axial relationship between dental implants and teeth/implants: a radiographic study.

    Science.gov (United States)

    Machtei, Eli E; Oettinger-Barak, Orit; Horwitz, Jacob

    2014-08-01

    The relationship of dental implants with neighboring teeth will affect both occlusal relationship and distribution of forces; thus, the purpose of this study was to examine implants' axial relationship with adjacent and opposing teeth/implants. Data of dental implants patients was retrieved. Panoramic X rays were digitized. Computer-based software was used to measure the angular relationship between the implants and adjacent/opposing teeth and implants. Data was further sorted by the mode of placement and implants position. 50 patients (219 implants) were included. Mean angle to adjacent tooth/implant was 178.71° ± 9.18° (range 129.7°-206°). Implants were more parallel to adjacent teeth (180.99° ± 1.06°) than to adjacent implants (176.32° ± 0.54°; P = .0001). Mean angular relationship to opposite tooth was 167.88° ± 8.92° (range 137.7°-179.8°). Implants that were placed freehand or with positional guide had similar intra-arch relationship (178.22° and 178.81°, respectively) and similar inter-arch angulations (164.46° and 167.74°). Molars had greater deviation of the angular relationship (175.54°) compared to premolars (181.62°) and incisors (180.55°, P = .0001). Implants placed in the maxilla had smaller axial deviation compared to implants in the mandible (180.41° ± 0.64 vs 177.14° ± 1.02; P = .0081). Good axial relationship may be obtained in most implants placed by an experienced clinician, even when placed freehand. The mandibular posterior region is more prone to axial deviation and as such requires special attention.

  15. A Longitudinal Study in Children with Sequential Bilateral Cochlear Implants: Time Course for the Second Implanted Ear and Bilateral Performance

    Science.gov (United States)

    Reeder, Ruth M.; Firszt, Jill B.; Cadieux, Jamie H.; Strube, Michael J.

    2017-01-01

    Purpose: Whether, and if so when, a second-ear cochlear implant should be provided to older, unilaterally implanted children is an ongoing clinical question. This study evaluated rate of speech recognition progress for the second implanted ear and with bilateral cochlear implants in older sequentially implanted children and evaluated localization…

  16. A Longitudinal Study in Children with Sequential Bilateral Cochlear Implants: Time Course for the Second Implanted Ear and Bilateral Performance

    Science.gov (United States)

    Reeder, Ruth M.; Firszt, Jill B.; Cadieux, Jamie H.; Strube, Michael J.

    2017-01-01

    Purpose: Whether, and if so when, a second-ear cochlear implant should be provided to older, unilaterally implanted children is an ongoing clinical question. This study evaluated rate of speech recognition progress for the second implanted ear and with bilateral cochlear implants in older sequentially implanted children and evaluated localization…

  17. Dental implants in persons with severe epilepsy and multiple disabilities: a long-term retrospective study.

    Science.gov (United States)

    Cune, Marco S; Strooker, Hans; van der Reijden, Willy A; de Putter, Cornelis; Laine, Maria L; Verhoeven, Jan Willem

    2009-01-01

    A retrospective study on the performance of endosseous implants in a population of patients with severe epilepsy and additional motor and/or intellectual impairments was performed. All residents of an inpatient center for persons affected by severe, refractory epilepsy and multiple disabilities who received endosseous implants between 1991 and April 2007 were included in the study. Implant survival was analyzed using the Kaplan-Meier method. A subset of patients who were treated between 1991 and 2004 was invited to participate in a clinical and radio?graphic evaluation in 2004 and 2005. A total of 61 patients were treated between 1991 and April 2007 (n=134 implants). Three of these implants in three different patients failed during the observation period, demonstrating an estimated probability of functional implant survival of 97.6% (SE 1.4%) after 16 years. In patients who were seen during the clinical evaluation in 2004 (n=76 implants), only mild inflammation of the peri-implant mucosa was generally observed (Gingival-Bleeding Index=1), despite the fact that the level of oral hygiene was considered inadequate around 55 of 76 implants (72%). Obvious signs of drug-induced gingival hyperplasia in relation to the implants were not observed. Probing depths averaged approximately 2 mm. Stable marginal bone levels were observed on the radiographs. Dental implant treatment in a population of patients with severe epilepsy and additional disabilities seems to be a viable treatment option. Implant loss is rare. Although adequate plaque control was not feasible in all patients, marginal bone levels remained stable.

  18. The risk of bleeding of triple therapy with vitamin K-antagonists, aspirin and clopidogrel after coronary stent implantation: Facts and questions

    Institute of Scientific and Technical Information of China (English)

    Andrea Rubboli

    2011-01-01

    Background Triple therapy (TT) with vitamin K-antagonists (VKA),aspirin and clopidogrel is the recommended antithrombotic treatment following percutaneous coronary intervention with stent implantation (PCI-S) in patients with an indication for oral anticoagulation.TT is associated with an increased risk of bleeding,but available evidence is flawed by important limitations,including the limited size and the retrospective design of most of the studies,as well as the rare reporting of the incidence of in-hospital bleeding and the treatment which was actually ongoing at the time of bleeding.Since the perceived high bleeding risk of TT may deny patients effective strategies,the determination of the true safety profile of TT is of paramount importance.Methods All the 27 published studies where the incidence of bleeding at various time points during follow-up has been reported separately for patients on TT were reviewed,and the weakness of the data was analyzed.Results The absolute incidence of major bleeding upon discharge at in-hospital,< 1 month,6 months,12 months and ≥ 12months was: 3.3% ± 1.9%,5.1% ± 6.7%,8.0% ± 5.2%,9.0% ± 8.0,and 6.2% ± 7.8%,respectively,and not substantially different from that observed in previous studies with prolonged dual antiplatelet treatment with aspirin and clopidogrel.Conclusions While waiting for the ongoing,large-scale,registries and clinical trials to clarify the few facts and to answer the many questions regarding the risk of bleeding of TT,this treatment should not be denied to patients with an indication for VKA undergoing PCI-S provided that the proper measures and cautions are implemented.

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

    OpenAIRE

    Stamatović Novak; Matić Smiljana; Tatić Zoran; Petković-Ćurčin Aleksandra; Vojvodić Danilo; Rakić Mia

    2013-01-01

    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 t...

  20. Correlative Microscopy of Bone in Implant Osteointegration Studies

    Directory of Open Access Journals (Sweden)

    Alessandra Triré

    2010-01-01

    Full Text Available Routine morphological analyses usually include investigations by light microscopy (LM, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. Each of these techniques provides specific information on tissue morphology and all the obtained results are then combined to give an in-depth morphological overview of the examined sample. The limitations of this traditional comparative microscopy lie in the fact that each technique requires a different experimental sample, so that many specimens are necessary and the combined results come from different samples. The present study describes a technical procedure of correlative microscopy, which allows us to examine the same bone section first by LM and then, after appropriate processing, by SEM or TEM. Thanks to the possibility of analyzing the same undecalcified bone sections both by LM and SEM, the approach described in the present study allows us to make very accurate evaluations of old/new bone morphology at the bone-implant interface.

  1. Evaluation of surgically retrieved temporomandibular joint alloplastic implants: pilot study.

    Science.gov (United States)

    Ferreira, Joao N A R; Ko, Ching-Chang; Myers, Sandra; Swift, James; Fricton, James R

    2008-06-01

    The purpose of this study was to perform a retrieval analysis of temporomandibular joint (TMJ) alloplastic interpositional implants and test possible correlation between implant failure features and patient clinical outcomes. In addition, we investigated the implants' surface and examined the foreign body reaction associated with different types of alloplastic materials. Twelve implants (Proplast/Teflon [Vitek, Houston, TX] and Silastic [Dow Corning, Midland, MI]) were surgically removed from the patients' TMJs. Implant surface failure features (fracture length, perforation of the implants) were observed using stereomicroscopy and recorded for description of the failure mechanisms and to statistically compare with clinical outcomes. Patients' clinical data (pain symptoms and mandibular function) were collected and examined. Clinical outcomes were obtained relative to symptom severity (Symptom Severity Index [SSI]) and jaw function (modified Mandibular Function Impairment Questionnaire [mMFIQ]). Peri-implant soft tissues and implants were analyzed with light microscopy and stereo zoom microscopy. Electron microprobe analysis of implant fragments and peri-implant tissues was performed. The statistical results showed that only the presence of implant perforation was statistically associated with the SSI, specifically with the pain tolerability dimension. No statistical association was seen between any of the other implant failure predictors and the SSI and between the predictors and the mMFIQ. Stereo zoom microscopy suggested that Proplast/Teflon implants (n = 7) were susceptible to perforation, layer tearing, fracture and fiber extrusion. The Silastic implants (n = 3) revealed a possible center perforation with fracture lines towards the periphery and fiber extrusion. Teflon implant wear debris particles appear to trigger a multinucleated giant cell foreign body reaction. Facial pain was a significant correlate to perforation and breakdown of the alloplastic TMJ

  2. 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.

  3. Temperature-dependant study of phosphorus ion implantation in germanium

    Science.gov (United States)

    Razali, M. A.; Smith, A. J.; Jeynes, C.; Gwilliam, R. M.

    2012-11-01

    We present experimental results on shallow junction formation in germanium by phosphorus ion implantation and standard rapid thermal processing. An attempt is made to improve phosphorus activation by implanting phosphorus at high and low temperature. The focus is on studying the germanium damage and phosphorus activation as a function of implant temperature. Rutherford backscattering spectrometry with channelling and Hall Effect measurements are employed for characterisation of germanium damage and phosphorus activation, respectively. High and low temperature implants were found to be better compared to room temperature implant.

  4. 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

    AIM: The aim of the present experiment was to study peri-implant tissue reactions to lateral static load at implants subjected to experimental mucositis or peri-implantitis. MATERIAL AND METHODS: 5 beagle dogs were used. The mandibular premolars were extracted. After 12 weeks, 3 implants were ins...

  5. Exfoliative cytology and titanium dental implants: a pilot study.

    Science.gov (United States)

    Olmedo, Daniel G; Nalli, Gabriela; Verdú, Sergio; Paparella, María L; Cabrini, Rómulo L

    2013-01-01

    Oral exfoliative cytology is a diagnostic method that involves the study of cells exfoliated from the oral mucosa. Ions/particles released from metallic implants can remain in the peri-implant milieu. The aim of the present study is to assess the presence of metal particles in cells exfoliated from peri-implant oral mucosa around titanium dental implants. The study comprised 30 patients carrying titanium dental implants, who had neither a metallic prosthesis nor metal restorations in neighboring teeth. Individuals undergoing orthodontic therapy and those who had oral piercing were also excluded from the study. The study sample included patients with and without peri-implantitis. Cytologic samples of the peri-implant area were collected. Samples of the marginal gingiva on the contralateral side of the implant were taken from the same individuals to serve as control. Cytologic analysis was performed using light microscopy. Titanium concentration was determined using inductively coupled plasma-mass spectrophotometry. Metal-like particles were observed inside and outside epithelial cells and macrophages in cytologic smears of peri-implant mucosa of both patients with and without peri-implantitis. No particles were found in the control cytologic samples. The concentration of titanium was higher in the peri-implantitis group compared with the group without peri-implantitis; no traces of titanium were observed in controls. Regardless of an inflammatory response, ions/particles are released from the surface of the implant into the biologic milieu. Exfoliative cytology is a simple technique that may be used to detect metal particles in cells exfoliated from the peri-implant mucosa.

  6. 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.

  7. PLEPS study of ions implanted RAFM steels

    Science.gov (United States)

    Sojak, S.; Slugeň, V.; Egger, W.; Ravelli, L.; Petriska, M.; Veterníková, J.; Stacho, M.; Sabelová, V.

    2014-04-01

    Current nuclear power plants (NPP) require radiation, heat and mechanical resistance of their structural materials with the ability to stay operational during NPP planned lifetime. Radiation damage much higher, than in the current NPP, is expected in new generations of nuclear power plants, such as Generation IV and fusion reactors. Investigation of perspective structural materials for new generations of nuclear power plants is among others focused on study of reduced activation ferritic/martensitic (RAFM) steels. These steels have good characteristics as reduced activation, good resistance to volume swelling, good radiation, and heat resistance. Our experiments were focused on the study of microstructural changes of binary Fe-Cr alloys with different chromium content after irradiation, experimentally simulated by ion implantations. Fe-Cr alloys were examined, by Pulsed Low Energy Positron System (PLEPS) at FRM II reactor in Garching (Munich), after helium ion implantations at the dose of 0.1 C/cm2. The investigation was focused on the chromium effect and the radiation defects resistivity. In particular, the vacancy type defects (monovacancies, vacancy clusters) have been studied. Based on our previous results achieved by conventional lifetime technique, the decrease of the defects size with increasing content of chromium is expected also for PLEPS measurements.

  8. Spiral Tomography for Determining Implant Angulation: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Z. Dalili Kajan

    2008-06-01

    Full Text Available Objective: To study the accuracy of spiral tomography in the determination of implant angulation.Materials and Methods: Eighteen gutta-percha filled points on dry mandibles were se-lected for implant placement. A translucent acrylic template was fabricated for each man-dible. After preparing tomographic images (2 mmslice thickness, Cranex Tome, the ideal axis of the implant was traced. The angle between the ideal axis and the tangent line on the alveolar crest in the buccal side was measured and transferred to aluminum sleeves by a protractor. After implant placement, tomographic images were taken again and angles of the actual implants were estimated. In addition, thedistances from the tip of the actual and the supposed implants to the buccal cortex were measured. The data were analyzed by paired sample t test with 95% confidence.Results: Less than two-degreedifference between angles of the supposed and the actual implants was found in 44.4% of the cases, whilst 33.3% revealed more than five-degreedifference. There was a significant statistical difference between the angle of the actual and the supposed implants. There was also a significant statistical difference between the linear distances from the tip of the actual and the supposed implants to buccal cortex(P=0.015Conclusion: Spiral tomography in combination with template may provide acceptable re-sults concerning implant angulation and prediction of cortical perforation risk.

  9. Smoke Sense Study Supported by Citizen Scientists Fact Sheet

    Science.gov (United States)

    EPA researchers are conducting a citizen science study called Smoke Sense to determine the extent to which exposure to wildland fire smoke affects health and productivity, and develop health risk communication strategies that protect public health.

  10. 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)

  11. Drug Facts

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  12. Photoluminescence study on Eu-implanted GaN

    Institute of Scientific and Technical Information of China (English)

    Zhang Chun-Guang; Bian Liu-Fang; Chen Wei-De

    2005-01-01

    The photoluminescence (PL) properties of Eu-implanted GaN thin films are studied. The experimental results show that the PL intensity is seriously affected by ion implantation conditions. The PL efficiency increases exponentially with annealing temperature increasing up to a maximum temperature of 1050℃. Moreover, the PL intensity for the sample implanted along the channelling direction is nearly twice more than that observed from the sample implanted along the random direction. The thermal quenching of PL intensity from 10K to 300K for sample annealed at 1050℃ is only 42.%.

  13. 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

  14. 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

  15. Study Pinpoints Sources of Polluting Vehicle Emissions (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-01

    Unburned lubricant produces 60%-90% of organic carbon emissions. While diesel fuel is often viewed as the most polluting of conventional petroleum-based fuels, emissions from gasoline engines can more significantly degrade air quality. Gasoline exhaust is at least as toxic on a per-unit-mass basis as diesel exhaust, and contributes up to 10 times more particulate matter (PM) to the emission inventory. Because emissions from both fuels can gravely impact health and the environment, researchers at the National Renewable Energy Laboratory (NREL) launched a study to understand how these pollutants relate to fuels, lubricants, and engine operating conditions. NREL's Collaborative Lubricating Oil Study on Emissions (CLOSE) project tested a variety of vehicles over different drive cycles at moderate (72 F) and cold (20 F) temperatures. Testing included: (1) Normal and high-emitting light-, medium-, and heavy-duty vehicles; (2) Gasoline, diesel, and compressed natural gas (CNG)-powered vehicles; (3) New and aged lubricants representative of those currently on the market; and (4) Gasoline containing no ethanol, E10, Texas-mandated low-emission diesel fuel, biodiesel, and CNG. The study confirmed that normally functioning emission control systems for gasoline light-duty vehicles are very effective at controlling organic carbon (OC) emissions. Diesel vehicles without aftertreatment emission control systems exhibited OC emissions approximately one order of magnitude higher than gasoline vehicles. High-emitter gasoline vehicles produced OC emissions similar to diesel vehicles without exhaust aftertreatment emission control. Exhaust catalysts combusted or converted more than 75% of lubricating oil components in the exhaust gases. Unburned crankcase lubricant made up 60%-90% of OC emissions. This OC represented 20%-50% of emitted PM in all but two of the vehicles. Three-way catalysts proved effective at reducing most of the OC. With high PM emitters or vehicles with

  16. Myths and facts about vitiligo: An epidemiological study

    Directory of Open Access Journals (Sweden)

    Suja Abraham

    2015-01-01

    Full Text Available Vitiligo is a pigmentary disorder associated with many disease conditions that necessitates multiple drug regimens, which make the treatment complicated. This stigmatic disease forces the patient to approach all system of medicines as well as alternative medicines of non proven value, which further worsens the situation. At the same time the nonadherence to the treatment reflects poor prognosis, which is misunderstood for lack of response resulting in poor faith to the medications. The aim of this work was to assess the patient compliance and the factors affecting, and to monitor the adverse effects as well as drug interactions. The study was carried out in the Institute of Applied Dermatology for a period of one year. Patient compliance was assessed using Morisky Medication Adherence Scale and found that 71% of the patients were low adherent to medications. Family support, faith in doctor, higher educational status and effectiveness of the treatment were some of the reasons for medication adherence whereas forgetfulness, feasibility, occupational problem, polypharmacy, longer duration of treatment and the feeling that the disease under is control were some of the reasons listed for nonadherence. Three adverse reactions were reported with narrow band ultraviolet B and topical tacrolimus therapy and they were categorized into possible and probable according to causality assessment by Naranjo scale. Five drug interactions were reported and the causality assessment was done using drug interaction probability scale. None of the reactions were serious or life threatening. The present study revealed the hurdles in providing safe and effective treatment to the patients and also it suggest the need of doing more research on this disease since there is a general belief that vitiligo is an incurable disease.

  17. Prognosis of single molar implants: a retrospective study.

    Science.gov (United States)

    Kim, Young-Kyun; Kim, Su-Gwan; Yun, Pil-Young; Hwang, Jung-Won; Son, Mee-Kyoung

    2010-08-01

    The purpose of this study was to evaluate the short- and mid-term prognosis of maxillary and mandibular single molar implants, prosthetic complications, and factors mediating the effects seen on them. Eighty-seven patients were enrolled consecutively in this study and 96 implants were placed into a single molar defect site by one oral and maxillofacial surgeon from March 2004 to December 2006. Primary osseointegration failure developed in two implants and delayed implant failure occurred at four implants. The fraction surviving interval was 97% to 100%, and at the last follow-up observation, the cumulative survival rate was 91.1%. All failed implants occurred in second molar sites, and the failure rate, according to implant site, showed a significant difference. Prosthetic complications, such as screw loosening, showed a significant correlation to the mesiodistal cantilever. Furthermore, crestal bone loss 3 years after loading was 0.2 mm on average and a very stable result was obtained. Based on the results, the risk of failure for maxillary and mandibular single molar implants is high and the possibility of developing prosthetic complications during loading is also high. Therefore, to minimize the cantilever, implants must be placed precisely and followed carefully and maintained for a long period of time.

  18. 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 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 dental implants can be immediately used successfully for retaining lower complete dentures, as shown after a 1-year follow up. © 2016 Wiley Periodicals, Inc.

  19. A preliminary study looking at parental emotions following cochlear implantation.

    Science.gov (United States)

    Anagnostou, Flora; Graham, John; Crocker, Susan

    2007-06-01

    This preliminary research investigated the emotions of parents with cochlear implanted children. The object for the research was first to compare four emotions engendered in parents of deaf children before and after cochlear implantation. Second, to monitor changes in these emotions during a period of up to four years after implantation. Third, to see whether any of the emotions studied was significantly more prominent than the others, and fifth to identify any differences in emotions that were related to the gender of parents. A self-report questionnaire was given to 112 participants of whom 53 replied. There were equal groups of parents in two categories, those with children up to two years after implantation, and those two to four years after implantation. The responses were interpreted using parametric statistics. The results highlight that grief is the strongest emotional condition that parents experience before and up to two years after implantation, alongside family adjustments. Parents of the up to two years after implantation group generally have stronger feelings and are less satisfied than parents in the over two years implanted group. Finally, fathers use denial more than mothers. Considerations for future research and implications for paediatric cochlear implant teams will be discussed.

  20. Spectroscopic studies of ion implanted PPV films

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, C. (Cavendish Lab., Univ. of Cambridge (United Kingdom)); Friend, R.H. (Cavendish Lab., Univ. of Cambridge (United Kingdom)); Sarnecki, G.J. (Cavendish Lab., Univ. of Cambridge (United Kingdom)); Lucas, B. (LEPOFI, Faculte des Sciences, 87 - Limoges (France)); Moliton, A. (LEPOFI, Faculte des Sciences, 87 - Limoges (France)); Ratier, B. (LEPOFI, Faculte des Sciences, 87 - Limoges (France)); Belorgeot, C. (Lab. de Physique Moleculaire, Faculte des Sciences, 87 - Limoges (France))

    1993-03-15

    The main results of the spectroscopic analyses (infrared and ultraviolet - visible - near infrared) carried out on PPV films before and after ion implantation with halogen and alkali ions are presented in this paper. The influence of both ions nature and implantation parameters on optical properties of this polymer have been pointed out and the appearance of a weak band due to doping has been observed by infrared spectroscopy. (orig.)

  1. Dental Implants - Perceiving Patients' Satisfaction in Relation to Clinical and Electromyography Study on Implant Patients.

    Directory of Open Access Journals (Sweden)

    Mohammad Khursheed Alam

    Full Text Available The aim of this study is to evaluate the satisfaction of patients with posterior implants in relation to the clinical success criteria and surface electromyography (sEMG findings of the masseter and temporalis muscles. Total 42 subjects were investigated. Twenty one subjects with posterior dental implants were interviewed using a questionnaire and the clinical success criteria were determined based on The International Congress of Oral Implantologists. The myofunction of the masticatory muscles were assessed using sEMG (21 subjects and compared to the control group of subjects without implants (21 subjects. Out of 21 subjects, all were satisfied with the aesthetics of their implant. Twenty of them (95.2% were satisfied with its function and stability. As for clinical criteria, 100% (50 of the implants were successful with no pain, mobility or exudates. sEMG findings showed that patients have significantly lower (p<0.01 basal or resting median power frequency but with muscle burst. During chewing, control subjects showed faster chewing action. There was no difference in reaction and recovery time of clenching for both groups. In conclusion, the satisfaction of implant patients was high, and which was in relation to the successful clinical success criteria and sEMG findings.

  2. Prognosis of Dental Implants Immediately Placed in Sockets Affected by Peri-implantitis: A Retrospective Pilot Study.

    Science.gov (United States)

    Anitua, Eduardo; Piñas, Laura; Begoña, Leire; Alkhraisat, Mohammad Hamdan

    The aim of this study was to describe a protocol and analyze the outcomes of immediate replacement of failed implants due to peri-implantitis. A total of 17 patients (mean age: 58 ± 10 years) had 22 failed implants that were immediately replaced. One implant failed 16 months after insertion, resulting in an implant survival rate of 94.7%. The mean follow-up time was 40 ± 16 months (range: 9-52 months) after insertion. Mesial and distal bone loss were 0.89 ± 0.62 mm and 0.97 ± 0.66 mm, respectively. Immediate implant replacement could be considered in the management of implant failure due to peri-implantitis.

  3. Drug Facts

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  10. Studying the Language Development in Children with Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Marjan Sabri leghaie

    1996-04-01

    Full Text Available Cochlear implant surgery is aimed at making a comprehensive packet of information for the deaf by mixing the data acquired by implanted device and the communicational grammar. Although language production and ability of communication are not main factors in determining the candidacy for cochlear implant surgery, they play crucial role in determining cochlear implant success. we should study the communication skills much deeper than a simple perception and production of speech to have a reasonable evaluation of development of Auditory integration and grammatical language structure. Hence in the current article we will first discuss the grammatical structure in language and then have a look at the pragmatics , semantics and phonological aspects in children with cochlear implant in Virginia college in USA.

  11. Revisiting peri-implant soft tissue – histopathological study of the peri-implant soft tissue

    Science.gov (United States)

    Silva, Eduarda; Félix, Sérgio; Rodriguez-Archilla, Alberto; Oliveira, Pedro; Martins dos Santos, José

    2014-01-01

    Peri-implant soft tissues are essential for osseointegration. The peri-implant mucosa may lack vascular supply, and histological observation, even without plaque, shows the presence of inflammatory cells. The objectives of this study were to assess the histopathological changes of the epithelium and connective tissue around the implant. Twenty patients of both genders were studied. Twelve weeks after implant placement, fragments of peri-implant gingival sulcus were harvested and processed for light microscopy. Group I (10): without clinical inflammatory signs (control); Group II (10): with clinical inflammatory signs. Histopathological parameters were analyzed and classified in 3 grades: mild, moderate or severe (grade 1, 2 or 3). Control group showed only slight changes, grade 1. In group II we found edema with moderate to severe cellular and nuclear changes. There are more women than men with all grades of inflammation. All patients with moderate edema are male and all patients with severe edema are female. A significant association (p=0.007) exists between these two variables. Significant differences were found when comparing the degree of inflammation with nuclear alterations (p=0.001) and the same results when comparing the degree of edema and nuclear changes (pimplant mucosa. In clinics the predisposition of female patients to greater degree of edema and inflammation should be accounted for. PMID:24551281

  12. First Study of Combined Blazar Light Curves with FACT and HAWC

    CERN Document Server

    ,

    2016-01-01

    For studying variable sources like blazars, it is crucial to achieve unbiased monitoring, either with dedicated telescopes in pointing mode or survey instruments. At TeV energies, the High Altitude Water Cherenkov (HAWC) observatory monitors approximately two thirds of the sky every day. It uses the water Cherenkov technique, which provides an excellent duty cycle independent of weather and season. The First G-APD Cherenkov Telescope (FACT) monitors a small sample of sources with better sensitivity, using the imaging air Cherenkov technique. Thanks to its camera with silicon-based photosensors, FACT features an excellent detector performance and stability and extends its observations to times with strong moonlight, increasing the duty cycle compared to other imaging air Cherenkov telescopes. As FACT and HAWC have overlapping energy ranges, a joint study can exploit the longer daily coverage given that the observatories' locations are offset by 5.3 hours. Furthermore, the better sensitivity of FACT adds a fine...

  13. Osseointegration of oral implants after delayed placement in rabbits: a microcomputed tomography and histomorphometric study

    NARCIS (Netherlands)

    Anil, S.; Cuijpers, V.M.J.I.; Preethanath, R.S.; Aldosari, A.A.; Jansen, J.A.

    2013-01-01

    Purpose: This study compared osseointegration of implants placed 14 days after implant site preparation with that of immediately placed implants in rabbit femurs. Materials and Methods: Implants were placed bilaterally in the femoral condyles of 12 rabbits. On one side, the implants were placed 14 d

  14. XANES study of Fe-implanted strontium titanate

    Science.gov (United States)

    Lobacheva, O.; Goncharova, L. V.; Chavarha, M.; Sham, T. K.

    2014-03-01

    Properties of strontium titanate SrTiO3 (STO) depend to a great extent on the substitutional dopants and defects of crystal structure. The ion beam implantation method was used for doping STO (001) crystals with Fe at different doses. Implanted samples were then annealed at 350°C in oxygen to induce recrystallization and remove oxygen vacancies produced during ion implantation process. The effect of Fe doping and post-implantation annealing was studied by X-ray Absorption Near Edge Spectroscopy (XANES) method and Superconducting Quantum Interference Device (SQUID). XANES allowed to monitor the change in structure of STO crystals and in the local environment of Fe following the implantation and annealing steps. SQUID measurements revealed correlation between magnetic moment and Fe implantation dose. Ferromagnetic hysteresis was observed on selected Fe-implanted STO at 5 K. The observed magnetic properties can be correlated with the several Fe oxide phases in addition to the presence of O/Ti vacancies.

  15. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area ​Other Fact Sheets What is structural biology? Structural biology is the study of how biological ...

  16. The combined effects of undersized drilling and implant macrogeometry on bone healing around dental implants: an experimental study.

    Science.gov (United States)

    Jimbo, R; Tovar, N; Anchieta, R B; Machado, L S; Marin, C; Teixeira, H S; Coelho, P G

    2014-10-01

    This study investigated the effect of undersized preparations with two different implant macrogeometries. There were four experimental groups: group 1, conical implant with an undersized osteotomy of 3.2mm; group 2, conical implant with an undersized osteotomy of 3.5mm; group 3, cylindrical implant with an undersized osteotomy of 3.2mm; group 4, cylindrical implant with an undersized osteotomy of 3.5mm. Implants were placed in one side of the sheep mandible (n=6). After 3 weeks, the same procedure was conducted on the other side; 3 weeks later, euthanasia was performed. All implants were 4mm×10mm. Insertion torque was recorded for all implants during implantation. Retrieved samples were subjected to histological sectioning and histomorphometry. Implants of groups 1 and 2 presented significantly higher insertion torque than those of groups 3 and 4 (Pimplant contact or bone area fraction occupied were observed between the groups at 3 weeks (P>0.24, and P>0.25, respectively), whereas significant differences were observed at 6 weeks between groups 1 and 2, and between groups 3 and 4 (Pdental implant macrogeometries.

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

    Science.gov (United States)

    Berglundh, T; Gotfredsen, K; Zitzmann, N U; Lang, N P; Lindhe, J

    2007-10-01

    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. The aim of the current experiment was to study the progression of peri-implantitis around implants with different surface roughness. In five beagle dogs, three implants with either a sandblasted acid-etched surface (SLA) or a polished surface (P) were installed bilaterally 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 and plaque accumulation was continued for an additional 5 months. Radiographs of all implant sites were obtained before and after 'active' experimental peri-implantitis as well as at the end of the experiment. Biopsies were harvested and the tissue samples were prepared for light microscopy. The sections were used for histometric and morphometric examinations. The radiographic examinations indicated that similar amounts of bone loss occurred at SLA and P sites during the active breakdown period, while the progression of bone loss was larger at SLA than at polished sites following ligature removal. The histological examination revealed that both bone loss and the size of the inflammatory lesion in the connective tissue were larger in SLA than in polished implant sites. The area of plaque was also larger at implants with an SLA surface than at implants with a polished surface. It is suggested that the progression of peri-implantitis, if left untreated, is more pronounced at implants with a moderately rough surface than at implants with a polished surface.

  18. Implant survival and patient satisfaction of reduced diameter implants made from a titanium-zirconium alloy: A retrospective cohort study with 550 implants in 311 patients.

    Science.gov (United States)

    Herrmann, Jan; Hentschel, Andreas; Glauche, Ingmar; Vollmer, Armin; Schlegel, Karl Andreas; Lutz, Rainer

    2016-12-01

    The aim of the study was to evaluate implant survival of reduced-diameter implants compared to regular-diameter implants. A retrospective evaluation of 154 Straumann Bone Level Roxolid(®) implants (diameter 3.3 mm) with SLActive(®)-surface in 107 patients, which were inserted between 2009 and 2010 in private practice, was performed. The mean observation period was 22.4 ± 8.2 months. 396 Straumann SLActive(®) implants (4.1 mm and 4.8 mm) in 204 patients, with an observation period of 28.4 ± 10.1 months served as control group. Implant survival rate, resonance frequency analysis and patient satisfaction were evaluated. The implant survival rate was 97.4% in the test vs. 98.5% in the control group. Resonance frequency analysis showed statistically significant lower values for the reduced-diameter implants. Patient satisfaction showed no significant difference between the test and the control group. Reduced-diameter implants displayed high survival rates during the period investigated and represent a convincing treatment alternative. Long-term follow-up investigations confirmed the high implant survival rates of 96.8% (after 69.7 ± 12.3 months) in the test group and 98.5% (after 76.0 ± 13.6 months) in the control group.

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  1. [Advances in the study of virtual channels of cochlear implant].

    Science.gov (United States)

    Zhu, Ziyan; Guan, Tian; Ye, Datian

    2009-12-01

    This paper discusses virtual channels of cochlear implant, which is produced by simultaneous or sequential activation of adjacent cochlear implant electrodes. Virtual channels create and transfer more available spectral pitch information with the limited number of fixed electrodes, which can be recognized as pitch percepts intermediate to those produced by each electrode separately. This technique not only utilizes the interaction of electrodes but also increases the number of place-pitch steps available to cochlear implant listeners. Virtual channels could be used to realize speech recognition in noisy environment, in enjoying music, and in understanding Chinese language. The study of virtual channels would significantly enhance the traditional cochlear implant therapy and benefit people suffering severe to profound hearing loss.

  2. 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.

  3. [Experimental study of osseointegration of zirconium and titanium dental implants].

    Science.gov (United States)

    Kulakov, O B; Doktorov, A A; D'iakova, S V; Denisov-Nikol'skiĭ, Iu I; Grötz, K A

    2005-01-01

    In an experiment performed on pigs, methods of light and scanning electron microscopy were used to study the interaction of zirconium and titanium dental implants with bone 6 months following their insertion. Distinct features of integration of both implant types with bone structures were detected. Sites of direct contact of bone structures with metal were found to undergo constant remodeling according to biochemical and metabolic conditions in each zone of an implant surface. Statistically the degree of interactive properties of zirconium implants significantly exceeded similar parameter for titanium screws. Along the perimeter of the zones of bone contact with zirconium implants greater numbers of forming and formed bone areas were revealed as compared to the zones of bone contact with titanium implants, where erosion lacunae were more numerous. The complex of research methods used in this study have not revealed distinct changes in the structure of osteocytes, located in immediate proximity to the metal surface in comparison with more distant sites in the bone.

  4. The efficacy of flapless implant surgery on soft-tissue profile comparing immediate loading implants to delayed loading implants: A comparative clinical study

    Directory of Open Access Journals (Sweden)

    Ravindran Deepak

    2010-01-01

    Full Text Available Aims and Objectives : To assess the efficacy of flapless implant surgery on soft-tissue profile and to compare the clinical outcomes of flapless implant therapy on immediate loading (IL implants to delayed loading (DL implants. Materials and Methods : The study sample consisted of 20 patients who were partially edentulous in the anterior maxillary region. They were divided into two groups. In group I (IL 10 implants were placed and immediately provisionalized and restored with a metal ceramic crown on the 14th day. In group II (DL 10 implants were placed and loaded after 4 months. Single-piece implants were used for the IL group and two-piece implants were used for the DL group. All soft tissue parameters i.e., modified plaque index (mPI, modified bleeding index (mBI, papillary index (PPI, marginal level of soft tissue (ML and width of keratinized mucosa (WKM were recorded at baseline, Day 60, Day 120 and Day 180. Results: The success rate in group I was found to be 80%, which was lower than the success rate in group II which was found to be 90%. On comparison, there is no statistically significant difference in success rate between the two study groups. There was no statistically significant difference between the groups over time in parameters like mPI, mBI, ML and WKM. The mean PPI score in group II showed a significant increase from when compared to group I. Conclusion: The results of this study indicated that flapless implant surgery using either immediately loading implants or DL implants, demonstrate enhancement of implant esthetics.

  5. In vitro study of magnetic nanoparticles as the implant for implant assisted magnetic drug targeting

    Energy Technology Data Exchange (ETDEWEB)

    Mangual, Jan O.; Aviles, Misael O.; Ebner, Armin D. [Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Ritter, James A., E-mail: ritter@cec.sc.ed [Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2011-07-15

    Magnetic nanoparticle (MNP) seeds were studied in vitro for use as an implant in implant assisted-magnetic drug targeting (IA-MDT). The magnetite seeds were captured in a porous polymer, mimicking capillary tissue, with an external magnetic field (70 mT) and then used subsequently to capture magnetic drug carrier particles (MDCPs) (0.87 {mu}m diameter) with the same magnetic field. The effects of the MNP seed diameter (10, 50 and 100 nm), MNP seed concentration (0.25-2.0 mg/mL), and fluid velocity (0.03-0.15 cm/s) on the capture efficiency (CE) of both the MNP seeds and the MDCPs were studied. The CE of the 10 nm MNP seeds was never more than 30%, while those of the 50 and 100 nm MNP seeds was always greater than 80% and in many cases exceeded 90%. Only the MNP seed concentration affected its CE. The 10 nm MNP seeds did not increase the MDCP CE over that obtained in the absence of the MNP seeds, while the 50 and 100 nm MNP seeds increased significantly, typically by more than a factor of two. The 50 and 100 nm MNP seeds also exhibited similar abilities to capture the MDCPs, with the MDCP CE always increasing with decreasing fluid velocity and generally increasing with increasing MNP seed concentration. The MNP seed size, magnetic properties, and capacity to self-agglomerate and form clusters were key properties that make them a viable implant in IA-MDT. - Highlights: 50-100 nm magnetite nanoparticles can be retained in a porous scaffold using a 70 mT field. Their presence improves the collection efficiency of 0.87 {mu}m magnetic drug carrier particles. Magnetic nanoparticles can thus be used as the implant in implant assisted-magnetic drug targeting.

  6. 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.

  7. Fact and fetish in creolization studies: Herskovits and the problem of induction, or, Guinea Coast, 1593

    Directory of Open Access Journals (Sweden)

    Bill Maurer

    2002-01-01

    Full Text Available Focuses on the way Melville Herkovits used facts and facticity in his scientific work on creolization, and how these facts related to the theories in his work. Author relates this to the idea of fact as a stand-alone datum, or "fetish", independent of any theory for its existence. He describes how Herkovits in his work presented classifications of intensity of African retentions in different parts of the Americas, as well as of cultural elements, which Herkovits meant to be heuristic, yet, the author argues, seemed to precede the data. Further, the author discusses criticisms on this "economic anthropology". In addition, he sketches how the data as fetish, and related induction, developed out of the scientific revolution in Europe, separating arguments from facts, but also out of colonial ventures and the history of the slave trade in West Africa, making it a part of the study of creolization, of African slavery and the African diaspora. He points out, and applaudes, that Herkovits' theoretical stance changed from a strict empiricism to an awareness of the place of argument, or social convention, in the making of the facts themselves.

  8. 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

    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......: 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...... 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...

  9. Fitness for purpose study of the Field Assessment Conditioning Tool (FACT): a research protocol.

    Science.gov (United States)

    MacKinnon, Ralph James; Kennedy, Chris; Doherty, Catherine; Shepherd, Michael; Cole, Joanne; Stenfors-Hayes, Terese

    2015-04-13

    As part of a programme of research aiming to improve the outcomes of traumatically injured children, a multisource healthcare advocacy tool has been developed to allow trauma team members and hospital governance administrators to reflect and to act on complex trauma team-hospital systems interactions. We have termed this tool a Field Assessment Conditioning Tool (FACT). The FACT draws on quantitative data including clinical care points in addition to self-reflective qualitative data. The FACT is designed to provide feedback on this assessment data both horizontally across fellow potential team members and vertically to the hospital/organisation governance structure, enabling process gap identification and allowing an agenda of improvements to be realised. The aim of the study described in this paper is to explore the perceived fitness for purpose of the FACT to provide an opportunity for healthcare advocacy by healthcare professionals caring for traumatically injured children. The FACT will be implemented and studied in three district hospitals, each around a major trauma centre in the UK, USA and New Zealand. Using a qualitative approach with standardised semi-structured interviews and thematic analysis we will explore the following question: Is the FACT fit for purpose in terms of providing a framework to evaluate, reflect and act on the individual hospital's own performance (trauma team-hospital interactions) in terms of readiness to receive traumatically injured children? Ethics opinion was sought for each research host organisation participating and deemed not required. The results will be disseminated to participating sites, networks and published in high-impact journals. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. Quality Rating and Improvement System (QRIS) Validation Study Designs. CEELO FastFacts

    Science.gov (United States)

    Schilder, D.

    2013-01-01

    In this "Fast Facts," a state has received Race to the Top Early Learning Challenge funds and is seeking information to inform the design of the Quality Rating and Improvement System (QRIS) validation study. The Center on Enhancing Early Learning Outcomes (CEELO) responds that according to Resnick (2012), validation of a QRIS is an…

  11. Quality Rating and Improvement System (QRIS) Validation Study Designs. CEELO FastFacts

    Science.gov (United States)

    Schilder, D.

    2013-01-01

    In this "Fast Facts," a state has received Race to the Top Early Learning Challenge funds and is seeking information to inform the design of the Quality Rating and Improvement System (QRIS) validation study. The Center on Enhancing Early Learning Outcomes (CEELO) responds that according to Resnick (2012), validation of a QRIS is an…

  12. Microscopic Study of Surface Microtopographic Characteristics of Dental Implants.

    Science.gov (United States)

    Sezin, M; Croharé, L; Ibañez, J C

    2016-01-01

    To determine and compare the micro topographic characteristics of dental implants submitted to different surface treatments, using scanning electron microscopy (SEM). 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. 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/mm(2) 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). The micro topography observed in the different groups presented dissimilar and specific features, depending on the chemical treatment used for the surfaces..

  13. 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

  14. A Multicentre Study of CLa Implant and Sino-implant Expanded Application (two-year follow-up)

    Institute of Scientific and Technical Information of China (English)

    方可娟; 关艳敏; 范慧民; 高尔生; 杨丹; 薜丽; 韩耀玲; 刘宝

    1997-01-01

    A multicentre comparative clinical study of CLa implant and Sino-implant was carried out at 100 subcentres in 11 provinces, and a total of 19673 subjects were recruited. Two year follow up has been finished. The follow-up rate at the end of two years was 94,29%. Two-year cumulative continuation rate per 100 women for Sino-implant(89.93) was significantly higher than that for CLa implant (88.89). Two-year cumulative pregnancy rates per 100 women were 0.0462(CLa implant) and 0.281(Sino-implant) respectively; there was statistically significant difference between them. No ectopic pregnancy was recorded among CLa implant users and three ectopic pregnancies were reported among Sino implant users,resulting in an ectopic pregnancy rate of 0.163 per 1000 women years. The incidence of side-effects appeared to diminish with time. The major side effects were the menstrual disturbances, which accounted for more than 90% of the total sideeffects, and the incidence of frequent menstruation, irregular bleeding and spotring was higher than that of infrequentjscanty menstruation and amenorrhea. Use of CLa implant had higher incidence of amenorrhea and infrequentjscanty menstruation than that of Sin-imptant. During two-year follow-up, the number of discontinuation due to menstrual problems contributed 78% of the total number of discontinuation; two year menstrual-related cumulative discontinuation rates were 8.96 per 100 women for CLa implant and 7.84 for Sino-implant; there was statistically significant difference(P< 0.01). Two-year study shows that the two types of implant are similar to Norplant in the incidence of side-effects and contraceptive efficacy as well as two year continuation rates.

  15. Comparative Study of Bio-implantable Acoustic Generator Architectures

    Science.gov (United States)

    Christensen, D.; Roundy, S.

    2013-12-01

    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.

  16. Multicenter study with a direct acoustic cochlear implant

    NARCIS (Netherlands)

    Lenarz, T.; Zwartenkot, J.W.; Stieger, C.; Schwab, B.; Mylanus, E.A.M.; Caversaccio, M.; Kompis, M.; Snik, A.F.M.; D'Hondt, C.; Mojallal, H.

    2013-01-01

    OBJECTIVE: To confirm the clinical efficacy and safety of a direct acoustic cochlear implant. STUDY DESIGN: Prospective multicenter study. SETTING: The study was performed at 3 university hospitals in Europe (Germany, The Netherlands, and Switzerland). PATIENTS: Fifteen patients with severe-to-profo

  17. A prospective study of Astra single tooth implants.

    Science.gov (United States)

    Palmer, R M; Smith, B J; Palmer, P J; Floyd, P D

    1997-06-01

    A new design of single tooth implant (AstraTech, Molndal Sweden) featuring a microthreaded conical neck and TiO blast surface was evaluated clinically and radiographically after 2 years in function. Fifteen patients (age range 16 to 48) with missing maxillary anterior teeth (6 central incisors, 8 laterals, 1 bicuspid) had 4, 13 mm and 11, 15 mm implants placed under local anaesthesia and left for a period of 6 months before exposure and abutment connection/crown fabrication. All patients were seen at 4 to 6 monthly intervals for hygienist maintenance. Radiographs using Rinn holders and a long cone technique were taken at the crown insertion and after 1 year (14 subjects) and 2 years (12 subjects). All implants were successfully integrated at stage 2, and no implants have been lost. The internal conical seal design of the abutment/implant interface facilitated connection and there were no cases of abutment screw loosening. No soft tissue problems were observed, and the gingival morphology/health was well maintained. One crown was recemented after 18 months in function, and 1 crown was replaced because of a fracture to the porcelain incisal edge. At crown insertion, the mean bone level was 0.46 to 0.48 mm apical to the top of the implant and there were no statistically significant changes in the bone level over the 2 years of the study. In conclusion, the single tooth Astra implants were highly successful and bone changes within the first 2 years of function were comparable with other systems reporting high long-term success rates.

  18. 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.

  19. Mandibular overdentures supported by two Branemark, IMZ or ITI implants : a 5-year prospective study

    NARCIS (Netherlands)

    Meijer, HJA; Batenburg, RHK; Raghoebar, GM; Vissink, A

    2004-01-01

    Objectives: The aim of this prospective comparative study was to evaluate the survival rate and the condition of the peri-implant tissues of the IMZ implant system (two-stage cylindertype), the Branemark implant system (two-stage screwtype) and the ITI implant system (one-stage screwtype) supporting

  20. The development of nutritional-supplement fact sheets for Irish athletes: a case study.

    Science.gov (United States)

    Pumpa, Kate L; Madigan, Sharon M; Wood-Martin, Ruth E; Flanagan, Richelle; Roche, Noreen

    2012-06-01

    The use of sport supplements presents a dilemma for many of those involved in supporting athletes, including coaches, families, support staff, and the athletes themselves. Often the information that they source can be incorrect and promote a biased view regarding the use of nutritional supplements. The aim of this case study was to describe the process that occurred around the development of a series of targeted educational fact sheets on a range of nutritional supplements for Irish athletes. It describes the initiation and support of the process by the Irish Sports Council; one of its subgroups, the Food and Food Supplements Committee; and the Irish Institute of Sport. A needs assessment through questionnaires was carried out to establish the most commonly used sport nutrition supplements by athletes age 16 or over in Ireland. Respondents completed 105 questionnaires over a 4-mo period in 2008-09 that led to the production of 20 supplement fact sheets. These supplement fact sheets will enable Irish athletes to access high-quality, up-to-date, scientific information about the supplements they have reported consuming. Since personal reading had a strong influence over athletes' decision-making process for taking nutritional supplements, as did scientific research, fact sheets available on the Internet from a reliable source are an ideal way to educate Irish athletes.

  1. Malaria Facts

    Science.gov (United States)

    ... CDC Malaria Branch clinician. malaria@cdc.gov Malaria Facts Recommend on Facebook Tweet Share Compartir Malaria in ... to determine definitively which species are involved. Other Facts Five times, the Nobel Prize in Physiology or ...

  2. Organ Facts

    Science.gov (United States)

    ... Lung Kidney Pancreas Kidney/Pancreas Liver Intestine Organ Facts Here you can find valuable information about organs ... Camps for kids Contacting my donor family Data Facts about living donation Financing a transplant Matching organs ...

  3. Kidney Facts

    Science.gov (United States)

    ... Lung Kidney Pancreas Kidney/Pancreas Liver Intestine Kidney Facts The kidneys are a pair of reddish-brown ... Camps for kids Contacting my donor family Data Facts about living donation Financing a transplant Matching organs ...

  4. Liver Facts

    Science.gov (United States)

    ... Lung Kidney Pancreas Kidney/Pancreas Liver Intestine Liver Facts How the Liver Works The liver is one ... Camps for kids Contacting my donor family Data Facts about living donation Financing a transplant Matching organs ...

  5. Cochlear Implants in the Inclusive Classroom: A Case Study

    Science.gov (United States)

    Jachova, Zora; Kovacevic, Jasmina

    2010-01-01

    This article presents a case study of a child aged 12 years with a cochlear implant who is attending a mainstream educational setting in Skopje, FYR Macedonia. The study, which uses both qualitative and quantitative data, took place over a period of 12 months. It illustrates the importance of professional development and training of teachers and a…

  6. Lattice location study of implanted In in Ge

    CERN Document Server

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

    2009-01-01

    We report on emission channeling experiments to determine the lattice location and the thermal stability of implanted $^{111}$In atoms in Ge. The majority of the In atoms was found on the substitutional site, which is a thermally stable site at least up to 500 °C. We also found strong indication that directly after implantation, a fraction of the implanted $^{111}$In atoms occupies the bond-centered BC site. This fraction disappears after annealing at 300 °C. From comparison with ab initio calculations, electrical studies, and perturbed angular correlation experiments, the In atoms on the BC site can be related to In-vacancy and In-self-interstitial defect complexes. The activation energy for dissociation of this BC related defect was found to be below 1.6 eV.

  7. 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.

  8. Study of ion implantation profiles by the PIXE technique

    Science.gov (United States)

    Midy, P.; Lagarde, G.; Brissaud, I.; Frontier, J. P.; Chaumont, J.

    1998-03-01

    The RBS technique is currently used with alpha particles as a non-destructive way of studying concentration depth profiles. This technique is especially convenient in characterizing heavy atom distributions inside a matrix of lighter elements, and its use is less convenient in the case of light elements in a matrix of heavier ones. On the other hand the probing depth is limited by the small range of alpha particles in the matrix. We present here a new procedure for determining ion implantation profiles by means of the PIXE technique and by varying the impinging proton energy. As an example, silicon ions of two energies have been implanted into pure titanium samples in order to obtain implantation profiles with a double peak. The results presented here are in good agreement with the calculations using the TRIM code.

  9. Impact of Crown-Implant Ratio of Single Restorations Supported by 6-mm Implants : A Short-Term Case Series Study

    NARCIS (Netherlands)

    Guljé, Felix L; Raghoebar, Gerry M; Erkens, Ward Al; Meijer, Henny Ja

    2016-01-01

    PURPOSE: High crown-implant ratios might affect the biologic and technical performance of a reconstruction. The aim of this study was to assess whether a higher crown-implant ratio of single restorations on 6-mm implants resulted in more peri-implant bone loss and more prosthetic complications durin

  10. Early radiographic diagnosis of peri-implantitis enhances the outcome of peri-implantitis treatment: a 5-year retrospective study after non-surgical treatment

    OpenAIRE

    Chang, Hee-Yung; Park, Shin-Young; Kim, Jin-Ah; Kim, Young-Kyun; Lee, Hyo-Jung

    2015-01-01

    Purpose This retrospective study evaluated the relationship between the timing of peri-implantitis diagnosis and marginal bone level after a 5-year follow-up of non-surgical peri-implantitis treatment. Methods Thirty-three patients (69 implants) were given peri-implantitis diagnosis in 2008-2009 in Seoul National University Bundang Hospital. Among them, 31 implants from 16 patients were included in this study. They were treated non-surgically in this hospital, and came for regular maintenance...

  11. 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...

  12. Investigation of Pathogenic Genes in Peri-Implantitis from Implant Clustering Failure Patients: A Whole-Exome Sequencing Pilot Study

    Science.gov (United States)

    Lee, Soohyung; Kim, Ji-Young; Hwang, Jihye; Kim, Sanguk; Lee, Jae-Hoon; Han, Dong-Hoo

    2014-01-01

    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 implant failure. This result may demonstrate the feasibility of and provide pilot data for a larger research project aimed at discovering biomarkers for early diagnosis of peri-implantitis. PMID:24921256

  13. Bone Response to Surface-Modified Titanium Implants: Studies on the Early Tissue Response to Implants with Different Surface Characteristics

    Directory of Open Access Journals (Sweden)

    C. Larsson Wexell

    2013-01-01

    Full Text Available In a series of experimental studies, the bone formation around systematically modified titanium implants is analyzed. In the present study, three different surface modifications were prepared and evaluated. Glow-discharge cleaning and oxidizing resulted in a highly stoichiometric TiO2 surface, while a glow-discharge treatment in nitrogen gas resulted in implants with essentially a surface of titanium nitride, covered with a very thin titanium oxide. Finally, hydrogen peroxide treatment of implants resulted in an almost stoichiometric TiO2, rich in hydroxyl groups on the surface. Machined commercially pure titanium implants served as controls. Scanning Auger Electron Spectroscopy, Scanning Electron Microscopy, and Atomic Force Microscopy revealed no significant differences in oxide thickness or surface roughness parameters, but differences in the surface chemical composition and apparent topography were observed. After surface preparation, the implants were inserted in cortical bone of rabbits and evaluated after 1, 3, and 6 weeks. Light microscopic evaluation of the tissue response showed that all implants were in contact with bone and had a large proportion of newly formed bone within the threads after 6 weeks. There were no morphological differences between the four groups. Our study shows that a high degree of bone contact and bone formation can be achieved with titanium implants of different surface composition and topography.

  14. PET studies of parkinsonian patients treated with autologous adrenal implants.

    Science.gov (United States)

    Guttman, M; Burns, R S; Martin, W R; Peppard, R F; Adam, M J; Ruth, T J; Allen, G; Parker, R A; Tulipan, N B; Calne, D B

    1989-08-01

    Transplantation of autologous adrenal medulla tissue into the striatum has recently been proposed as a treatment for Parkinson's disease. We report the use of positron emission tomography (PET) to evaluate patients who had adrenal implants placed into the right caudate. 6-[18F] fluoro-L-dopa (6-FD) scans were performed to study the integrity and activity of the implant, and the nigrostriatal dopamine system before and six weeks after transplantation surgery. [68Ga] Gallium-ethylenediaminetetraacetate (Ga) scans were also performed to assess the blood brain barrier. The Ga scans performed on two patients showed increased permeability of the blood brain barrier at the surgical site. 6-FD PET scans in five patients did not show a consistent change in striatal uptake following adrenal medullary implantation after six weeks. Further assessment of implant viability with 6-FD PET scans after longer follow up may provide useful information if the blood-brain barrier becomes re-established with the passage of time.

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

    NARCIS (Netherlands)

    Zon, A. van; Smulders, Y.E.; Ramakers, G.G.; Stegeman, I.; Smit, A.L.; Zanten, G.A.; Stokroos, R.J.; Hendrice, N.; Free, R.H.; Maat, B.; Frijns, J.H.; Mylanus, E.A.M.; Huinck, W.J.; Topsakal, V.; Tange, R.A.; Grolman, W.

    2016-01-01

    OBJECTIVES/HYPOTHESIS: To 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 DESIGN: Prospective study. MET

  16. Clinical evaluation of short 6-mm implants alone, short 8-mm implants combined with osteotome sinus floor elevation and standard 10-mm implants combined with osteotome sinus floor elevation in posterior maxillae: study protocol for a randomized controlled trial

    OpenAIRE

    Shi, Jun-Yu; Gu, Ying-Xin; Qiao, Shi-Chong; Zhuang, Long-Fei; Zhang, Xiao-Meng; Lai, Hong-Chang

    2015-01-01

    Background Nowadays, short dental implants are being increasingly applied in extremely resorbed posterior regions. The recent studies have indicated that short implants present a similar success rate to conventional implants. It is assumed that short implants can avoid additional surgical morbidity and are less technically demanding. However, high-quality evidence (≥Ib: evidence from at least one randomized controlled trial) on comparing the clinical outcome of short implants and longer impla...

  17. 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.

  18. Efficacy Study of a Fully Implanted Neuroprosthesis for Functional Benefit to Individuals with Tetraplegia

    Science.gov (United States)

    2016-10-01

    modules (stimulators, biopotential recording) for the NNP. As a result, it may require more time to fabricate a complete set for implantation, but we...for our research subjects that is adjacent to our rehabilitation hospital and to our research laboratories . This facility essentially serves as a...this additional information and, in fact, cannot be completed without it. We will continue to report on these implantation procedures to keep the

  19. Leakage of Microbial Endotoxin through the Implant-Abutment Interface in Oral Implants: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Rhoodie Garrana

    2016-01-01

    Full Text Available Background. Endotoxin initiates osteoclastic activity resulting in bone loss. Endotoxin leakage through implant abutment connections negatively influences peri-implant bone levels. Objectives. (i To determine if endotoxin can traverse different implant-abutment connection (IAC designs; (ii to quantify the amount of endotoxins traversing the IAC; (iii to compare the in vitro comportments of different IACs. Materials and Methods. Twenty-seven IACs were inoculated with E. coli endotoxin. Six of the twenty-seven IACs were external connections from one system (Southern Implants and the remaining twenty-one IACs were made up of seven internal IAC types from four different implant companies (Straumann, Ankylos, and Neodent, Southern Implants. Results. Of the 27 IACs tested, all 6 external IACs leaked measurable amounts of endotoxin. Of the remaining 21 internal IACs, 9 IACs did not show measurable leakage whilst the remaining 12 IACs leaked varying amounts. The mean log endotoxin level was significantly higher for the external compared to internal types (p=0.015. Conclusion. Within the parameters of this study, we can conclude that endotoxin leakage is dependent on the design of the IAC. Straumann Synocta, Straumann Cross-fit, and Ankylos displayed the best performances of all IACs tested with undetectable leakage after 7 days. Each of these IACs incorporated a morse-like component in their design. Speculation still exists over the impact of IAC endotoxin leakage on peri-implant tissues in vivo; hence, further investigations are required to further explore this.

  20. Leakage of Microbial Endotoxin through the Implant-Abutment Interface in Oral Implants: An In Vitro Study.

    Science.gov (United States)

    Garrana, Rhoodie; Mohangi, Govindrau; Malo, Paulo; Nobre, Miguel

    2016-01-01

    Background. Endotoxin initiates osteoclastic activity resulting in bone loss. Endotoxin leakage through implant abutment connections negatively influences peri-implant bone levels. Objectives. (i) To determine if endotoxin can traverse different implant-abutment connection (IAC) designs; (ii) to quantify the amount of endotoxins traversing the IAC; (iii) to compare the in vitro comportments of different IACs. Materials and Methods. Twenty-seven IACs were inoculated with E. coli endotoxin. Six of the twenty-seven IACs were external connections from one system (Southern Implants) and the remaining twenty-one IACs were made up of seven internal IAC types from four different implant companies (Straumann, Ankylos, and Neodent, Southern Implants). Results. Of the 27 IACs tested, all 6 external IACs leaked measurable amounts of endotoxin. Of the remaining 21 internal IACs, 9 IACs did not show measurable leakage whilst the remaining 12 IACs leaked varying amounts. The mean log endotoxin level was significantly higher for the external compared to internal types (p = 0.015). Conclusion. Within the parameters of this study, we can conclude that endotoxin leakage is dependent on the design of the IAC. Straumann Synocta, Straumann Cross-fit, and Ankylos displayed the best performances of all IACs tested with undetectable leakage after 7 days. Each of these IACs incorporated a morse-like component in their design. Speculation still exists over the impact of IAC endotoxin leakage on peri-implant tissues in vivo; hence, further investigations are required to further explore this.

  1. Effects of local administration of growth hormone in peri-implant bone: an experimental study with implants in rabbit tibiae.

    Science.gov (United States)

    Tresguerres, Isabel F; Blanco, Luis; Clemente, Celia; Tresguerres, Jesús A F

    2003-01-01

    The objective of this study was to evaluate the qualitative and quantitative differences that could appear in newly formed peri-implant bone around Screw-Vent implants placed in rabbit tibiae when treated with local administration of growth hormone (GH). Eight New Zealand rabbits were randomly divided into 2 groups: the experimental group, which received 4 IU of GH in the form of lyophilized powder added to the ostectomy site before implant placement, and the control group, which did not receive GH before implant placement. Animals were sacrificed 2 weeks later, and histologic sections were obtained for histomorphometry and observation under light microscopy. The sections in the GH-treated group presented enhanced growth of new trabeculae from the periosteal tissue, and the bone-to-implant contact in the experimental group was significantly greater (P < .05). Local administration of GH stimulated a more dramatic effect than that seen previously with systemic GH administration, prompting growth from both the periosteum and endosteum. Local administration of GH at the time of implant placement could enhance peri-implant bone reaction.

  2. Immediate implant loading with fixed dental restorations: An animal model study

    Directory of Open Access Journals (Sweden)

    Špadijer-Gostović Aleksandra

    2012-01-01

    Full Text Available Background/Aim. Immediate loading is considered to be the most innovative technique in contemporary implant dentistry. Recent clinical and experimental findings have demonstrated that only implants with high primary stability can be subjected to immediate loading protocol with predictable results. It is generally accepted that the most important prerequsite for successful osseointegration is achievement and maintenance of implant stability. The aim of this in vivo study was to investigate the possibility for successful application of immediate loading protocol in implant systems with different surface properties. Methods. In the experimental study 2 mongrel dogs were edentulated bilaterally in the mandibular and maxillary premolar areas. After 3 months implants were placed in a pattern 4 different commercially available implants per quadrant (n = 32: Mk III TiUnite (Nobel Biocare, Sweden, ITI TPS (Straumann, Switzerland, 3IOsseotite (Implant Innovation, USA and XiVE Cell-Plus (Friadent, Germany. Implants were subjected to immediate loading with 4 unit gold cast bridges, 2 days post implantation. The assessment of implant stability and immediate loading possibilities were done by performing Resonance frequency analysis (RFA. Results. After a 6- month loading period all bridges were in function and all implants occurred well osseointegrated. When summarizing the Implant Stability Quotient (ISQ values, it was noted that resonance frequency was significantly higher for mandibular implants. The results of this experimental setting showed that all evaluated surfaces achieved good implant stability. Increase of ISQ values was found for all implants in the mandible and partially decrease of ISQ values for maxillary implants after 6 months of functional loading with 4 unit bridges. Conclusions. Investigated endooseal implants did not show different degree of osseointegration, because there was not statisticaly significant difference among observed

  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. 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.

  5. Feasibility study to damp power system multi-mode oscillations by using a single FACTS device

    Energy Technology Data Exchange (ETDEWEB)

    Du, W.; Wu, X. [School of Electrical Engineering, Southeast University, Nanjing (China); Wang, H.F. [School of Electronics, Electrical Engineering and Computer Science, The Queen' s University of Belfast, Belfast BT7 1NN (United Kingdom); Dunn, R. [University of Bath, Bath (United Kingdom)

    2010-07-15

    To damp power system multi-mode oscillations, the commonly-used method is to arrange multiple decentralized stabilizers, such as PSS (Power System Stabilizer) and FACTS (Flexible AC Transmission Systems) stabilizers. In order to overcome the problem of interactions between stabilizers, coordinated design of multiple decentralized stabilizers has been proposed to simultaneously set parameters of all stabilizers. However, in practice it could be very difficult to implement the coordinated design of multiple stabilizers. This is because those stabilizers are often at different geographical locations in a power system and cross-location simultaneous field tuning of stabilizers' parameters is a tremendous task due to their interactions. Hence this paper proposes a novel scheme of damping power system multi-mode oscillations by using a single FACTS device and presents the results of feasibility study of the proposed scheme. It is demonstrated that multiple stabilizers can be arranged in a single FACTS device to effectively damp power system multi-mode oscillations. Under this scheme, multiple stabilizers are at a same geographical location in the power system and hence their parameters can be tuned simultaneously in coordination in the field. In the paper, three examples of multi-machine power systems installed with a UPFC (Unified Power Flow Controller), a STATCOM (Static Synchronous Compensator)/BESS (Battery Energy Storage System) and a MUPFC (Multiple-terminal UPFC) respectively are presented. Parameters of multiple stabilizers are designed in coordination by using a newly appeared method of optimisation-artificial fish swarm algorithm. Simulation results in the paper are compared with those obtained from applying the conventional scheme of decentralized control involving multiple PSSs. They demonstrate and confirm the feasibility of proposed scheme in the paper. (author)

  6. Studying Herpesvirus Pathogenesis Using SCID Mice Implanted With Human Tissues

    Institute of Scientific and Technical Information of China (English)

    Marvin; Sommer; Shannon; Taylor; Stacey; Leisenfelder; Robert; Morton; Ann; Arvin; Jennifer; Moffat

    2005-01-01

    Human cytomegalovirus(HCMV)and Varicella Zoster virus(VZV)are belongto herpesvirusfamily.HCMVrarelycaus-es symptomatic diseaseinanimmunocompetent host;however,itis a major cause of infectious morbidityand mortalityinimmunocompromised individuals and developingfetuses.VZVinfectioncauses chickenpoxandshingles.Sincethese spe-cies-specific herpesviruses do notinfect other animals,noanimal model is availablefor pathogenesis studies.Severe com-binedimmunodeficient(SCID)mice implanted with humantissues(SCID-hu)pro...

  7. Impact of dental implant insertion method on the peri-implant bone tissue--an experimental study.

    Science.gov (United States)

    Stamatović, Novak; Matić, Smiljana; Tatić, Zoran; Petković-Curcin, Aleksandra; Vojvodić, Danilo; Rakić, Mia

    2013-09-01

    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. 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. 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 osteocytes in 3 specimens. No necrotic tissue was found. The analyzed specimens of bone adjacent to two-stage implants revealed a moderate increase in the number of osteocytes in 3 and a marked increase in 6 specimens respectively. This difference was statistically significant (Wb = 106.5 > 105, alpha = 0.05). No necrosis and osteoblastic activity were observed. 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

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

    Science.gov (United States)

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

    2016-12-01

    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, 10units), Ti_Ag (silver electrodeposition treatment, 10units), and Ti_TSP (silanization treatment, 10units). 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 2months 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 (Pimplant 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Facts and artifacts in studies of gene expression in aneuploids and sex chromosomes.

    Science.gov (United States)

    Birchler, James A

    2014-10-01

    Studies of gene expression in aneuploids have often made the assumption that measurements of RNA abundance from the varied chromosome will establish whether there is a dosage effect or compensation. Typical procedures of RNA isolation and use of equal amounts of RNA for quantitative estimates will not measure the total transcriptome size nor the absolute expression levels per cell. Use of internal endogenous standards or averages from unvaried chromosomes for normalizations makes the assumption that there are no global modulations across the genome. However, studies that use controls to test these assumptions reveal that there are in fact often modulations on all chromosomes. The same caveats apply to gene expression studies of sex chromosomes, which also involve changes in dosage of a small portion of the genome. Here, we describe some of the pitfalls of studies of aneuploidy and sex chromosome gene expression and review methods that have been used to avoid them.

  10. 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.

  11. Drug Facts

    Medline Plus

    Full Text Available ... and Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and symptoms of ... to Drugs? Does Addiction Run in Families? Why Is It So Hard to Quit Drugs? Effects of ...

  12. Drug Facts

    Medline Plus

    Full Text Available ... Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and symptoms of someone ... use problem? How Does Drug Use Become an Addiction? What Makes Someone More Likely to Get Addicted ...

  13. Fact Sheets

    Science.gov (United States)

    ... Fact Sheets are available in both English and Spanish and can be downloaded for free. Currently available ... Antiviral Medications to Treat or Prevent Influenza (the Flu) PDF | Espanol PDF Apremilast (Otezla®) PDF | Espanol PDF ...

  14. Ferret facts

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This update functions to inform cooperators on the latest, most recent facts on the 1994 Montana Black-footed Ferret Reintroduction. This is a weekly update,...

  15. Drug Facts

    Medline Plus

    Full Text Available ... Nicotine Facts Other Drugs of Abuse What is Addiction? Do You or a Loved One Have a Drug Use Problem? Signs of Drug Use and Addiction How Does Drug Use Become Addiction? Addiction Risk ...

  16. Drug Facts

    Medline Plus

    Full Text Available ... The Link Between Drug Use and HIV/AIDS Recovery & Treatment Drug Treatment Facts Does Drug Treatment Work? ... and Family Can Help Find Treatment/Rehab Resources Prevent Drug Use Help Children and Teens Stay Drug- ...

  17. DLTS and EPR study of defects in H implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Miksic, V.; Pivac, B. E-mail: pivac@rudjer.irb.hr; Rakvin, B.; Zorc, H.; Corni, F.; Tonini, R.; Ottaviani, G

    2002-01-01

    Single crystal CZ Si samples were implanted with hydrogen ions to the dose of 2E16 He ions/cm{sup 2} at room temperature and subsequently annealed in vacuum in the temperature interval from 100 to 900 deg. C. The aim of the experiment was to determine the conditions for bubble formation within the solid film, which may have important technological application. Defects produced in such samples were studied by deep-level transient spectroscopy (DLTS) and electron paramagnetic resonance (EPR) spectroscopy. It is shown that high dose hydrogen implantation produces vacancy-related and silicon selfinterstitial clusters. The latter are thought to be responsible for the formation of the weak displacement field. The annealing at higher temperatures creates multivacancy-related clusters responsible for the strong displacement field formation.

  18. One-step surgical placement of Brånemark implants: a prospective multicenter clinical study.

    Science.gov (United States)

    Becker, W; Becker, B E; Israelson, H; Lucchini, J P; Handelsman, M; Ammons, W; Rosenberg, E; Rose, L; Tucker, L M; Lekholm, U

    1997-01-01

    This prospective longitudinal multicenter study evaluated the clinical outcomes after placement and restoration of one-step Brånemark implants into the maxillae and mandibles of completely and partially edentulous patients. Six surgical treatment centers participated in this study, in which 135 implants were placed into 63 adult patients. All implants were stable after placement. The majority of implants were placed into type B bone with minimal jaw resorption and type 2 bone quality. After implant placement, standard transmucosal healing abutments were firmly placed. The average amount of time between implant placement and prosthetic abutment connection was 170 days in the maxillae and 147 days in the mandibles. To evaluate crestal bone changes caused by implant placement, a periodontal probe was used to measure midbuccally from the top of the implant cylinder to the alveolar crest; in 29 patients, 54 midbuccal bone crest sites were remeasured following prosthetic abutment connection. Crestal bone changes in mandibles and maxillae were statistically and clinically insignificant. Six implants were lost prior to loading and one implant has not been restored. No implants or restorations were lost after loading. At 1 year, the implant success rate was 95.6%. Mesiodistal radiographic measurements from 34 patients were averaged, and changes from prosthetic abutment connection to, on average, 12 months follow-up were compared. The radiographs, which were digitalized, measured from the bottom of the implant cylinder to the most coronal bone in contact with implant thread. For mandibular implants, the mean radiographic bone level at prosthetic abutment connection was 1.07 mm; after loading, it was 1.35 mm. For maxillary implants, the mean radiographic bone height at prosthetic abutment connection was 1.16 mm; after loading, it was 1.36 mm. These changes were not statistically significant. The 1-year outcomes from this patient series indicate that one-step Br

  19. In vitro study of reduction of stress transferred onto tissues around implants using a resilient material in maxillary implant overdentures.

    Science.gov (United States)

    Kanazawa, Manabu; Minakuchi, Shunsuke; Hayakawa, Iwao; Hirano, Shigezo; Uchida, Tatsuro

    2007-03-01

    The purpose of this in vitro study was to investigate the effect of hardness on the reduction of stress transferred to tissues around implants using a resilient material applied to the female parts of the ball attachment in maxillary implant overdentures. A cast chrome-cobalt framework was mounted onto a maxillary acrylic edentulous model, which contained two implants and four strain gauges attached to the implant. Ball abutments were screwed into the implant. One abutment was connected to a dedicated metal cap embedded in the housing, while the others were connected to resilient test materials with four different hardnesses. Loads were applied using a universal testing machine with a magnitude of 50 N. The sums of the absolute values recorded from the four strain gauges were used for stress evaluation. The measured strains were analyzed statistically using two-way ANOVA and multiple comparisons. A resilient material with hardness 90 exhibited strains that did not differ significantly from the control. In contrast, the other resilient materials showed significantly reduced strains under all conditions. In this limited study, application of resilient silicone materials with approximate hardness 80 to the female parts of ball attachments significantly reduced the stress on the tissues around the implant.

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

    DEFF Research Database (Denmark)

    Gallardo, Maria Godoy; Manzanares-Céspedes, Maria Cristina; Sevilla, Pablo

    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...

  1. Outcomes of FLEXIBLE Assertive Community Treatment (FACT) Implementation: A Prospective Real Life Study.

    Science.gov (United States)

    Nugter, M Annet; Engelsbel, Fabiana; Bähler, Michiel; Keet, René; van Veldhuizen, Remmers

    2016-11-01

    This study aimed to investigate social and clinical outcomes and use of care during and after implementation of FLEXIBLE Assertive Community Treatment (ACT). Three teams and 372 patients were involved. Model fidelity, clinical and social assessments were performed at baseline and after 1 and 2 years. Use of care was registered continuously. Model fidelity was good at the end of the study. Data showed much variation between patients in number and duration of ACT periods. Statistically significant improvements were found in compliance, unmet needs and quality of life. Improvement of quality of life and functioning was related to duration of ACT. The percentage of remissions increased with 9 %. The number of admissions, admission days and face to face contacts differed between ACT and non-ACT patients, but generally decreased. Findings suggest that implementation of FACT results in a more flexible adaptation of care to the needs of the patients.

  2. 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

  3. 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

    2016-01-01

    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 characteristic

  4. 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

  5. Study on the neotype zirconia's implant coated nanometer hydroxyapatite ceramics

    Science.gov (United States)

    Zhu, J. W.; Yang, D. W.

    2007-07-01

    In recent years, biologic ceramics is a popular material of implants and bioactive surface modification of dental implant became a research emphasis, which aims to improve bioactivity of implants materials and acquire firmer implants-bone interface. The zirconia ceramic has excellent mechanical properties and nanometer HA ceramics is a bioceramic well known for its bioactivity, therefore, nanometer HA ceramics coating on zirconia, allows combining the excellent mechanical properties of zirconia substrates with its bioactivity. This paper shows a new method for implant shape design and bioactive modification of dental implants surface. Zirconia's implant substrate was prepared by sintered method, central and lateral tunnels were drilled in the zirconia hollow porous cylindrical implants by laser processing. The HA powders and needle-like HA crystals were made by a wet precipitation and calcining method. Its surface was coated with nanometer HA ceramics which was used brush HA slurry and vacuum sintering. Mechanical testing results revealed that the attachment strength of nanometer HA ceramics coated zirconia samples is high. SEM and interface observation after inserted experiment indicated that calcium and phosphor content increased and symmetrically around coated implant-bone tissue interface. A significantly higher affinity index was demonstrated in vivo by histomorphometric evaluation in coated versus uncoated implants. SEM analysis demonstrated better bone adhesion to the material in coated implant at any situation. In addition, the hollow porous cylindrical implant coated with nanometer HA ceramics increase the interaction of bone and implant, the new bone induced into the surface of hollow porous cylindrical implant and through the most tunnels filled into central hole. The branch-like structure makes the implant and bone a body, which increased the contact area and decreased elastic ratio. Therefore, the macroscopical and microcosmic nested structure of

  6. Bone healing at implants with a fluoride-modified surface: an experimental study in dogs.

    Science.gov (United States)

    Berglundh, T; Abrahamsson, I; Albouy, J-P; Lindhe, J

    2007-04-01

    The aim of the present experiment was to study early stages of osseointegration to implants with a fluoride-modified surface. Six mongrel dogs, about 1-year old, were used. All mandibular premolars and the first mandibular molars were extracted. Three months later, mucoperiosteal flaps were elevated in one side of the mandible and six sites were identified for implant placement. The control implants (MicroThread) had a TiOblast surface, while the test implants (OsseoSpeed) had a fluoride-modified TiOblast surface. Both types of implants had a similar geometry, a diameter of 3.5 mm and were 8 mm long. Following installation, cover screws were placed and the flaps were adjusted and sutured to cover all implants. Four weeks after the first implant surgery, the installation procedure was repeated in the opposite side of the mandible. Two weeks later, biopsies were obtained and prepared for histological analysis. The void that occurred between the cut bone wall of the recipient site and the macro-threads of the implant immediately following implant installation was used to study early bone formation. It was demonstrated that the amount of new bone that formed in the voids within the first 2 weeks of healing was larger at fluoride-modified implants (test) than at TiOblast (control) implants. It was further observed that the amount of bone-to-implant contact that had been established after 2 weeks in the macro-threaded portion of the implant was significantly larger at the test implants than at the controls. It is suggested that the fluoride-modified implant surface promotes osseointegration in the early phase of healing following implant installation.

  7. An accuracy study of computer-planned implant placement in the augmented maxilla using osteosynthesis screws.

    Science.gov (United States)

    Verhamme, L M; Meijer, G J; Soehardi, A; Bergé, S J; Xi, T; Maal, T J J

    2017-04-01

    Previous research on the accuracy of flapless implant placement of virtually planned implants in the augmented maxilla revealed unfavourable discrepancies between implant planning and placement. By using the osteosynthesis screws placed during the augmentation procedure, the surgical template could be optimally stabilized. The purpose of this study was to validate this method by evaluating its clinically relevant accuracy. Twelve consecutive fully edentulous patients with extreme resorption of the maxilla were treated with a bone augmentation procedure. Virtual implant planning was performed and a surgical template was manufactured. Subsequently, six implants were installed using the surgical template, which was only supported by the osteosynthesis screws. Implant deviations between planning and placement were calculated. A total of 72 implants were installed. Mean deviations found in the mesiodistal direction were 0.817mm at the implant tip and 0.528mm at the implant shoulder. The angular deviation was 2.924°. In the buccolingual direction, a deviation of 1.038mm was registered at the implant tip and 0.633mm at the implant shoulder. The angular deviation was 3.440°. This study showed that implant placement in the augmented maxilla using a surgical template supported by osteosynthesis screws is accurate.

  8. Immediate loading of immediate mandibular implants with a full-arch fixed prosthesis: a preliminary study.

    Science.gov (United States)

    Peñarrocha, Miguel; Boronat, Araceli; Garcia, Berta

    2009-06-01

    To determine the survival of immediate dental implants with immediate loading in the partially edentulous mandible, by use of a full-arch screw-retained provisional restoration. Patients who were partially edentulous in the mandible with indications for extraction of the remaining teeth and with a minimum follow-up of 12 months after implant placement were included in the study. They were treated in chronologic order by the insertion of 6 Defcon dental implants (Impladent, Sentmenat, Spain) subjected to immediate loading (4 interforaminal and 2 posterior placements). Implants with a minimum primary stability of 60 implant stability quotient were loaded. All resin screw-retained prostheses were inserted and loaded with fully functional occlusion within 24 hours of implant placement. Eleven patients were treated with immediate implants, although 2 patients were excluded from the study for having an implant stability quotient value below 60 in at least one of the implants after surgery and did not undergo restoration with immediate loading. Fifty-four implants were placed in 9 partially edentulous patients with immediate loading with a full-arch screw-fixed prosthesis. The patients wore this provisional prosthesis during the healing period (2 months) without complication and with a high level of comfort. The survival rate of the implants was 100% at 12 months of follow-up. Immediate mandibular loading with immediate full-arch implant-supported and screw-retained restorations is a viable treatment alternative, yielding a 100% success rate in this small series of patients.

  9. Effect of tilted and short distal implants on axial forces and bending moments in implants supporting fixed dental prostheses: an in vitro study.

    Science.gov (United States)

    Ogawa, Toru; Dhaliwal, Sandra; Naert, Ignance; Mine, Atsushi; Kronstrom, Mats; Sasaki, Keiichi; Duyck, Joke

    2010-01-01

    The aim of this study was to evaluate the axial forces (AFs) and bending moments (BMs) on implants supporting a fixed dental prosthesis (FDP) with a distal cantilever (10 mm) compared to an FDP supported by a tilted or short (7 mm instead of 13 mm) posterior implant by means of in vitro strain gauge measurements. Nine titanium Branemark implants were placed in an edentulous composite mandible. The mechanical loading conditions were evaluated for the following three situations: (1) short distal implants supporting a cantilever, (2) long tilted distal implants, and (3) no distal implants supporting a cantilever. A vertical load of 50 N was applied at the first molar position, and the resultant AFs and BMs were measured for the three different situations, three different numbers of supporting implants (three, four, or five), and three different prosthesis materials (titanium, acrylic, and fiber-reinforced acrylic). The mean BMs, as well as the maximum AFs and BMs, were significantly higher in the model with a cantilever compared to that having the tilted or short distal implants (P models with a distally tilted implant versus a short distal implant. The use of posterior implants reduced the AFs and BMs on implants supporting an FDP compared to that with a distal cantilever. No difference in mechanical loading was observed between short tilted distal implants.

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

    NARCIS (Netherlands)

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

    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 participat

  11. [PRIMARY STUDY ON IMPLANT COVERAGE WITH LOCAL SOFT TISSUE IN IMMEDIATE IMPLANT-BASED BREAST RECONSTRUCTION].

    Science.gov (United States)

    Li, Guangxue; Mu, Lan; Liu, Yan; Yang, Kai; Peng, Zhe; Bi, Ye

    2016-03-01

    To explore the method of implant coverage with local soft tissue in immediate implant-based breast reconstruction and to evaluate the early effectiveness. Between April 2014 and August 2015, 11 patients with breast cancer underwent immediate breast reconstruction with implants after mastectomy, and the clinical data were reviewed retrospectively. The age ranged 29-48 years (mean, 36 years). The disease duration was from 7 days to 12 months (median, 3 months). According to tumor staging, 3 cases were rated as T(is)N0M0, 4 cases as T1N0M0, and 4 cases as T2N0M0. The implants were covered with local soft tissue according to the volume of mastectomy and contralateral breast size, including pectoralis major myocutaneous flaps with inframammary adipofasical flaps (3 cases), with serratus anterior fascial flap (5 cases), with rectus sheath fascial flap (1 case), and with serratus anterior fascial flap and rectus sheath fascial flap (2 cases). The size of pectoralis major myocutaneous flaps ranged from 15 cm x 9 cm to 20 cm x 15 cm, and the serratus anterior fascial flaps from 10 cm x 8 cm to 15 cm x 10 cm, and the rectus sheath fascial flap from 8 cm x 6 cm to 10 cm x 8 cm. One patient had partial nipple necrosis postoperatively and was cured, and no other postoperative complications of hematoma, infection, or implant exposure was found. The patients were followed up 4-13 months (median, 8 months). The reconstructive outcomes were excellent in 10 cases and good in 1 case, with an excellent and good rate of 100%. During follow-up, no rupture or exposure of the implant was observed; capsular contracture (Baker grade II) occurred in 1 case. Adequate coverage of implants with different local soft tissue flaps can achieve satisfactory early effectiveness in immediate implant-based breast reconstruction after mastectomy.

  12. Snack, Facts

    Science.gov (United States)

    Smith, Suzanne M.

    2005-01-01

    The American diet has undergone substantial changes, a fact that has negatively impacted the dental health of children. Primary prevention is the ideal method to address the current increased incidence of tooth decay. Educating kids, and their parents, about the qualities of snacks as well as the role of frequency of snacking could help to reduce…

  13. Reptile Facts.

    Science.gov (United States)

    Steinheimer, Margaret

    1993-01-01

    Describes an award-winning bulletin board for introducing a unit on reptiles. This interactive bulletin board contains fun facts and counters common misconceptions about reptiles. Twelve true-false statements are hidden behind pull-up flaps. Four pictures ask students to identify the difference between often-confused animals. (PR)

  14. Earthquake Facts

    Science.gov (United States)

    Jump to Navigation Earthquake Facts The largest recorded earthquake in the United States was a magnitude 9.2 that struck Prince William Sound, ... we know, there is no such thing as "earthquake weather" . Statistically, there is an equal distribution of ...

  15. Experimental study on penetration of dental implants into the maxillary sinus in different depths

    Directory of Open Access Journals (Sweden)

    Weijian ZHONG

    2013-12-01

    Full Text Available The exposing of dental implant into the maxillary sinus combined with membrane perforation might increase risks of implant failure and sinus complications. Objective: The purpose of this study was to investigate the effects of the dental implant penetration into the maxillary sinus cavity in different depths on osseointegration and sinus health in a dog model. Material and Methods: Sixteen titanium implants were placed in the bilateral maxillary molar areas of eight adult mongrel dogs, which were randomly divided into four groups according to the different penetrating extents of implants into the sinus cavities (group A: 0 mm; group B: 1 mm; group C: 2 mm; group D: 3 mm. The block biopsies were harvested five months after surgery and evaluated by radiographic observation and histological analysis. Results: No signs of inflammatory reactions were observed in any maxillary sinus of the eight dogs. The tips of the implants with penetrating depth of 1 mm and 2 mm were found to be fully covered with newly formed membrane and partially with new bone. The tips of the implants with penetrating depth over 3 mm were exposed in the sinus cavity and showed no membrane or bone coverage. No significant differences were found among groups regarding implant stability, bone-to-implant contact (BIC and bone area in the implant threads (BA. Conclusions: Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant osseointegration in canine.

  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; Hernández-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 (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). Results 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). Conclusions 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. Key words:Primary stability, tapered, cylindrical, conical, implant macro-design. PMID:26827067

  17. 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.

  18. Observational study of 67 wide platform implants treated with avantblast surface. Results at three year.

    Science.gov (United States)

    Barona-Dorado, Cristina; Martínez-Rodríguez, Natalia; Torres-Lear, Francisco; Martínez-González, José-Ma

    2009-04-01

    This paper shows the results of the clinical and radiographic behavior, at 3 years, of 67 wide platform implants undergoing prosthetic load. This is an observational prospective study of 67 implants in 49 patients within the range of 54-69 years of age. Screening was performed after a radiological study with panoramic and tomographic radiographs followed by the implantological treatment with prosthetic load and clinical (15 days, 1, 6, 12, 24 and 36 months) and radiological control follow-up (6, 12, 24 and 36 months). During the healing period 1 implant failed, representing a 98.5% survival. After placing the prosthesis, it was not necessary to remove any implant, therefore 66 implants remain successfully in place. The favorable results and follow-up after the prosthetic load of 66 implants (CSR of 100%) attest that wide platform implants can and should be applied after careful planning and case selection.

  19. Clinical and biologic factors related to oral implant failure: a 2-year follow-up study.

    Science.gov (United States)

    Moheng, Patrick; Feryn, Jean-Marc

    2005-09-01

    The purpose of this study is to evaluate urinary biomarkers of bone formation and resorption as predictive factors for oral implant failure, and to contribute to the knowledge of factors related to oral implant failure. A total of 93 patients between 18 and 85 years old, with an indication of oral implant, were eligible in this 2-year prospective, open, and nonrandomized study. Patients who had bone graft before implantation or presented with prosthetic difficulties (implant-to-crown ratio coating. Serum osteocalcin, and urinary pyridinoline and deoxypyridinoline were measured, together with bone density at implant location. The primary endpoint (implant failure) was the implant removal (radiographic evidence of peri-implant bone loss and/or pockets). Factors related to implant failure were analyzed using multilevel logistic regression models to consider within-patient effects. Of the 93 patients included, 61% were female, and 16% were current smokers. A total of 266 oral implants were placed and analyzed, with a mean number of 3.1 implants by patient. Eleven and 15% of bone locations scored at D1 and D4, respectively, for the Misch bone density scoring. The majority of implants (72%) were placed more than 3 months after tooth extraction, using a Frialit-2 system in 73% of cases. The mean of osteocalcin was 17.3 (+/-9.4) ng/L; those of pyridinoline and deoxypyridinoline were 33.2 (+/-15.8) and 10.2 (+/-11.9) mmol per creatinine mmol, respectively. At one-year, 95.5% (95% confidence interval 92.5-97.5) of implants have not been removed. One year later, no further implant failed. In both univariate and multivariate analysis, osteocalcin, pyridinoline, and deoxypyridinoline were not significant predictive factors of oral implant failure. In multilevel logistic regression analysis, only tobacco consumption and single-tooth replacement or removable prosthesis were independent and significant predictive factors of oral implant failure. Serum osteocalcin, and urinary

  20. Gold implant therapy of locomotory disorders in dogs - Case studies

    Directory of Open Access Journals (Sweden)

    Emilia Abrudean

    2016-06-01

    Full Text Available The case study was conducted between October and January 2015, on 7 dogs of different breeds and ages, which at clinical examination showed varying degrees of lameness. The dogs behavior and state of consciousness, their attitude in standing, decubitus and at walk and the presence of involuntary movements was assessed through inspection. Palpation was used to feel muscular tonus, local temperature and sensibility. Postural reactions were highlighted by carrying out forced positions of each limb, thus highlighting the proprioceptive sensitivity. By testing the spinal reflexes the reactions of the forelimbs and hind limbs were evaluated, seeking the state of normality, or the absence, diminution or exacerbation of these reflexes. Also, diagnostic imaging was performed consisting of simple radiographs, were performed for the cases that entered the clinic. In the case of digital X-rays, X-rays are passing through the subject being examined are filtered, then touch a plate of sensors able to convert signals generated into digital information with an image appear on the computer screen. Interpretation of results was done by assessing the degree of dysplasia, and the Norberg-Olson angle and stage. This study used digital radiography as imaging technique; the device was Rx-M EVO Fujifilm. On the basis of diagnostic imaging and computerized image, diagnosis was established for each case. The treatment protocol with gold implant was the same for all seven cases; the adopted procedure was the "Wiener" procedure, described by Kasper and Zohmann. The procedure began with establishing a set of points associated with the treatment of hip dysplasia, spondylosis, arthritis, and osteochondritis. For the therapeutic protocol to be performed correctly took the dogs were sedated. This was done with medetomidine hydrochloride (Dorbene vet, Pfizer, concentration 1 mg⁄ml, administered in a 0,1mg⁄kg body weight dose. The results were visible after a month from the

  1. A retrospective study on related factors affecting the survival rate of dental implants

    Science.gov (United States)

    Kang, Jeong-Kyung; Lee, Ki; Lee, Yong-Sang; Park, Pil-Kyoo

    2011-01-01

    PURPOSE The aim of this retrospective study is to analyze the relationship between local factors and survival rate of dental implant which had been installed and restored in Seoul Veterans Hospital dental center for past 10 years. And when the relationship is found out, it could be helpful to predict the prognosis of dental implants. MATERIALS AND METHODS A retrospective study of patients receiving root-shaped screw-type dental implants placed from January 2000 to December 2009 was conducted. 6385 implants were placed in 3755 patients. The following data were collected from the dental records and radiographs: patient's age, gender, implant type and surface, length, diameter, location of implant placement, bone quality, prosthesis type. The correlations between these data and survival rate were analyzed. Statistical analysis was performed with the use of Kaplan-Meier analysis, Chi-square test and odds ratio. RESULTS In all, 6385 implants were placed in 3755 patients (3120 male, 635 female; mean age 65 ± 10.58 years). 108 implants failed and the cumulative survival rate was 96.33%. There were significant differences in age, implant type and surface, length, location and prosthesis type (P.05). CONCLUSION Related factors such as age, implant type, length, location and prosthesis type had a significant effect on the implant survival. PMID:22259704

  2. 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...

  3. 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.

  4. Development of novel risperidone implants using blends of polycaprolactones and in vitro in vivo correlation studies.

    Science.gov (United States)

    Navitha, Aerrolla; Jogala, Satheesh; Krishnamohan, Chinnala; Aukunuru, Jithan

    2014-04-01

    The objective of this study was to develop a novel implant containing risperidone intended for long-term treatment in Schizophrenia utilizing in vitro in vivo correlation (IVIVC) studies. Different implants (F1-F8) containing an antipsychotic drug, risperidone, were prepared using a hot melt extrusion technique by taking polycaprolactones of different molecular weights (Mwt. 15000, 45000, 80000) either alone or as their blends, and PLGA (75:25). The implants contained 40% of the drug. After fabrication, the implants were characterized for various in vitro properties such as drug release and physical strength. Prior to conducting drug release studies, optimum drug release method was developed based on IVIVC studies. An optimized formulation based on drug release and physical strength at the end of fabrication was selected from the various implants fabricated. The bioactivity, reversibility, and IVIVC of optimized formulation were determined using pharmacokinetic studies in rats. Short-term stability studies were conducted with optimized formulation. Drug release depended on polymer molecular weight. Implant fabricated using 50:50 polycaprolactone 45,000 and polycaprolactone 80,000 was considered optimized implant. Optimized formulation selected released the drug for 3-months in vitro and was physically rigid. The optimized implant was able to release the drug in vivo for a period of 3 months, the implants are reversible throughout the delivery interval and, a 100% IVIVC was achieved with optimized implant, suggesting the development of 3-month drug-releasing implant for risperidone. The optimized implant was stable for 6 months at room temperature (25°C) and 45°C. A novel implant for risperidone was successfully prepared and evaluated.

  5. Development of novel risperidone implants using blends of polycaprolactones and in vitro in vivo correlation studies

    Directory of Open Access Journals (Sweden)

    Aerrolla Navitha

    2014-01-01

    Full Text Available The objective of this study was to develop a novel implant containing risperidone intended for long-term treatment in Schizophrenia utilizing in vitro in vivo correlation (IVIVC studies. Different implants (F1-F8 containing an antipsychotic drug, risperidone, were prepared using a hot melt extrusion technique by taking polycaprolactones of different molecular weights (Mwt. 15000, 45000, 80000 either alone or as their blends, and PLGA (75:25. The implants contained 40% of the drug. After fabrication, the implants were characterized for various in vitro properties such as drug release and physical strength. Prior to conducting drug release studies, optimum drug release method was developed based on IVIVC studies. An optimized formulation based on drug release and physical strength at the end of fabrication was selected from the various implants fabricated. The bioactivity, reversibility, and IVIVC of optimized formulation were determined using pharmacokinetic studies in rats. Short-term stability studies were conducted with optimized formulation. Drug release depended on polymer molecular weight. Implant fabricated using 50:50 polycaprolactone 45,000 and polycaprolactone 80,000 was considered optimized implant. Optimized formulation selected released the drug for 3-months in vitro and was physically rigid. The optimized implant was able to release the drug in vivo for a period of 3 months, the implants are reversible throughout the delivery interval and, a 100% IVIVC was achieved with optimized implant, suggesting the development of 3-month drug-releasing implant for risperidone. The optimized implant was stable for 6 months at room temperature (25°C and 45°C. A novel implant for risperidone was successfully prepared and evaluated.

  6. Implant stability during initiation and resolution of experimental periimplantitis: an experimental study in the dog.

    Science.gov (United States)

    Sennerby, Lars; Persson, Leif G; Berglundh, Tord; Wennerberg, Ann; Lindhe, Jan

    2005-01-01

    Histologic studies have demonstrated the possibility to reestablish direct bone-implant contacts after ligature-induced periimplantitis. The influence of the reosseointegration on the stability of implants is not known. The aim of the present investigation was to study bone tissue and associated implant stability alterations that occurred during induction and resolution of periimplantitis using resonance frequency analysis (RFA), radiography, and histology. Three implants with smooth (turned) or roughened (SLA) surfaces were placed in each side of the edentulous mandible of four dogs. Experimental periimplantitis was induced for 3 months. Five weeks later, the animals were treated with antibiotics and surgical therapy and were followed for another 6 months. Periapical radiographs and RFA were used to evaluate marginal bone levels and implant stability throughout the study period. After termination, the tissue-implant interface was evaluated by light microscopy in ground sections. There was a linear relationship between radiographic and RFA findings because continuous loss of marginal bone and a decrease in implant stability were observed for both implant surfaces during the periimplantitis period. Antibiotic treatment and surgical therapy resulted in some reosseointegration, which was more marked for the SLA surface. The resonance frequency values corresponded well to the histometric measurements because reosseointegration resulted in an increase in implant stability. The findings from the present study indicate a linear relationship between marginal bone level and resonance frequency value. It is suggested that the RFA technique is sensitive and may be used to detect even a minor change in the level of bone-implant contact.

  7. 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

  8. Bacterial Colonization of the Implant-Abutment Interface (IAI) of Dental Implants with a Sloped Marginal Design: An in-vitro Study.

    Science.gov (United States)

    Koutouzis, Theofilos; Gadalla, Hana; Lundgren, Tord

    2016-02-01

    The aim of this study is to utilize an in vitro dynamic loading model to assess the potential risk of bacterial invasion into the Implant Abutment Interface (IAI) microgap of dental implants with sloped marginal design. Forty implants were divided into two groups (n = 20 per group) based on implant marginal design. Group 1 was comprised of implants with Morse-taper connection and conventional marginal design that connected to titanium abutments. Group 2 was comprised of implants with Morse-taper connection and sloped marginal design that connected to titanium abutments. The specimens were immersed in a bacterial solution of E. coli and loaded with 500,000 cycles of 160N using a chewing simulator. Following disconnection of fixtures and abutments, microbial samples were taken from the threaded portion of the abutment, plated and cultured under appropriate conditions. Ten out of twenty implants of Group 1 and eight out of twenty implants of Group 2 had IAI microgaps colonized by E. Coli. There was not a statistically significant difference in the mean number of E. Coli CFU detected between implants of Group 1 (mean 19.2, SD 23.6) and Group 2 (mean 12.5, SD18.9) (p > .05). The present study demonstrated that implants with a sloped marginal design exhibited similar risk for bacterial invasion into the IAI microgap under in vitro dynamic loading conditions compared to implants with conventional marginal design. © 2015 Wiley Periodicals, Inc.

  9. Positron annihilation Doppler broadening study of Xe-implanted aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Yu, R.S., E-mail: yursh@ihep.ac.cn [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Maekawa, M.; Kawasuso, A. [Japan Atomic Energy Agency, Advanced Science Research Center, Watanuki 1233, Takasaki, Gunma 370-1292 (Japan); Wang, B.Y.; Wei, L. [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China)

    2013-10-01

    Positron annihilation Doppler broadening measurements were conducted to characterize information of defects in 380 keV Xe{sup +}-implanted aluminum upon thermal annealing at temperatures ranging from 100 to 600 °C. The results suggest a broad distribution in the depth of vacancy-type defects in all the as-implanted samples. Meanwhile, with an increase in implantation dose the defect-rich region shifts toward the sample surface. It was found that increasing the annealing temperature triggers surface-directed migration and coalescence of vacancy and Xe{sub n}V{sub m} clusters in samples with implantation doses of 1E15 and 1E16 Xe{sup +}cm{sup −2}. In the sample implanted with a high dose of 1E17 Xe{sup +}cm{sup −2}, positron annihilation revealed a decomposition and even elimination of such defects under post-implantation annealing treatment.

  10. The fact and the fiction: A prospective study of internet forum discussions on vaginal breech birth.

    Science.gov (United States)

    Petrovska, Karolina; Sheehan, Athena; Homer, Caroline S E

    2017-04-01

    Women with a breech baby late in pregnancy may use the internet to gather information to assist in decision-making for birth. The aim of this study was to examine how women use English language internet discussion forums to find out information about vaginal breech birth and to increase understanding of how vaginal breech birth is perceived among women. A descriptive qualitative study of internet discussion forums was undertaken. Google alerts were created with the search terms "breech birth" and "breech". Alerts were collected for a one-year period (January 2013-December 2013). The content of forum discussions was analysed using thematic analysis. A total of 50 forum discussions containing 382 comments were collected. Themes that arose from the data were: Testing the waters-which way should I go?; Losing hope for the chance of a normal birth; Seeking support for options-who will listen to me?; Considering vaginal breech birth-a risky choice?; Staying on the 'safe side'-caesarean section as a guarantee; Exploring the positive potential for vaginal breech birth. Women search online for information about vaginal breech birth in an attempt to come to a place in their decision-making where they feel comfortable with their birth plan. This study highlights the need for clinicians to provide comprehensive, unbiased information on the risks and benefits of all options for breech birth to facilitate informed decision-making for the woman. This will contribute to improving the woman's confidence in distinguishing between "the fact and the fiction" of breech birth discussions online. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  11. Initial Stability Study of Calcium Phosphate Coated Dental Implants

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Thin film of biodegradable calcium phosphate coated on threaded commercially pure titanium( cp- Ti) dental implants has been investigated as one of alternatives to eliminate the problem of the long-term instability of plasma sprayed HA coated implants. In order to compare in-vivo hone-to-implant response behavior among as-machined, HA coated and CMP coated groups, each group was implanted into New Zealand white mature male rabbits for 2 and 6 weeks, and then in- vivo biological behavior was examined in terms of H&E staining. Initial stability and removable torques of implants were compared among three groups. Measured removable torque of CMP coated specimen at 6 wceks after implantation was significantly higher than that of non-coated group, but slightly lower than that of HA coated group, without any inflammatory response at the surrounding of the implants. The initial stability (ISQ value; implant stability quotient ) of CMP coated specimen at 2 weeks after implantation was slightly lower than that of HA coated group and significantly higher than that of non-coated group. However, after 6 weeks, ISQ value of CMP coated group was slightly higher than that of HA coated group and significantly higher than that of non-coated group.

  12. 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.

  13. Development of novel risperidone implants using blends of polycaprolactones and in vitro in vivo correlation studies

    OpenAIRE

    2014-01-01

    The objective of this study was to develop a novel implant containing risperidone intended for long-term treatment in Schizophrenia utilizing in vitro in vivo correlation (IVIVC) studies. Different implants (F1-F8) containing an antipsychotic drug, risperidone, were prepared using a hot melt extrusion technique by taking polycaprolactones of different molecular weights (Mwt. 15000, 45000, 80000) either alone or as their blends, and PLGA (75:25). The implants contained 40% of the drug. After f...

  14. Survival of immediately versus delayed loaded short implants: a prospective case series study

    OpenAIRE

    Alvira González, Joaquín; Díaz Campos, Erick; Sánchez Garcés, María Angeles; Gay Escoda, Cosme

    2015-01-01

    Background To assess and compare survival rates of immediately and delayed loaded short implants (7 mm) in free ends of a partially edentulous jaw with moderate-severe alveolar bone resorption. Material and Methods 24 patients with atrophic edentulous free-ends were included in this prospective study. Four study groups were monitored monthly and their behavior was evaluated: bridges supported only by short implants and mixed short and long implant bridge groups, both with immediate and delaye...

  15. 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

  16. The effects of high-fat diet on implant osseointegration: an experimental study

    Science.gov (United States)

    2016-01-01

    Objectives In this study, we investigated whether a high-fat diet (HFD) affected the bone implant connection (BIC) in peri-implant bone. Materials and Methods Four male rabbits were used in this study. Dental implant surgery was introduced into each tibia, and four implants were integrated into each animal. In both the normal diet (ND) group (n=2) and HFD group (n=2), 8 implants were integrated, for a total of 16 integrated implants. The animals continued with their respective diets for 12 weeks post-surgery. Afterward, the rabbits were sacrificed, and the BIC was assessed histomorphometrically. Results Histologic and histomorphometric analyses demonstrated that BIC was not impaired in the HFD group compared to the ND group. Conclusion Within the limitations of this study, we found that HFD did not decrease the BIC in rabbit tibias. PMID:27595085

  17. Fabrication and characterization of porous hydroxyapatite ocular implant followed by an in vivo study in dogs

    Indian Academy of Sciences (India)

    B Kundu; M K Sinha; M K Mitra; D Basu

    2004-04-01

    Porous hydroxyapatite ocular implant was fabricated by a novel and simple method using hydroxyapatite powder synthesized in the laboratory. The porosity and pore size of the implant were controlled to make it light in weight as well as suitable for rapid vascularization after implantation. The implant was characterized by X-ray diffraction studies, infrared spectra and chemical analysis for phase purity and chemical composition. The pore morphology and pore size distribution of the samples were investigated by scanning electron microscope (SEM). Thereafter, efficacy of the implant was examined by in vivo study in dogs. Clinical, haematological and radiological studies indicated the suitability of the implant for replacement of the lost eye of human patients.

  18. Osteoblast integration of dental implant materials after challenge by sub-gingival pathogens : a co-culture study in vitro

    NARCIS (Netherlands)

    Zhao, Bingran; van der Mei, Henny C.; Rustema-Abbing, Minie; Busscher, Henk J.; Ren, Yijin

    2015-01-01

    Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration

  19. 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.

  20. Osteoblast integration of dental implant materials after challenge by sub-gingival pathogens : a co-culture study in vitro

    NARCIS (Netherlands)

    Zhao, Bingran; van der Mei, Henny C; Rustema-Abbing, Minie; Busscher, Henk J; Ren, Yijin

    2015-01-01

    Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration

  1. 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.

  2. Changes in biting forces with implant-supported overdenture in the lower jaw: A comparison between conventional and mini implants in a pilot study.

    Science.gov (United States)

    Hasan, I; Madarlis, C; Keilig, L; Dirk, C; Weber, A; Bourauel, C; Heinemann, F

    2016-11-01

    The biting ability of patients improves noticeably after receiving implant-supported overdentures in comparison to conventional complete dentures. However, the change of biting with such treatment concepts has been quantitatively investigated in only a limited number of studies. The aim of the present study has been to measure the biting forces of edentulous patients with complete dentures and after receiving implant-supported overdentures. A total of 26 edentulous patients were included. Ten patients received two to four conventional implants (control group, Ø3.3-3.7mm, L11-13mm) and 16 patients received four to five mini implants (study group, Ø1.8-2.4mm, L13-15mm) inserted in the mandibular interforaminal region. All patients received a lower overdenture with ball/rubber ring attachments and a complete denture for the maxilla. The biting forces were measured using Prescale pressure sheets type low before the insertion of implants and after receiving implant-supported overdenture. The measured sheets were later scanned and analysed using FPD-8010E software. The range of biting forces before the insertion of implants was 80N-122N for the control group and 66-88N for the study group. After the insertion of implants, the range of biting forces increased to 167N-235N for the control group and to 81N-138N for the study group. However, the increase in biting forces after the insertion of implants was not significant for either group. No significant difference was obtained between the two implant systems. The biting forces improved after insertion of implants regardless of which implant system was used. However, the degree of improvement is noticeably related to the original bone quality of the mandible at the insertion regions of implants.

  3. Thermal-mechanical study of functionally graded dental implants with the finite element method.

    Science.gov (United States)

    Wang, F; Lee, H P; Lu, C

    2007-01-01

    This article investigates the thermal-mechanical performance of hydroxyapatite/titanium (HA/Ti) functionally graded (FG) dental implants with the three-dimensional finite element method. The stresses induced by occlusal force for the present HA/Ti FG implant are calculated to compare with the corresponding stresses for the titanium dental implant. Thermal-mechanical effect of temperature variation due to daily oral activity is also studied. The HA/Ti FG dental implant performance is evaluated against the maximum von Mises stress, which is the general performance indicator, the first principal/tensile stress for mechanical failure of implant-bone-bond and the third principal/compressive stress for bone absorption. Simulation results indicate that under the influence of occlusal force only, the FG implants with different HA fraction along the implant length perform almost equally well, while the titanium implant sustains much higher von Mises stress. However, when thermal stress is also considered, the FG implant having HA fraction exponential index of m = 2 with temperature decrease of 20 degrees C yields the highest first principal and von Mises stresses among all the FG and titanium implants.

  4. Influence of Implant Surface Topography on Primary Stability in a Standardized Osteoporosis Rabbit Model Study

    Directory of Open Access Journals (Sweden)

    Hiroshi Oue

    2015-03-01

    Full Text Available Evaluating primary stability is important to predict the prognosis of dental implant treatment. Primary stability is decreased in a low bone density site such as osteoporosis. However, it is difficult to apply in small animal and the effect of the different implant surface topography for the primary stability at low bone density site has not yet fully been investigated. The purpose of the present study was to evaluate the influence of implant surface topography on primary stability in a standardized osteoporosis animal model. Six rabbits underwent ovariectomy and administrated glucocorticoid to induce an osteoporosis model. Sham-operations were performed in additional six rabbits. Implants with machined or oxidized-surfaces were inserted into the femur epiphyses and insertion torque (IT and implant stability quotient (ISQ were measured. In sham model, the IT and ISQ did not differ significantly between the both implant. However, the IT value of oxidized-surface implant was significantly higher than that of the machined implant in the osteoporosis model. Meanwhile, ISQ did not significantly differ between the machined and oxidized-surfaced implants. In conclusion, the IT of implants is higher with rough than with smooth surfaces but that there are no differences in ISQ value between different surfaces in a standardized osteoporosis bone reduced rabbit model.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K

    2000-07-01

    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

  6. Diabetes mellitus and dental implants: a clinical study.

    Science.gov (United States)

    Abdulwassie, Hassan; Dhanrajani, P J

    2002-01-01

    Diabetes mellitus is no longer considered to be a contraindication for implant-supported prostheses, provided that the patient's blood sugar is under control, and that there is motivation for oral hygiene procedures. This paper presents the experiences of treating diabetic patients using implants with good success rates.

  7. [Subperiosteal mandibular implant. Clinical cases and microscopic study].

    Science.gov (United States)

    Rosson, J O

    1990-04-01

    Subperiosteal surgical Vitallium implants have been set in the mandible of patients with loss of height of the osseous ridge and difficulty in the use of prostheses obtaining very good clinical and radiographical results. The optic microscopy showed a great tendency of adhesion of the gingiva's junctional epithelium to the implant.

  8. Implant-supported single-tooth restorations: a 5-year prospective study.

    Science.gov (United States)

    Wennström, Jan L; Ekestubbe, Annika; Gröndahl, Kerstin; Karlsson, Stig; Lindhe, Jan

    2005-06-01

    Comparatively few studies are available reporting at least 5 years of follow-up data of implant-supported single-tooth replacements. To evaluate prospectively the 5-year outcome of implant-supported single-tooth prosthetic restorations. Forty subjects (mean age 41 years), 23 males and 17 females, who required single-tooth prosthetic replacement for a missing tooth were recruited. A total of 45 self-tapping implants (Astra Tech ST-implants)--40 in the maxilla and five in the mandible--were installed in a two-stage procedure. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographic examinations were performed at the completion of the prosthetic treatment and once a year during a 5-year follow-up period. The analysis of peri-implant bone level alteration was performed on subject and implant levels and by the use of analysis of variance and binary logistic regression. Three patients were lost during the 5 years of follow-up. One implant was lost after 2.5 years in function and another four implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 2.6% (subject level) and 2.3% (implant level). The mean loss of marginal bone at the implants during the first year in function was 0.06 mm (SD 0.67) on the subject level and 0.02 mm (0.65) on the implant level. During the subsequent 4 years the annual change in peri-implant bone level amounted to -0.02 mm (0.22) on both subject and implant levels. Thus, the mean total bone level change over the 5-year interval was -0.14 mm (1.04) on subject level and -0.11 mm (1.00) on the implant level of analysis (p>0.05). The frequency of implants with a 5-year bone loss of > or =1 mm was 13%. Approximately 50% of the implants demonstrated no bone loss. The present clinical trial on single-tooth replacements with the Astra Tech implant system demonstrated that the bone loss during the first year of function as well as annually thereafter was

  9. Microarray expression in peri-implant tissue next to different titanium implant surfaces predicts clinical outcomes: a split-mouth study.

    Science.gov (United States)

    Menini, M; Dellepiane, E; Baldi, D; Longobardi, M G; Pera, P; Izzotti, A

    2017-09-01

    This split-mouth study evaluated miRNA expression of tissues around implants with different surface treatments. Each patient of the sample (five men and five women) received two implants (one control and one test) into an edentulous quadrant to support fixed partial dentures. The control implants (Osseotite) had a dual acid-etched (DAE) surface in the apical portion and a machined coronal part, test implants (Full Osseotite, FOSS) were completely DAE. Machined healing abutments were placed on control implants and DAE abutments on test ones. All implants were assigned codes for blinding. Standardized periapical radiographs were taken at baseline, 2 and 6 months, and 1 year after surgery. Plaque index (PI), bleeding on probing (BOP), and probing depth (PD) were recorded at 3 and 6 weeks, and 2, 3, 6, and 12 months post-implant placement. After 3 months, a mini-invasive sample of soft tissue was collected from seven patients (four women and three men) for miRNA microarray analysis. Control implants showed greater bone resorption (BR) and lower PI: this was not statistically significant. No statistically significant differences in BOP and PD appeared. miRNA modulated by implant surfaces as well as by other clinical conditions has been identified. miRNA microarray analysis revealed that: (i) implant sites with low PI and absence of BOP had a miRNA expression profile similar to those with plaque and absence of BOP; sites with high PI and high BOP had a different profile. (ii) Implant sites with BOP presented similar profiles independently from implant surface. (iii) Implant sites with high PI and normal BR differed from others for miRNA expression profile. (iv) Implant sites with normal BR despite high BOP differed from others. This profile resembled that of FOSS implants. (v) Implant surface affected BR; groups having similar BR clusterized differently according to the implant type. DAE surfaces induced lower BR and more plaque accumulation: This did not affect the

  10. 7-Be Implantation in Plastics for Prosthesis Wear Studies

    Science.gov (United States)

    Greife, Uwe; Erikson, L.; Patel, N.; Wimmer, M.; Dwiwedi, Y.; Laurent, M.; Chipps, K.; Blackmon, J.; Kozub, R.; Bardayan, D.; Gross, C.; Stracener, D.; Smith, M.; Nesaraya, C.; Rehm, E.; Ahmed, I.; Greene, J.

    2010-11-01

    The current generation of highly cross linked ultrahigh molecular weight polyethylenes (PE) for hip and knee joint replacement have achieved such low in vitro wear rates that efforts have been underway to develop more sensitive methods to measure polyethylene wear. The most widely used technique, the gravimetric method, suffers from the notable disadvantage that mass gain by fluid absorption can considerably exceed mass loss by wear, making the wear measurement inaccurate, sometimes even leading to negative ``wear'' values. The purpose of this experiment was to investigate the use of a radioactive tracer, beryllium-7 (7-Be), to circumvent the problem of fluid absorption and thereby achieve a much more sensitive and accurate wear measurement. This proof of principle study demonstrated the general feasibility of 7-Be implantation (performed at the Holifield Radioactive Ion Beam Facility of Oak Ridge National Laboratory) for PE wear analysis.

  11. 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.

  12. Study of defects in implanted silica glass by depth profiling Positron Annihilation Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brusa, R.S., E-mail: brusa@science.unitn.i [CNISM, Dipartimento di Fisica, Universita di Trento, Via Sommarive 14, I-38050 Povo, Trento (Italy); Mariazzi, S. [CNISM, Dipartimento di Fisica, Universita di Trento, Via Sommarive 14, I-38050 Povo, Trento (Italy); Ravelli, L. [CNISM, Dipartimento di Fisica, Universita di Trento, Via Sommarive 14, I-38050 Povo, Trento (Italy); Institut fuer Angewandte Physik und Messtechnik, Universitaet der Bunderswehr Muenchen, 85577 Neubiberg (Germany); Mazzoldi, P.; Mattei, G. [CNISM, Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy); Egger, W. [Institut fuer Angewandte Physik und Messtechnik, Universitaet der Bunderswehr Muenchen, 85577 Neubiberg (Germany); Hugenschmidt, C.; Loewe, B.; Pikart, P. [Physik Department E21 and FRMII, Technische Universitaet Muenchen, 85747 Garching (Germany); Macchi, C.; Somoza, A. [IFIMAT, UNCentro and CICPBA, Pinto 399, B7000GHG Tandil (Argentina)

    2010-10-01

    Positron Annihilation Spectroscopy (PAS) performed with continuous and pulsed positron beams allows to characterize the size of the intrinsic nano-voids in silica glass, their in depth modification after ion implantation and their decoration by implanted ions. Three complementary PAS techniques, lifetime spectroscopy (LS), Doppler broadening spectroscopy (DBS) and coincidence Doppler broadening spectroscopy (CDBS) will be illustrated by presenting, as a case study, measurements obtained on virgin and gold implanted silica glass.

  13. No effect of hydroxyapatite particles in phagocytosable sizes on implant fixation: an experimental study in dogs

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Bendix, K

    2005-01-01

    The influence of wear debris on bone healing around orthopedic implants is debated. Hydroxyapatite (HA) particles and polyethylene (PE) particles have been shown to have a negative effect on osteoblast cultures in vitro. The present study investigated the in vivo effects of HA and PE particles on....... HA particles were also integrated in newly formed bone. We found no negative effect of the particulate material on mechanical fixation of the implants or on bone formation around the implants....

  14. A CLINICAL STUDY ON THE INCIDENCE AND MANAGEMENT OF BIOLOGICAL COMPLICATIONS IN IMPLANT THERAPY

    Directory of Open Access Journals (Sweden)

    Nicolae VASILE

    2015-09-01

    Full Text Available The scope of the study was to evidence the methods recommended for avoiding, managing and implementing an efficient treatment capable of reducing the biological complications accompanying implant therapies. Materials and method. The study evaluates the patients with prosthesis charged implants - or during their osseointegration period - inserted in the Clinic of The Emergency Military Hospital of Sibiu, over a 5 year period (2009-2014. Retrospective investigation was based on the evaluation of the treatment files and on the imagistic and clinical analyses of the 125 patients to whom 385 implants had been inserted. Results and discussion. The study demonstrates that, when implants are the support of an overdenture, surrounded by either limited keratinized gingiva or mobile tissues, the presence of the bacterial plaque is considerable, the peri-implant pocket exceeds 5 mm, and sensitivity and bleeding are produced on contact with the probe. In susceptible patients, or in those with pathological periodontal antecedents, the re-infection potential has been always higher. The clinical study confirms that, invariably, peri-implantitis is associated with the existence of the bacterial plaque and also with the presence of a peri-implant pocket exceeding 4 mm (8.9%, with partial exposure of the covering screw (4.5% and fixed restaurations without self-cleaning spaces (2%. Conclusions. Out of the post-surgery biological complications, peri-implantitis is the most frequent one, causing a – sometimes total – loss of the alveolar bone around the osseointegrated implant.

  15. [Bilateral cochlear implantation].

    Science.gov (United States)

    Kronenberg, Jona; Migirov, Lela; Taitelbaum-Swead, Rikey; Hildesheimer, Minka

    2010-06-01

    Cochlear implant surgery became the standard of care in hearing rehabilitation of patients with severe to profound sensorineural hearing loss. This procedure may alter the lives of children and adults enabling them to integrate with the hearing population. In the past, implantation was performed only in one ear, despite the fact that binaural hearing is superior to unilateral, especially in noisy conditions. Cochlear implantation may be performed sequentially or simultaneously. The "sensitive period" of time between hearing loss and implantation and between the two implantations, when performed sequentially, significantly influences the results. Shorter time spans between implantations improve the hearing results after implantation. Hearing success after implantation is highly dependent on the rehabilitation process which includes mapping, implant adjustments and hearing training. Bilateral cochlear implantation in children is recommended as the proposed procedure in spite of the additional financial burden.

  16. Characterization and simulation studies on high tilt ion implantation for precision halo implant applications

    Energy Technology Data Exchange (ETDEWEB)

    Guo, B.N. [Varian Semiconductor Equipment Associates, Inc., 35 Dory Road, Gloucester, MA 01930 (United States)]. E-mail: baonian.guo@vsea.com; Zhao, Z.Y. [Spansion LLC, 5204 E. Ben White Blvd., Austin, TX 78741 (United States); Falk, S. [Varian Semiconductor Equipment Associates, Inc., 35 Dory Road, Gloucester, MA 01930 (United States); Liu, J. [Varian Semiconductor Equipment Associates, Inc., 35 Dory Road, Gloucester, MA 01930 (United States); Shim, K.H. [Varian Semiconductor Equipment Associates, Inc., 35 Dory Road, Gloucester, MA 01930 (United States); Jeong, U. [Varian Semiconductor Equipment Associates, Inc., 35 Dory Road, Gloucester, MA 01930 (United States); Mehta, S. [Varian Semiconductor Equipment Associates, Inc., 35 Dory Road, Gloucester, MA 01930 (United States)

    2007-08-15

    Precision dopant placement at high tilt angles for halo applications is required in the fabrication of advanced devices to achieve better transistor characteristics, such as suppression of short channel effects, V {sub t} control and drive current. However, monitoring high tilt implants is not popular in semiconductor fabs, even though most have started monitoring zero-tilt implants in the recent couple of years. In this paper, the authors explore the possibilities of using high tilt angles with higher Miller Index channels. As an example, axial channeling along the <1 1 2> direction is used to evaluate the angle control performance of the VIISta 810EHP medium current ion implanter. Crystal-TRIM (a Monte Carlo simulation code) calculations are compared with experimental SIMS (Secondary Ion Mass Spectrometry) profiles. In addition, the effects of wafer orientation on the platen and wafer mis-cut on the dopant profiles are discussed. Metrology characterization, such as ThermaWave{sup TM} and SIMS, of the <1 1 2> ion channeling is presented.

  17. 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

    INTRODUCTION: A major determinant of successful osseointegration of endosseous implants is the surface of the implant, which influences the cellular response of the surrounding tissues. A new strategy to improve osseointegration and bone healing is biochemical stimulation by surface nanocoatings...... 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...

  18. 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.

  19. 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.

  20. Stylized Facts Generated Through Cellular Automata Models. Case of Study: The Game of Life

    CERN Document Server

    Coronel-Brizio, H F; Rodriguez-Achach, M E; Stevens-Ramirez, G A

    2007-01-01

    In the present work, a geometrical method to generate a two dimensional random walk by means of a bidimensional Cellular Automaton is presented. We illustrate it by means of Conway's Game of Life with periodical borders, with a large lattice of 3000 x 3000 cells. The obtained random walk is of character anomalous, and its projection to a one dimensional random walk is analyzed, showing that it presents some statistical properties similar to the so-called stylized facts observed in financial time series. We consider that the procedure presented here is important not only because of its simplicity, but also because it could help us to understand and shed light on the stylized facts formation mechanism.

  1. Agri-technologies and travelling facts: case study of extension education in Tamil Nadu, India

    OpenAIRE

    2008-01-01

    This paper is motivated by two broad questions: how is technology transferred from academia to non-academic domains, and how well do facts within these technologies travel? These questions are explored in the context of a particular extension education program in Tamil Nadu, south India. The paper explores the extent to which fertigation technologies (drip irrigation) and other farm and postharvest technologies travelled from the Tamil Nadu Agricultural University to the farming community in ...

  2. Peri-implant biomechanical responses to standard, short-wide, and mini implants supporting single crowns under axial and off-axial loading (an in vitro study).

    Science.gov (United States)

    Kheiralla, Lamia Sayed; Younis, Jihan Farouk

    2014-02-01

    This study compared the biomechanical responses of 3 single crowns supported by 3 different implants under axial and off-axial loading. A standard implant (3.75 mm diameter, 13 mm length), a mini implant (3 mm diameter, 13 mm length), and a short-wide implant (5.7 mm diameter, 8 mm length) were embedded in epoxy resin by the aid of a surveyor to ensure their parallelism. Each implant supported a full metal crown made of Ni-Cr alloy with standardized dimensions. Strain gauges and finite element analysis (FEA) were used to measure the strain induced under axial and off-axial functional loads of 300 N. Results showed that mini implants recorded the highest microstrains, under both axial and off-axial loading. All implants showed a considerable increase in strain values under off-axial loading. Standard and short-wide implants proved to be preferable in supporting crowns, as the standard implant showed the lowest strains under axial and off-axial loading using FEA simulation, while the short-wide implant showed the lowest strains under nonaxial loading using strain gauge analysis.

  3. Speech and language skills of Maltese children with bilateral cochlear implants : three case studies

    OpenAIRE

    2014-01-01

    The purpose of this study was to document the speech and language skills of three Maltese children with bilateral cochlear implants. One child was simultaneously implanted and had a hearing age (HA) of 2;10 years at the time of testing, another was sequentially implanted and had a HA of 3;06 years, while the third child was sequentially implanted and had a HA of 5;03 years. Maltese standardised speech and language assessments were used to gather information on the childre...

  4. Patient perceptions of implantable cardioverter-defibrillator deactivation discussions: A qualitative study

    Directory of Open Access Journals (Sweden)

    Jane MacIver

    2016-04-01

    Full Text Available Background: There is a class I recommendation for implantable cardioverter-defibrillator deactivation discussions to occur between physicians and heart failure patients. Few studies have reported the patient’s perspective on the timing of implantable cardioverter-defibrillator deactivation discussions. Aim: To determine patient awareness, preferences and timing of implantable cardioverter-defibrillator deactivation discussions. Design: Grounded theory was used to collect and analyze interview data from 25 heart failure patients with an implantable cardioverter-defibrillator. Setting and participants: Patients with an implantable cardioverter-defibrillator, from the Heart Function Clinic at University Health Network (Toronto, Canada. Results: The sample (n = 25 was predominately male (76% with an average age of 62 years. Patients identified three stages where they felt implantable cardioverter-defibrillator deactivation should be discussed: (1 prior to implantation, (2 with any significant deterioration but while they were of sound mind to engage in and communicate their preferences and (3 at end of life, where patients wished further review of their previously established preferences and decisions about implantable cardioverter-defibrillator deactivation. Most patients (n = 17, 68% said they would consider deactivation, six (24% were undecided and two (8% were adamant they would never turn it off. Conclusion: The patient preferences identified in this study support the need to include information on implantable cardioverter-defibrillator deactivation at implant, with change in clinical status and within broader discussions about end-of-life treatment preferences. Using this process to help patients determine and communicate their implantable cardioverter-defibrillator deactivation preferences may reduce the number of patients experiencing distressing implantable cardioverter-defibrillator shocks at end of life.

  5. 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

  6. 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...... measurements. Preoperatively, implants from the same batches were examined topographically with a TopScan 3D system. The TiO2-blasted implants demonstrated significantly higher removal torque values than the machined implants, and they also had a significantly more irregular surface. Furthermore, significantly...

  7. 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.

  8. A 5-year retrospective study on Replace Select Tapered dental implants.

    Science.gov (United States)

    Pettersson, Pelle; Sennerby, Lars

    2015-04-01

    Long-term data regarding survival and crestal bone loss for Replace Select Tapered implants (Nobel Biocare AB, Gothenburg, Sweden) are lacking. The study aims to present the 5-year outcomes from a retrospective analysis of Replace Select Tapered implants placed and restored in consecutive patients. A total of 88 consecutive patients (32 male, 56 female, mean age 65 ± 12 years) treated by one clinician (PP) were clinically and radiographically evaluated during at least 5 years of function. A total of 271 dental implants (Replace Select Tapered, Nobel Biocare AB) with an oxidized surface (TiUnite, Nobel Biocare AB) had been placed in both jaws (228 in the maxilla, 43 in the mandible). The majority of implants were placed in healed sites (n = 244), while 27 implants were immediately placed in extraction sockets. The majority of implants (n = 262) healed for 3 to 4 months prior to loading, and nine implants were immediately loaded. A total of 121 implant-supported restorations were delivered; 42 single tooth replacements, 61 fixed partial bridges, 14 fixed full bridges, and 4 fixed partial implant-tooth connected bridges. The marginal bone level was measured in intraoral radiographs taken after surgery (baseline), and after 1, 2, 3, 4, and 5 years. Fifty-one patients with 160 implants were followed throughout the study. One implant failed at healing abutment connection 4 months after insertion, resulting in a cumulative survival rate of 99.6%. The average crestal bone loss was 0.9 ± 1.6 mm after 1 year and 0.1 mm ± 2.4 after 5 years. There were 14.8% of measured implants that showed more than 2 mm and 5.2% more than 3 mm bone loss after 5 years, with no progression since the 1-year examination. One patient (2.0%) treated with six implants presented with significant crestal bone loss and recurrent peri-implant purulent infections at all implants. The present retrospective 5-year study showed high survival rate and steady crestal bone

  9. Strains around distally inclined implants retaining mandibular overdentures with Locator attachments: an in vitro study

    Science.gov (United States)

    Setta, Fathi Abo; Khirallah, Ahmed Samir

    2016-01-01

    PURPOSE The aim of the present study was to evaluate, by means of strain gauge analysis, the effect of different implant angulations on strains around two implants retaining mandibular overdenture with Locator attachments. MATERIALS AND METHODS Four duplicate mandibular acrylic models were constructed. Two implants were inserted in the canine regions using the following degrees of distal inclinations: group I (control); 0°, group II; 10°, group III; 20°, and group IV; 30°. Locator pink attachments were used to connect the overdenture to the implants and Locator red (designed for severely angled implants) was used for group IV (group IVred). For each group, two linear strain gauges were attached at the mesial and distal surfaces of the acrylic resin around each implant. Peri-implant strain was measured on loading and non-loading sides during bilateral and unilateral loading. RESULTS For all groups, the mesial surfaces of the implants at loading and non-loading sides experienced compressive (negative) strains, while the distal implant surfaces showed tensile (positive) strains. Group IV showed the highest strain, followed by group III, group II. Both group I and group IVred showed the lowest strain. The strain gauges at the mesial surface of the loading side recorded the highest strain, and the distal surface at non-loading side showed the lowest strain. Unilateral loading recorded significantly higher strain than bilateral loading. CONCLUSION Peri-implant strains around two implants used to retain mandibular overdentures with Locator attachments increase as distal implant inclination increases, except when red nylon inserts were used. PMID:27141255

  10. Stress distribution in implant retained finger prosthesis: a finite element study.

    Science.gov (United States)

    Amornvit, Pokpong; Rokaya, Dinesh; Keawcharoen, Konrawee; Thongpulsawasdi, Nimit

    2013-12-01

    Finger amputation may result from congenital cause, trauma, infection and tumours. The finger amputation may be rehabilitated with dental implant-retained finger prosthesis. The success of implant-retained finger prosthesis is determined by the implant loading. The type of the force is a determining factor in implant loading. To evaluate stress distributions in finger bone when the loading force is applied along the long axis of the implant using finite element analysis. The finite element models were created. The finger bone model containing cortical bone and cancellous bone was constructed by using radiograph. Astra Tech Osseo Speed bone level implant of 4.5 mm diameter and 14 mm length was selected. The force was applied to the top of the abutment along the long axis of the implant. Finite element analysis indicated that the maximum stress was located at the head of abutment screw. The minimum stress was located in the apical third of the implant fixture. The weakest point was calculated by safety factor which is located in the spongy bone at apical third of the fixtures. Finally, 4.9 times yield stress of spongy bone was needed for the deformation of the spongy bone. Finite element study showed that when the force was applied along the long axis of the implant, the maximum stress was located around the neck of the implant and the cortex bone received more stress than cancellous bone. So, to achieve long term success, the designers of implant systems must confront biomaterial and biomechanical problems including in vivo forces on implants, load transmission to the interface and interfacial tissue response.

  11. A Quasi-Experimental Study Investigating the Effect of Scent on Students' Memory of Multiplication Facts and Math Anxiety

    Science.gov (United States)

    Leap, Evelyn M.

    2013-01-01

    This quasi-experimental study was conducted with two fifth grade classrooms to investigate the effect of scent on students' acquisition and retention of multiplication facts and math anxiety. Forty participants received daily instruction for nine weeks, using a strategy-rich multiplication program called Factivation. Students in the Double Smencil…

  12. Christensen vs Biomet Microfixation alloplastic TMJ implant: Are there improvements? A numerical study.

    Science.gov (United States)

    Ramos, António; Mesnard, Mesnard

    2015-10-01

    The objective of this study was to compare the load transfer mechanism and behavior of two total temporomandibular joint (TMJ) prostheses: Biomet and Christensen TMJ models were simulated. Computed tomography (CT) images from a specific patient were used to generate two models for use in simulation of implantation for the total temporomandibular prostheses. Three finite element models were created in all. One considered the intact temporomandibular joint and two received a temporomandibular implant. In the simulation we considered the five most important muscles acting on the mandible and incisor teeth support. The Christensen model reduced strain in the opposite condyle by around 50% while increasing strain in the implanted condyle. The changes in the posterior side of the implanted condyle present an increase of five times the minimum principal strain, suggesting some bone fatigue. With the Biomet implant, the reduction in strain in the implanted condyle on the posterior side was around 100%, suggesting the possibility of some bone loss proximally near the resection plane. Based on our results, we conclude that in both models the implants influence the behavior of the mandible by improving the symmetry of the mandible and strain distribution. The Biomet implant modifies the behavior of the mandible slightly and presents some improvements over the Christensen TMJ model in strain distribution and tensions in the opposite intact disc similar to the non-implanted situation.

  13. In vitro study of 980nm diode laser in dental implant disinfection

    Directory of Open Access Journals (Sweden)

    Fábio Gonçalves

    2009-12-01

    Full Text Available Objective: To evaluate the potential of 980nm diode laser to reduce bacteria after irradiation of three different dental implant surfaces contaminated with Enterococcus faecalis and Porphyromonas gingivalis, as well as the possible changes in the irradiated implant surfaces.Methods: Seventy two implants with machined surfaces, airborne particle abraded with titanium oxide and acid-etched surfaces were exposed to Enterococcus faecalis and Porphyromonas gingivalis cultures and irradiated with 980nm diode laser with power of 2.5 and 3,0W. After laser treatments, the number of remaining colony-forming units was studied and implant surface morphology was analyzed by scanning electron microscopy. Results: The results showed 100% reduction of the bacteria on the implants irradiated with 3.0W. Moreover, 100% reduction of bacteria was also achieved on the implant surfaces contaminated with Porphyromonas gingivalis when irradiated with 2.5W and 3.0W. Bacteria reduction was not complete for the implants contaminated with Enterococcus faecalis, irradiated with 2.5W and surfaces treated with TiO2 airborne particle abrasion (78.6% and acid etching (49.4%.The scanning electron microscopy analysis showed that at the power settings used, no implant surface changes were found. Conclusion: The 980nm diode laser was effective in decontaminating the Enterococcus faecalis and Porphyromonas gingivalis without promoting surface alteration in the implants.

  14. 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.

  15. 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.

  16. Evaluation of implant osseointegration success: Retrospective study at update course

    OpenAIRE

    Moraes, Michelle Bianchi de; Unesp; Toledo, Vivian Graziele Leite de; School of Dentistry – Institute of Science and Technology – UNESP – Univ Estadual Paulista – São José dos Campos – SP – Brazil.; Nascimento, Rodrigo Dias; Department of Diagnosis and Surgery – School of Dentistry – Institute of Science and Technology – UNESP – Univ Estadual Paulista – São José dos Campos – SP – Brazil.; Gonçalves, Fernanda de Cássia Papaiz; Department of Dental Materials and Prosthodontics – School of Dentistry – Institute of Science and Technology – UNESP – Univ Estadual Paulista – São José dos Campos – SP – Brazil.; Raldi, Fernando Vagner; Department of Diagnosis and Surgery – School of Dentistry – Institute of Science and Technology – UNESP – Univ Estadual Paulista – São José dos Campos – SP – Brazil.

    2015-01-01

    Objective: With the scientific and technological advances, the life expectancy of the population has increased over the years. With the advent of dental implants, a new possibility of treatment for oral rehabilitation was created to help or even help overcome the limits of conventional fixed dentures, removable and mainly total. Compared to conventional rehabilitation treatment on natural teeth, rehabilitation on implants has higher rates of success and longevity. Material and Methods: For th...

  17. Postoperative irradiation after implant placement: A pilot study for prosthetic reconstruction

    Science.gov (United States)

    Keum, Ki Chang; Kim, Jun Won; Shim, June-Sung; Jung, Han-Sung; Park, Kyeong-Mee

    2016-01-01

    PURPOSE On maxillofacial tumor patients, oral implant placement prior to postoperative radiotherapy can shorten the period of prosthetic reconstruction. There is still lack of research on effects of post-implant radiotherapy such as healing process or loading time, which is important for prosthodontic treatment planning. Therefore, this study evaluated the effects of post-implant local irradiation on the osseointegration of implants during different healing stages. MATERIALS AND METHODS Custom-made implants were placed bilaterally on maxillary posterior edentulous area 4 weeks after extraction of the maxillary first molars in Forty-eight Sprague-Dawley rats. Experimental group (exp.) received radiation after implant surgery and the other group (control) didn't. Each group was divided into three sub-groups according to the healing time (2, 4, and 8 week) from implant placement. The exp. group 1, 2 received 15-Gy radiation 1 day after implant placement (immediate irradiation). The exp. group 3 received 15-Gy radiation 4 weeks after implant placement (delayed irradiation). RESULTS The bone mineral density (BMD) was significantly lower in the immediate irradiation groups. BMD was similar in the delayed irradiation group and the control group. The irradiated groups exhibited a lower bone-to-implant contact ratio, although the difference was not statistically significant. The irradiated groups also exhibited a significantly lower bone volume and higher empty lacuna count than the control groups. No implant failure due to local irradiation was found in this study. CONCLUSION Within the limits of this study, the timing of local irradiation critically influences the bone healing mechanism, which is related to loading time of prostheses. PMID:27826386

  18. Children with Cochlear Implants and Developmental Disabilities: A Language Skills Study with Developmentally Matched Hearing Peers

    Science.gov (United States)

    Meinzen-Derr, Jareen; Wiley, Susan; Grether, Sandra; Choo, Daniel I.

    2011-01-01

    The number of children receiving cochlear implants (CIs) with significant disabilities in addition to their deafness has increased substantially. Unfortunately, children with additional disabilities receiving CIs have largely been excluded from studies on cochlear implant outcomes. Thus limited data exists on outcomes in this population to guide…

  19. 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

    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...

  20. 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...

  1. 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

  2. The Development of Falling Intonation in Young Children with Cochlear Implants: A 2-Year Longitudinal Study

    Science.gov (United States)

    Snow, David P.; Ertmer, David J.

    2013-01-01

    This article describes the development of intonation in 12 cochlear implant (CI) recipients. In a previously reported study of the first year of CI use, children who were implanted late (after 24 months) acquired intonation more rapidly than the younger participants. The older children's advantage is plausibly owing to their greater maturity.…

  3. Study of phonological awareness of preschool and school aged children with cochlear implant and normal hearing.

    Science.gov (United States)

    Rastegarianzadeh, Niloufar; Shahbodaghi, Mohammadrahim; Faghihzadeh, Soghrat

    2014-09-01

    The primary purpose of this study was to assess whether very early access to speech sounds provided by the cochlear implant enables children to develop age-appropriate phonological awareness abilities in their preschool and school years. A secondary purpose of this study was to examine whether children who had cochlear implantation before 18 months of age will develop better skills in phonological awareness than children who had cochlear implants in 18-36 months of age. A third purpose of this study was to examine whether some factors like the child's age or sex would have any effects on developing of age-appropriate phonological awareness abilities. 48 children with 70 to 95 months of age who had been utilizing their cochlear implant(s) before 36 months of age (CI group) and 30 normal hearing peers (NH group) were enrolled in this study. Child's age had a significant effect on phonological awareness, but sex had absolutely no effect in each group. Children in the cochlear implanted group were outperformed by their normal hearing peers in the area of phonological awareness, especially in phonemic awareness. The age of implantation was another significant variable. Although children with a younger age at implantation got better scores in phonological awareness test, they were outperformed by their normal hearing peers in this area.

  4. 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

    2012-01-01

    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 ma

  5. One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study

    Directory of Open Access Journals (Sweden)

    A. Siddiqi

    2016-01-01

    Full Text Available 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.

  6. One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study

    Science.gov (United States)

    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. PMID:28058261

  7. Experimental acrylonitrile butadiene styrene and polyamide evisceration implant: a rabbit clinical and histopathology study

    Directory of Open Access Journals (Sweden)

    D.C. Gomes Júnior

    Full Text Available ABSTRACT The purpose of this study was to evaluate acrylonitrile butadiene styrene (ABS and polyamide implants in rabbits submitted to evisceration at the macroscopic and microstructure level and to assess clinical response and histopathological changes as well. For the experimental study implants of 12mm diameter were prepared by rapid prototyping, weighed and the outer and inner surfaces evaluated macroscopically and by electron microscopy. In addition, a compression test was performed and ultrastructural damage was then determined. After evisceration of the left eyeball, nine New Zealand rabbits received ABS implants and nine others received polyamide implants. The animals were assessed daily for 15 days after surgery and every seven days until the end of the study (90 days. Histopathological evaluation was performed at 15, 45 and 90 days after surgery. The ABS implants weighed approximately 0.44g, while the polyamide ones weighed 0.61g. Scanning electron microscopy demonstrated that the ABS implants had regular-sized, equidistant micropores, while the polyamide ones showed micropores of various sizes. The force required to fracture the ABS implant was 14.39 ±0.60 Mpa, while for the polyamide one, it was 16.80 ±1.05 Mpa. Fifteen days after surgery, we observed centripetal tissue infiltration and scarce inflammatory infiltrate. Implants may be used in the filling of anophthalmic cavities, because they are inert, biocompatible and allow tissue integration.

  8. Periodontal parameters of osseointegrated dental implants. A 4-year controlled follow-up study.

    Science.gov (United States)

    Nishimura, K; Itoh, T; Takaki, K; Hosokawa, R; Naito, T; Yokota, M

    1997-08-01

    The aim of this study was to evaluate the periodontal parameters of osseointegrated dental implants. The condition of the peri-implant mucosa was assessed using periodontal parameters, i.e., of plaque index, bleeding on probing, probing pocket depth, probing attachment level and Periotest scores as well as a radiographic parameter, over a 4-year follow-up period. 32 non-submerged ITI dental implants, all placed in the mandible, were studied in 12 patients who had good oral hygiene. All patients were regularly recalled at 6-month intervals. The overall implant success rate was 100%. None of the implants showed any signs of inflammation, radiographic bone loss or any detectable mobility during the follow-up period. Methods similar to those used to evaluate the natural dentition were effectively employed to assess the clinical status of the dental implants. The diagnostic value of these parameters could not, however, be determined from this study due to the absence of any peri-implant tissue complications. The results indicated that some periodontal parameters of healthy peri-implant mucosa might be slightly different from healthy periodontal tissue.

  9. Study of corrosion between a titanium implant and dental alloys.

    Science.gov (United States)

    Reclaru, L; Meyer, J M

    1994-06-01

    The infiltration of saliva into the multi-metallic structures on titanium implants brings different types of alloys into temporary or permanent contact. In this way a galvanic cell is established as a result of their potential difference. The galvanic cell phenomenon is compounded by another type of corrosion resulting from the geometry of the assembly: localized crevice corrosion. Fifteen galvanic couples (Ti/gold-based alloys, Ti/palladium-based alloy and Ti/non-precious alloys) were studied. Various electrochemical parameters (Ecorr, Ecommon, Ecouple corr, Ecrevice, icorr, icouple corr and Tafel slopes) were analysed. The galvanic currents measured are of the same order of magnitude (except Ti/stainless steel). They remain low. Application of the mixed-potential theory shows that titanium in coupling with the alloys studied will be under either cathodic or anodic control. According to the results obtained, an alloy that is potentially usable for superstructures in a galvanic coupling with titanium must fulfil a certain number of parameters: in a coupling, titanium must have a weak anodic polarization; the current generated by the galvanic cell must also be weak; the crevice potential must be markedly higher than the common potential.

  10. Blood Facts and Statistics

    Science.gov (United States)

    ... Facts and Statistics Printable Version Blood Facts and Statistics Facts about blood needs Facts about the blood ... to Top Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells ...

  11. Bacteriophage therapy in implant-related infections: an experimental study.

    Science.gov (United States)

    Yilmaz, Cengiz; Colak, Mehmet; Yilmaz, Banu Coskun; Ersoz, Gulden; Kutateladze, Mzia; Gozlugol, Mehmet

    2013-01-16

    Implant-related infections with bacteria resistant to multiple antibiotics represent one of the major problems in orthopaedic surgery. It was our hypothesis that local application of bacteriophages, which are bacteria-destroying viruses, would be effective against biofilm-forming bacteria. An implant-related infection model was created using methicillin-resistant Staphylococcus aureus (MRSA) in forty-eight rats and Pseudomonas aeruginosa in another forty-eight rats. Each group was divided into four subgroups; one subgroup received a bacterium-specific bacteriophage (Sb-1 in the MRSA group and PAT14 in the Pseudomonas aeruginosa group), one received antibiotic for fourteen days (20 mg/kg/day teicoplanin in the MRSA group, and 120 mg/kg/day imipenem + cilastatin and 25 mg/kg/day amikacin in the Pseudomonas group), one received antibiotic and bacteriophage, and one received no treatment. Animals receiving bacteriophage therapy were injected locally with 107 bacteriophages in a 0.1-mL suspension on three consecutive days. All animals were killed on the fifteenth day after initiation of treatment, and the tibia was excised. Results were assessed with use of microbiology, light microscopy, and electron microscopy. In the MRSA group, the antibiotic administration significantly decreased the number of colony-forming units per subject in quantitative cultures (control subgroup, 50,586; bacteriophage, 30,788; antibiotic, 17,165; antibiotic + bacteriophage, 5000; p = 0.004 for the comparison of the latter group with the control). Biofilm was absent only in the antibiotic + bacteriophage subgroup. In the Pseudomonas group, the number of colony-forming units per subject in quantitative cultures was significantly lower in each treatment subgroup compared with the control subgroup (control subgroup, 14,749; bacteriophage, 6484 [p = 0.016]; antibiotic, 2619 [p = 0.01]; antibiotic + bacteriophage, 1705 [p bacteriophage subgroup was also significantly lower than the values in the

  12. Effect of different lateral occlusion schemes on peri-implant strain: A laboratory study

    Science.gov (United States)

    Lo, Jennifer; Palamara, Joseph

    2017-01-01

    PURPOSE This study aims to investigate the effects of four different lateral occlusion schemes and different excursions on peri-implant strains of a maxillary canine implant. MATERIALS AND METHODS Four metal crowns with different occlusion schemes were attached to an implant in the maxillary canine region of a resin model. The included schemes were canine-guided (CG) occlusion, group function (GF) occlusion, long centric (LC) occlusion, and implant-protected (IP) occlusion. Each crown was loaded in three sites that correspond to maximal intercuspation (MI), 1 mm excursion, and 2 mm excursion. A load of 140 N was applied on each site and was repeated 10 times. The peri-implant strain was recorded by a rosette strain gauge that was attached on the resin model buccal to the implant. For each loading condition, the maximum shear strain value was calculated. RESULTS The different schemes and excursive positions had impact on the peri-implant strains. At MI and 1 mm positions, the GF had the least strains, followed by IP, CG, and LC. At 2 mm, the least strains were associated with GF, followed by CG, LC, and IP. However, regardless of the occlusion scheme, as the excursion increases, a linear increase of peri-implant strains was detected. CONCLUSION The peri-implant strain is susceptible to occlusal factors. The eccentric location appears to be more influential on peri-implant strains than the occlusion scheme. Therefore, adopting an occlusion scheme that can reduce the occurrence of occlusal contacts laterally may be beneficial in reducing peri-implant strains. PMID:28243391

  13. Vestibular Dysfunctions in Cochlear Implant Patients; A Vestibular Evoked Myogenic Potential Study

    Directory of Open Access Journals (Sweden)

    Masoud Motasaddi Zarandy

    2011-12-01

    Full Text Available Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years and 30 normal hearing individuals (mean age 24-27 years as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48% from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

  14. Titanium implant impairment and surrounding muscle cell death following neuro-myoelectrostimulation: An in vivo study.

    Science.gov (United States)

    Lecocq, Mathieu; Félix, Marie-Solenne; Linares, Jean-Marc; Chaves-Jacob, Julien; Decherchi, Patrick; Dousset, Erick

    2015-11-01

    Electrical currents have deleterious effects on biomedical metallic implants. However, following arthroplasty, neuro-myoelectrostimulation (NMES) is often used in patient rehabilitation. Such a rehabilitation technique could compromise patient recovery through deleterious effects on metallic alloys and biological tissues. The purpose of our study was to assess the effects of NMES on a Ti6Al4V implant placed in a rat tibial crest and the surrounding muscle tissues. This in vivo study allowed to bring to the fore the prosthesis behavior under mechanical and electromagnetic loads induced by NEMS stimulation. After 3 weeks, implant-to-bone adhesion significantly decreased in stimulated animals compared with nonstimulated animals. Surface mapping indicated titanium implant degradation after NMES. Furthermore, NMES alone did not induce muscle damage contrary to that found in implanted animals. The muscle damage rate was significantly higher in implanted and stimulated animals compared with implanted-only animals. It seems obvious that rehabilitation programs using the NMES technique could induce early deterioration of biomaterial employed for surgical implants. Clinicians should reconsider the use of NMES as a rehabilitation technique for patients with titanium prostheses.

  15. Progressive plateau root form dental implant osseointegration: A human retrieval study.

    Science.gov (United States)

    Gil, Luiz F; Suzuki, Marcelo; Janal, Malvin N; Tovar, Nick; Marin, Charles; Granato, Rodrigo; Bonfante, Estevam A; Jimbo, Ryo; Gil, Jose N; Coelho, Paulo G

    2015-08-01

    Although preclinical and sparse human histology retrieval studies have shown that the interface between implant and bone is constantly remodeling, no human retrieval database has been developed to determine the effect of functional loading time and other clinical/implant design variables on osseointegration. The present study tested the hypothesis that bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) increase over functional loading time around dental implants. Due to prosthetic retreatment reasons, 93 human implant retrievals from the same manufacturer (Bicon LLC, Boston, MA, USA) were obtained over a period of approximately 15 years. The retrieved implants were under functional loading from 120 days to ∼18 years and were histomorphologic/metrically evaluated. BIC/BAFO were assessed as a function of multiple independent variables: implant surface type, diameter, length, jaw (maxilla/mandible), region (anterior/posterior), and time of functional loading. The results showed that both BIC and BAFO increased over time independently of implant design/clinical variables, supporting the postulated hypothesis.

  16. Clinical, microbiological, and immunological aspects of healthy versus peri-implantitis tissue in full arch reconstruction patients: a prospective cross-sectional study

    OpenAIRE

    Ata-Ali, Javier; Flichy-Fernández, Antonio Juan; Alegre-Domingo, Teresa; Ata-Ali, Fadi; Palacio, Jose; Peñarrocha-Diago, Miguel

    2015-01-01

    Background Due to the world-wide increase in treatments involving implant placement, the incidence of peri-implant disease is increasing. Late implant failure is the result of the inability to maintain osseointegration, whose most important cause is peri-implantitis. The aim of this study was to analyze the clinical, microbiological, and immunological aspects in the peri-implant sulcus fluid (PISF) of patients with healthy dental implants and patients with peri-implantitis. Methods PISF sampl...

  17. A STUDY OF EFFICACY AND SAFETY PROFILE WITH SUB DERMAL SINGLE ROD CONTRACEPTIVE IMPLANT IMPLANON

    Directory of Open Access Journals (Sweden)

    Sapna

    2015-03-01

    Full Text Available INTRODUCTION: The development of sub dermal contraceptive implant has been an important improvement in current contraceptive technology and to a good alternative to offer well established contraceptive method. Hormonal implant must show high efficacy, high acceptabilit y and rapid return of fertility after removal by maintaining a sustained release of progesterone, the contraceptive effect of the implant can be obtained with a much smaller daily dose than when administering the same steroid by an oral or intramuscular ro ute. Sub dermal implant s are also independent of user compliance which remains a determinant factor in the efficacy of most contraceptive methods. In addition after removal of the hormonal implant, fertility returns almost immediately. They contain only pr ogestogen, these implant may also be used by women who cannot tolerate oestrogen or by women for whom oestrogen is contraindicated. The availability of new innovative contraceptive implant system such as implanon is very important to offer couples alternat ive methods to plan size of their family more efficiently. OBJECTIVES: To study efficacy and safety profile of single rod sub dermal contraceptive device implant implanon. To evaluate the vaginal bleeding patterns observed during the use of implanon. To as sess the acceptability of the contraceptive device as indicated by discontinuation rates. MATERIAL AND METHODS: S tudy was carried in OBG department of RMC Kanpur on healthy female volunteers having regular menstruation & at least one living child. RESULT: The result of this study was excellent in terms of contraception with pearl index of 0, almost one third cases were having in frequent bleeding episode. CONCLUSION: The study was conducted on 110 women of age 20 - 35 years with at least one living child and having regular menstrual period, in present study half of cases discontinued implant due to no fix pattern of bleeding and failure was o%, efficacy of this implant

  18. 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.

  19. High temperature annealing studies of strontium ion implanted glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Odutemowo, O.S., E-mail: u12052613@tuks.co.za [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Malherbe, J.B.; Prinsloo, L.; Langa, D.F. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Wendler, E. [Institut für Festkörperphysik, Friedrich-Schiller University, Jena (Germany)

    2016-03-15

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 10{sup 16} ions/cm{sup 2} at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

  20. High temperature annealing studies of strontium ion implanted glassy carbon

    Science.gov (United States)

    Odutemowo, O. S.; Malherbe, J. B.; Prinsloo, L.; Langa, D. F.; Wendler, E.

    2016-03-01

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 1016 ions/cm2 at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

  1. [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.

  2. Influence of direct laser fabrication implant topography on type IV bone: a histomorphometric study in humans.

    Science.gov (United States)

    Shibli, Jamil Awad; Mangano, Carlo; D'avila, Susana; Piattelli, Adriano; Pecora, Gabriele E; Mangano, Francesco; Onuma, Tatiana; Cardoso, Luciana A; Ferrari, Daniel Sanchez; Aguiar, Kelly C; Iezzi, Giovanna

    2010-05-01

    The aim of this histologic study was to evaluate the influence of the direct laser fabrication (DFL) surface topography on bone-to-implant contact (BIC%), on bone density in the threaded area (BA%) as well as bone density outside the threaded area (BD%) in type IV bone after 8 weeks of unloaded healing. Thirty patients (mean age 51.34 +/- 3.06 years) received 1 micro-implant (2.5-mm diameter and 6-mm length) each during conventional implant surgery in the posterior maxilla. Thirty micro-implants with three topographies were evaluated: 10 machined (cpTi); 10 sandblasted and acid etched surface (SAE) and 10 DFL micro-implants. After 8 weeks, the micro-implants and the surrounding tissue were removed and prepared for histomorphometric analysis. Four micro-implants (2 cpTi, 1 SAE and 1DLF) showed no osseointegration after the healing period. Histometric evaluation indicated that the mean BIC% was higher for the DFL and SAE surfaces (p = 0.0002). The BA% was higher for the DFL surface, although there was no difference with the SAE surface. The BD% was similar for all topographies (p > 0.05). Data suggest that the DFL and SAE surfaces presented a higher bone-to-implant contact rate compared with cpTi surfaces under unloaded conditions, after a healing period of 8 weeks.

  3. 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.

  4. Bone response to machined and resorbable blast material titanium implants: an experimental study in rabbits.

    Science.gov (United States)

    Piattelli, Maurizio; Scarano, Antonio; Paolantonio, Michele; Iezzi, Giovanna; Petrone, Giovanna; Piattelli, Adriano

    2002-01-01

    The aim of the present study was a comparison of implants' responses to a machined surface and to a surface sandblasted with hydroxyapatite (HA) particles (resorbable blast material [RBM]). Threaded machined and RBM, grade 3, commercially pure, titanium, screw-shaped inplants were used in this study. Twenty-four New Zealand white mature male rabbits were used. The inplants were inserted into the articular femoral knee joint according to a previously described technique. Each rabbit received 2 inplants, 1 test (RBM) and 1 control (machined). A total of 48 implants (24 control and 24 test) were inserted. The rabbits were anesthetized with intramuscular injections of fluanisone (0.7 mg/ kg body weight) and diazepam (1.5 mg/kg b.wt.), and local anesthesia was given using 1 mL of 2% lidocaine/adrenalin solution. Two rabbits died in the postoperative course. Four animals were euthanatized with an overdose of intravenous pentobarbital after 1, 2, 3, and 4 weeks; 6 rabbits were euthanatized after 8 weeks. A total of 44 implants were retrieved. The specimens were processed with the Precise 1 Automated System to obtain thin ground sections. A total of 3 slides were obtained for each implant. The slides were stained with acid and basic fuchsin and toluidine blue. The slides were observed in normal transmitted light under a Leitz Laborlux microscope, and histomorphometric analysis was performed. With the machined implants, it was possible to observe the presence of bone trabeculae near the implant surface at low magnification. At higher magnification many actively secreting alkaline phosphatasepositive (ALP+) osteoblasts were observed. In many areas, a not yet mineralized matrix was present. After 4 to 8 weeks, mature bone appeared in direct contact with the implant surface, but in many areas a not yet mineralized osteoid matrix was interposed between the mineralized bone and implant surface. In the RBM implants, many ALP+ osteoblasts were present and in direct contact with

  5. 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.

  6. Photoemission studies of amorphous silicon induced by P + ion implantation

    Science.gov (United States)

    Petö, G.; Kanski, J.

    1995-12-01

    An amorphous Si layer was formed on a Si (1 0 0) surface by P + implantation at 80 keV. This layer was investigated by means of photoelectron spectroscopy. The resulting spectra are different from earlier spectra on amorphous Si prepared by e-gun evaporation or cathode sputtering. The differences consist of a decreased intensity in the spectral region corresponding to p-states, and appearace of new states at higher binding energy. Qualitativity similar results have been reported for Sb implanted amorphous Ge and the modification seems to be due to the changed short range order.

  7. 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.

  8. Biomechanical evaluation of implant-supported prosthesis with various tilting implant angles and bone types in atrophic maxilla: A finite element study.

    Science.gov (United States)

    Gümrükçü, Zeynep; Korkmaz, Yavuz Tolga; Korkmaz, Fatih Mehmet

    2017-07-01

    The purpose of this study is to evaluate and compare bone stress that occurs as a result of using vertical implants with simultaneous sinus augmentation with bone stress generated from oblique implants without sinus augmentation in atrophic maxilla. Six, three-dimensional (3D) finite element (FE) models of atrophic maxilla were generated with SolidWorks software. The maxilla models were varied for two different bone types. Models 2a, 2b and 2c represent maxilla models with D2 bone type. Models 3a, 3b and 3c represent maxilla models with D3 bone type. Five implants were embedded in each model with different configurations for vertical implant insertion with sinus augmentation: Model 2a/Model 3a, 30° tilted insertion; Model 2b/Model 3b and 45° tilted insertion; Model 2c/Model 3c. A 150 N load was applied obliquely on the hybrid prosthesis. The maximum von Mises stress values were comparatively evaluated using color scales. The von Mises stress values predicted by the FE models were higher for all D3 bone models in both cortical and cancellous bone. For the vertical implant models, lower stress values were found in cortical bone. Tilting of the distal implants by 30° increased the stress in the cortical layer compared to vertical implant models. Tilting of the distal implant by 45° decreased the stress in the cortical bone compared to the 30° models, but higher stress values were detected in the 45° models compared to the vertical implant models. Augmentation should be the first treatment option in atrophic maxilla in terms of biomechanics. Tilted posterior implants can create higher stress values than vertical posterior implants. During tilting implant planning, the use of a 45° tilted implant results in better biomechanical performance in peri-implant bone than 30° tilted implant due to the decrease in cantilever length. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Fact File

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The COMMUNIST PARTY OF CHINA (CPC) celebrates its 90th anniversary in 2011. To help our readers gain a deeper insight of the CPC, ChinAfrica asked Li Wei, Associate Research Fellow with the Institute for Theory Studies of the Communist Youth League of China

  10. Mucosal inflammation and incidence of crestal bone loss among implant patients: a 10-year study.

    Science.gov (United States)

    Cecchinato, Denis; Parpaiola, Andrea; Lindhe, Jan

    2014-07-01

    The objective of this prospective study was to determine the prevalence and incidence of marginal bone loss and, in addition, peri-implantitis in subjects and implant sites after 10 years in function. One hundred and thirty-three subjects with a total of 407 implants that had been in function for about 5 years attended a follow-up visit in 2007 (visit 2; V2). 100 of the 133 subjects returned for a new clinical and radiographic examination in 2012 (visit 3; V3). The clinical examination included assessment of "bleeding on probing" (BoP+) and "probing pocket depth." Subjects with implant sites that in the radiograph exhibited crater-shaped marginal bone loss of >0.5 mm were identified as losers. During the interval between V2 and V3 (about 5 years), 13 implants in 7 subjects exhibited progressive bone loss and were removed. The overall amount of crestal bone loss that had occurred at the remaining implants between visit 1 (V1; ≥1 year of loading) and V3 (10 years) was small (0.36 ± 1.4 mm). The bone-level reduction was twice as great between V2 and V3 as between V1 and V2. Forty subjects and 75 (26%) implant sites exhibited marginal bone loss of >0.5 mm between V1 and V3. In the interval between V2 and V3, 37 new implant sites lost significant amounts of bone. During the entire 10-year period (V1-V3), 12% of patients and 5% of implants displayed signs of peri-implantitis (bone loss >0.5 mm, BoP+, PPD ≥6 mm), while in the V2-V3 interval, the corresponding numbers were 10% (patients) and 4% (implant sites). Sites with marginal bone loss of ≥1 mm were not common among implant patients. Peri-implantitis occurred in about 10% of patients and 4% of implant sites. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. A Longitudinal Study in Adults with Sequential Bilateral Cochlear Implants: Time Course for Individual Ear and Bilateral Performance

    Science.gov (United States)

    Reeder, Ruth M.; Firszt, Jill B.; Holden, Laura K.; Strube, Michael J.

    2014-01-01

    Purpose: The purpose of this study was to examine the rate of progress in the 2nd implanted ear as it relates to the 1st implanted ear and to bilateral performance in adult sequential cochlear implant recipients. In addition, this study aimed to identify factors that contribute to patient outcomes. Method: The authors performed a prospective…

  12. 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.

  13. Three-Dimensional Evaluation of Implant Positioning in the Maxillary Sinus Septum: A Retrospective Study

    Science.gov (United States)

    Dragan, Eliza; Guillaume, Odri A.; Haba, Danisia; Olszewski, Raphael

    2015-01-01

    Background The aim of this study was to simulate implant placement in the maxillary sinus septum, as a potential alternative site to avoid sinus grafting. Material/Methods One hundred partially or completely edentulous patients, with their maxillary sinus septum present in the edentulous region, were selected from the database of the Department of Maxillofacial Surgery, Cliniques Universitaires Saint Luc, Bruxelles, Belgium. Three-dimensional (3D) reconstructions were created using 3D planning software. 3D reconstructions were performed for each maxillary sinus. Using the software implant library, the implants that presented the best fit with the maxillary sinus septum and that followed the established inclusion criteria were selected. Results All of the implants were inserted in premolar and molar regions. Most implants were inserted in the position of the second molar (21 of 55) or in the position of the first molar (17 of 55). In all sites the most frequently used implant was 4 mm in diameter and 7 mm in height. The mean coronal angle for the implant was 80.19±17.13 degrees and the mean sagittal angle was 94.83±9.94 degrees. The septal height represents 38.13% of the total available bone height (ABH). The mean percentage of the septum used to insert the implants was 47.33±2.47%. The septum increased the available bone height by a mean value of 2.18±1.47 mm. In 45 cases, the septa did not permit implant placement. Conclusions In completely edentulous patients, inserting implants in sinus septa does not exclude the need for sinus grafting, but in partially edentulous patients, this minimally invasive technique is an alternative to subantral augmentation. PMID:26363865

  14. A 10-Year Prospective Study of Single Tooth Implants Placed in the Anterior Maxilla

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2012-01-01

    in this study. Ten implants were placed with an early placement protocol, that is, 4 weeks after tooth extraction, whereas the other 10 implants were placed with a conventional delayed placement protocol, for example, 12 weeks after tooth extraction. At the baseline and at the annual re-examinations, pain from......Purpose: The aim of the study was to evaluate the biological and technical outcomes of early and delayed placed single tooth implants after 10 years of follow-up. Materials and Methods: Twenty consecutive patients who needed a single tooth replacement in the anterior maxilla were included...

  15. Communication Intervention for Children with Cochlear Implants: Two Case Studies.

    Science.gov (United States)

    Ertmer, David J.; Leonard, Jeannette S.; Pachuilo, Michael L.

    2002-01-01

    This article describes the intervention programs attended and progress made by two children (ages 3 and 7) who exhibited considerable differences in benefit from their cochlear implants. Their intervention programs employed both analytical and synthetic auditory training and emphasized the development of speech production and language skills.…

  16. Study of boron implantation in Ag-Si layer structures

    Energy Technology Data Exchange (ETDEWEB)

    Pelikan, L. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Elektrotechnicka); Rybka, V.; Krejci, P. (Tesla, Prague (Czechoslovakia). Vyzkumny Ustav pro Sdelovaci Techniku); Hnatowicz, V.; Kvitek, J. (Ustav Jaderneho Vyzkumu CSKAE, Rez (Czechoslovakia))

    1982-07-16

    The implanted boron depth profiles in samples comprising Si wafers covered with Ag films of various thicknesses are determined experimentally as well as by Monte-Carlo simulation. A complex shape of depth profiles is revealed, which is well reproduced by the calculation.

  17. Comparison of Osteotome and Conventional Drilling Techniques for Primary Implant Stability: An In Vitro Study.

    Science.gov (United States)

    Tsolaki, Ioanna N; Tonsekar, Pallavi P; Najafi, Babak; Drew, Howard J; Sullivan, Andrew J; Petrov, Sofia D

    2016-08-01

    It may be difficult to achieve primary stability in the posterior maxilla because of poor quality and quantity of bone. Studies have shown that the osteotome technique immediately increases bone density thereby increasing primary stability. An in vitro study was conducted to compare the stability achieved by the osteotome and conventional drilling techniques in low density bone. Forty endosseous implant fixtures (n = 40) were inserted in a solid rigid polyurethane block simulating low density (D3) bone. The implants were divided into 4 groups to test 2 variables: (1) implant length (10 mm or 13 mm) and (2) preparation of osteotomy (conventional drilling or osteotome technique). Insertion torque (IT) and resonance frequency analysis (RFA) were measured for each implant. Statistical analysis using one-way ANOVA and Tukey post hoc test was done to study IT and RFA data of the 4 groups. Pearson Correlation test was used to determine the correlation between IT and RFA values of the implants. The IT and RFA values were statistically significant higher using the osteotome technique as compared to conventional drilling (P < 0.0001). Statistically significant higher values were also found for IT and RFA of 13 mm implants as compared to 10 mm implants. A significant correlation was found between insertion torque and RFA values in all 4 groups (r = 0.86, P < 0.0001). The conclusion was that the osteotome technique significantly increased primary stability.

  18. Long-term implant prognosis in patients with and without a history of chronic periodontitis: a 10-year prospective cohort study of the ITI Dental Implant System.

    Science.gov (United States)

    Karoussis, Ioannis K; Salvi, Giovanni E; Heitz-Mayfield, Lisa J A; Brägger, Urs; Hämmerle, Christoph H F; Lang, Niklaus P

    2003-06-01

    The aim of this 10-year study was to compare the failure, success and complication rates between patients having lost their teeth due to periodontitis or other reasons. Fifty-three patients who received 112 hollow screw implants (HS) of the ITI Dental Implant System were divided into two groups: group A - eight patients with 21 implants having lost their teeth due to chronic periodontitis; group B - forty five patients with 91 implants without a history of periodontitis. One and 10 years after surgical placement, clinical and radiographic parameters were assessed. The incidences of peri-implantitis were noticed over the 10 years of regular supportive periodontal therapy. Success criteria at 10 years were set at: pocket probing depth (PPD) periodontitis (group A) was 90.5%, while for the group with no past history of periodontitis (group B) it was 96.5%. Group A had a significantly higher incidence of peri-implantitis than group B (28.6% vs. 5.8%). With the success criteria set, 52.4% in group A and 79.1% of the implants in group B were successful. With a threshold set at PPD periodontitis demonstrated lower survival rates and more biological complications than patients with implants replacing teeth lost due to reasons other than periodontitis during a 10-year maintenance period. Furthermore, setting of thresholds for success criteria is crucial to the reporting of success rates.

  19. Study on the Properties of TiN Coatings on Previously Ion-Implanted Pure Magnesium Surface by MEVVA Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hai; CHEN Fei; WANG Jian-ping

    2007-01-01

    A metal vapor vacuum arc (MEVVA) is used in ion implantation for substrate preparation before the deposition process which would ensure the improvement of mechanical properties of the coating.Ti ion is implanted into pure magnesium surface by MEVVA implanter operated with a modified cathode.Implanting energy is kept at 45 keV and dose is set at 3×1017 cm-2.TiN coatings are deposited by magnetically filtered vacuum-arc plasma source on unimplanted and previously implanted substrates.Microstructure and phase composition are analysed using scanning electron microscopy (SEM) and X-ray diffraction (XRD).The property of corrosion resistance of TiN coatings was studied by CS300P electrochemistry-corrosion workstation,and the main impact factor of the corrosion resistance was also analyzed.

  20. Studies on bilateral cochlear implants at the University of Wisconsin's Binaural Hearing and Speech Laboratory.

    Science.gov (United States)

    Litovsky, Ruth Y; Goupell, Matthew J; Godar, Shelly; Grieco-Calub, Tina; Jones, Gary L; Garadat, Soha N; Agrawal, Smita; Kan, Alan; Todd, Ann; Hess, Christi; Misurelli, Sara

    2012-06-01

    This report highlights research projects relevant to binaural and spatial hearing in adults and children. In the past decade we have made progress in understanding the impact of bilateral cochlear implants (BiCIs) on performance in adults and children. However, BiCI users typically do not perform as well as normal hearing (NH) listeners. In this article we describe the benefits from BiCIs compared with a single cochlear implant (CI), focusing on measures of spatial hearing and speech understanding in noise. We highlight the fact that in BiCI listening the devices in the two ears are not coordinated; thus binaural spatial cues that are available to NH listeners are not available to BiCI users. Through the use of research processors that carefully control the stimulus delivered to each electrode in each ear, we are able to preserve binaural cues and deliver them with fidelity to BiCI users. Results from those studies are discussed as well, with a focus on the effect of age at onset of deafness and plasticity of binaural sensitivity. Our work with children has expanded both in number of subjects tested and age range included. We have now tested dozens of children ranging in age from 2 to 14 yr. Our findings suggest that spatial hearing abilities emerge with bilateral experience. While we originally focused on studying performance in free field, where real world listening experiments are conducted, more recently we have begun to conduct studies under carefully controlled binaural stimulation conditions with children as well. We have also studied language acquisition and speech perception and production in young CI users. Finally, a running theme of this research program is the systematic investigation of the numerous factors that contribute to spatial and binaural hearing in BiCI users. By using CI simulations (with vocoders) and studying NH listeners under degraded listening conditions, we are able to tease apart limitations due to the hardware/software of the CI

  1. Osteotome versus conventional drilling technique for implant site preparation: a comparative study in the rabbit.

    Science.gov (United States)

    Nóbrega, Ana Rita; Norton, Ana; Silva, José Antonio; Silva, José Pedro Dias; Branco, Fernando Morais; Anitua, Eduardo

    2012-06-01

    The aim of this research was to study the influence of the osteotome technique on insertion torque and stability values when compared with conventional surgical drilling of the implant site. A total of 20 implants (4-mm diameter, 8.5-mm long) were placed in the distal femural condyle of 10 New Zealand White rabbits. The implant sites were prepared by using either the conventional drilling technique as a control group (group A) or the osteotome technique (group B). Cutting torque and resonance frequency analyses (RFAs) were conducted at and after implant placement. The resulting values were subjected to correlation and comparative analyses between groups. Insertion torque measurements were conducted at three different levels of implant insertion: crestal, middle, and apical. Group B showed higher mean insertion torque and RFA values (P .05). Bone condensation before implant insertion in low-density bone led to higher mean insertion torque and RFA values. Within the limits of this experimental study, a benefit in using the osteotome technique was observed when dealing with low-density bone. Bone condensation can improve primary stabilization of implants.

  2. Rutherford Backscattering Spectrometry studies of 100 keV nitrogen ion implanted polypropylene polymer

    Science.gov (United States)

    Chawla, Mahak; Aggarwal, Sanjeev; Sharma, Annu

    2017-09-01

    The effect of nitrogen ion implantation on the structure and composition in polypropylene (PP) polymer has been studied. Implantation was carried out using 100 keV N+ ions at different fluences of 1 × 1015, 1 × 1016 and 1 × 1017 ions cm-2 with beam current density of ∼0.65 μA cm-2. Surface morphological changes in the pre- and post-implanted PP specimens have been studied using Rutherford Backscattering Spectrometry (RBS) and UV-Visible Spectroscopy. The spatial distribution of implantation induced modification in the form of carbonization and dehydrogenation in the near surface region of PP matrix, the projected range, retained dose of implanted nitrogen, the various elements present in the implanted layers and their differential cross-sections have been analyzed using RBS spectra. RUMP simulation yielded an increase in the concentration of carbon near the surface from 33 at.% (virgin) to 42 at.% at fluence of 1 × 1017 N+ cm-2. Further, optical absorption has been found to increase with a shift in the absorption edge from UV towards visible region with increasing fluence. UV-Vis absorption spectra also indicate a drastic decrease in optical energy gap from 4.12 eV (virgin) to 0.25 eV (1 × 1017 N+ cm-2) indicating towards the formation of carbonaceous network in the implanted region. All these changes observed using UV-Visible have been further correlated with the outcomes of the RBS characterization.

  3. Occurrence of trigeminocardiac reflex during dental implant surgery: An observational prospective study.

    Science.gov (United States)

    Huang, James I-Sheng; Yu, Hui-Chieh; Chang, Yu-Chao

    2017-10-01

    Trigeminocardiac reflex (TCR) is a clinical phenomenon that manifests as s sudden onset of hemodynamic perturbations. TCR has been reported in cranio-maxillofacial surgery resulting in severe medical risks. Monitoring the hemodynamic changes during cranio-maxillofacial surgery can provide important information to ensure the continuous evaluation of patient's physical conditions. This prospective observational study was conducted to determine the hemodynamic alterations related to the possibly of occurrence of TCR in patients during dental implant surgery. One hundred and thirty-five patients (69 males and 66 females) received dental implant placement were enrolled in this study. The hemodynamic changes were evaluated by monitoring heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse oximetry (SpO2). The above data were collected before, during, and after dental implant surgery. The data demonstrated that the minimal values of HR, SBP, and DBP as well as MABP decreased significantly during operation comparing with the corresponding values before operation (p implant placement in the mandible, patients received dental implant placement in the maxilla had more risks to confront with MABP reduction (OR = 3.98; 95% confidence interval: 1.12-13.2). A significant HR and BP reduction possibly due to TCR can occur during dental implant surgery. Therefore, the dentists should monitor the hemodynamic changes during dental implant surgery to prevent the possible occurrence of medical risks related to TCR. Copyright © 2017. Published by Elsevier B.V.

  4. Survival Rate of Short, Locking Taper Implants with a Plateau Design: A 5-Year Retrospective Study

    Directory of Open Access Journals (Sweden)

    Kemal Özgür Demiralp

    2015-01-01

    Full Text Available Background. Short implants have become popular in the reconstruction of jaws, especially in cases with limited bone height. Shorter implants, those with locking tapers and plateau root shapes, tend to have longer survival times. We retrospectively investigated the cumulative survival rates of Bicon short implants (<8 mm according to patient variables over a 5-year period. Materials and Methods. This study included 111 consecutively treated patients with 371 implants supporting fixed or removable prosthetics. Data were evaluated to acquire cumulative survival rates according to gender, age, tobacco use, surgical procedure, bone quality, and restoration type. Statistics were performed using chi-square, Mann-Whitney, and Kruskal Wallis H tests. Results. The survival rate was 97.3% with, on average, 22.8 months of follow-up. Patients older than 60 years had higher failure rate than the other age groups (P<0.05. Placed region, age, and bone quality had adverse effects on survival rate in the <8 mm implant group with statistically significant difference (P<0.05. Conclusions. Approximately 23-month follow-up data indicate that short implants with locking tapers and plateau-type roots have comparable survival rates as other types of dental implants. However, due to limitations of study, these issues remain to be further investigated in future randomized controlled clinical trials.

  5. Cell attachment on ion implanted titanium surface

    Directory of Open Access Journals (Sweden)

    P.S. Sreejith

    2008-12-01

    Full Text Available Purpose: Of outmost importance for the successful use of an implant is a good adhesion of the surrounding tissue to the biomaterial. In addition to the surface composition of the implant, the surface topography also influences the properties of the adherent cells. In the present investigation, ion implanted and untreated surfaces were compared for cell adhesion and spreading.Design/methodology/approach: The surface topography of the surfaces were analyzed using AFM and the cell studies with SEM.Findings: The results of our present investigation is indicative of the fact that ion implanted titanium surface offer better cell binding affinity compared to untreated/polished surface.Practical implications: Success of non-biodegradable implants will first and foremost depend on biocompatibility, followed by the capacity of the surface topography of the implants to evince desired cell matrix, surface cell matrix interactions. In the present study, the cell growth on ion implanted Ti material is analyzed and discussed.Originality/value: In this paper, we have utilized ion implantation technique, which will produce nano-texturing of the surface without producing any detrimental effects to both the dimensions and properties of the implants.

  6. Experimental study on penetration of dental implants into the maxillary sinus in different depths

    National Research Council Canada - National Science Library

    ZHONG, Weijian; CHEN, Binke; LIANG, Xin; MA, Guowu

    2013-01-01

    ...: The purpose of this study was to investigate the effects of the dental implant penetration into the maxillary sinus cavity in different depths on osseointegration and sinus health in a dog model...

  7. Effects of implant angulation, material selection, and impression technique on impression accuracy: a preliminary laboratory study.

    Science.gov (United States)

    Rutkunas, Vygandas; Sveikata, Kestutis; Savickas, Raimondas

    2012-01-01

    The aim of this preliminary laboratory study was to evaluate the effects of 5- and 25-degree implant angulations in simulated clinical casts on an impression's accuracy when using different impression materials and tray selections. A convenience sample of each implant angulation group was selected for both open and closed trays in combination with one polyether and two polyvinyl siloxane impression materials. The influence of material and technique appeared to be significant for both 5- and 25-degree angulations (P impression accuracy. The open-tray technique was more accurate with highly nonaxially oriented implants for the small sample size investigated.

  8. Monte Carlo studies of positron implantation in elemental metallic and multilayer systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, V.J.; Welch, D.O.; Lynn, K.G.

    1992-01-01

    We have used a Monte Carlo computer code developed at Brookhaven [sup 1,2] to study the implantation profiles of 1-10 keV positrons incident on a wide range of semi-infinite metals and multilayer systems. Our Monte Carlo program accounts for elastic scattering as well as inelastic scattering from core and valence electrons, and includes the excitation of plasmons. The implantation profiles of positrons in many metals as well as Pd/Al, and Al/Co/Si multilayers are presented. Scaling relations and closed-form expressions representing he implantation profiles are also discussed.

  9. Monte Carlo studies of positron implantation in elemental metallic and multilayer systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, V.J.; Welch, D.O.; Lynn, K.G.

    1992-12-01

    We have used a Monte Carlo computer code developed at Brookhaven {sup 1,2} to study the implantation profiles of 1-10 keV positrons incident on a wide range of semi-infinite metals and multilayer systems. Our Monte Carlo program accounts for elastic scattering as well as inelastic scattering from core and valence electrons, and includes the excitation of plasmons. The implantation profiles of positrons in many metals as well as Pd/Al, and Al/Co/Si multilayers are presented. Scaling relations and closed-form expressions representing he implantation profiles are also discussed.

  10. 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.

  11. Surface characteristics and cell adhesion: a comparative study of four commercial dental implants.

    Science.gov (United States)

    Liu, Ruohong; Lei, Tianhua; Dusevich, Vladimir; Yao, Xiamei; Liu, Ying; Walker, Mary P; Wang, Yong; Ye, Ling

    2013-12-01

    The aims of this study were to compare surface properties of four commercial dental implants and to compare those implant systems' cell adhesion, which may be affected by the surface properties, and to provide scientific information on the selection of implants for clinicians. The surface properties of four commonly used dental implants (3i Nanotite™, Astra OsseoSpeed™, Nobel Biocare TiUnite®, and Straumann SLActive®) were studied using MicroSpy profiler, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and Raman microspectroscopy. Primary mouse alveolar bone cells were cultured on the surface of implants from the four companies. After 48-hour culture, SEM in combination with a quantitative analysis of SEM images was used to examine the cell adhesion. Cell adhesion rates (ratios of cell surface to implant surface) among different systems were compared. Distinct differences were found among these implants. Comparisons of roughness among three locations: flank, top, and valley within the same implant system, or in the same location among different implants were made. Generally Astra and Straumann systems showed the roughest surface, whereas 3i showed the smoothest surface. Multiple cracks were found on the surface of the Nobel Biocare system, which also had a dramatically lower level of titanium. In addition, rutile phase of titanium oxide was found in 3i, Astra, and Straumann systems, and anatase phase of titanium oxide was only detected in the Nobel Biocare system. After 48-hour culture, Astra and Straumann systems displayed the highest cell adhesion at the areas of flank, top, and valley of the implant surface. Primary cells also reached confluence on the valley, but significantly less in the 3i system. Nobel Biocare showed the least cell adhesion on the flank and valley. Implant systems have distinct differences in surface properties, leading to different cell adhesion results. Further in vivo study is needed to study the impact of

  12. 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)

  13. 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 wa...

  14. 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...

  15. State Health Facts

    Science.gov (United States)

    ... Facts Home State Health Facts Search State Health Facts: Choose Category - or - Choose Location Demographics and the ... Expansion Enrollment Featured State Data Resources Medicaid State Fact Sheets What percentage of people are covered by ...

  16. Effect of platform switching on the peri-implant bone: A finite element study

    Science.gov (United States)

    Martínez-González, Amparo; Peiró, Germán; Ródenas, Juan-José; López-Mollá, María-Victoria

    2015-01-01

    Background There exists a relation between the presence and location of the micro-gap and the loss of peri implant bone. Several authors have shown that the treatments based on the use of platform switching result in less peri-implant bone loss and an increased tissue stability. The purpose of this study was to analyse the effect of the platform switching on the distribution of stresses on the peri-implant bone using the finite element method. Material and Methods A realistic 3D full-mandible finite element model representing cortical bone and trabecular bone was used to study the distribution of the stress on the bone induced by an implant of diameter 4.1 mm. Two abutments were modelled. The first one, of diameter 4.1 mm, was used in the reference model to represent a conventional implant. The second one, of diameter 3.2 mm, was used to represent the implant with platform switching. Both models were subjected to axial and oblique masticatory loads. Results The analyses showed that, although no relevant differences can be found for the trabecular bone, the use of platform switching reduces the maximum stress level in the cortical bone by almost 36% with axial loads and by 40% with oblique loads. Conclusions The full 3D Finite Element model, that can be used to investigate the influence of other parameters (implant diameter, connexion type, …) on the biomechanical behaviour of the implant, showed that this stress reduction can be a biomechanical reasons to explain why the platform switching seems to reduce or eliminate crestal bone resorption after the prosthetic restoration. Key words:Dental implant, platform switching, finite element method. PMID:26535094

  17. Study of surface exfoliation on 6H-SiC induced by H2+ implantation

    Science.gov (United States)

    Zhang, L.; Li, B. S.

    2017-03-01

    The effect of lattice damage generated by the H2+-implantation on exfoliation efficiency in 6H-SiC wafers is investigated. 6H-SiC wafers were implanted with 134 keV H2+ ions to ion fluences from 1.5×1016 to 5×1016 H2+ cm-2 and subsequently annealed at temperatures from 973 K to 1373 K. The samples were studied by a combination of optical microscopy and transmission electron microscopy. Only after 1373 K annealing for 15 min, blisters and exfoliation occur on the H2+-implanted sample surface. With increasing the implantation fluences from 1.5×1016 to 3.75×1016 H2+ cm-2, the exfoliation mean size decreases, while the exfoliation density increases. For the highest fluence of 5×1016 H2+ cm-2, seldom exfoliations occur on the sample surface. Microstructure analysis shows that exfoliation efficiency is largely controlled by the H2+-implantation-induced lattice damage. The depth of the microcrack is related to the implantation fluence. The effect of implantation fluence on dislocation loops, platelet nucleation and growth is investigated.

  18. [Effect of periodontal regeneration using collagen-coated synthetic bone implant materials. Histopathological study].

    Science.gov (United States)

    Sugaya, A

    1989-09-01

    Granulated artificial bone implant materials such as hydroxyapatite (HAP) and tricalcium phosphate (TCP) have been frequently used in attempts to restore periodontal tissue lost as a result periodontitis. However, these materials are considered insufficient for the maintenance and stability of granules at sites losing bone, for active bone formation, or for periodontal ligament regeneration. We have now developed a complex consisting of HAP or TCP coated with atelocollagen (which has recently received attention as a biomaterial) and have conducted experiments to determine the effects of this material on the reconstruction of periodontal tissue. Implantations were performed using a HAP-atelocollagen complex, TCP-atelocollagen complex, HAP and TCP at three-wall bone defect sites in experimentally-induced periodontitis in dogs. A control group without the implants was included in the study. Histopathological observations were conducted 2, 4 and 12 weeks after surgery. Compared with the control group, the groups implanted with the complex displayed enhanced maintenance and stability of granules, suppression of epithelial downgrowth, and acceleration of new bone and cementum formation. These results indicate that the implant method using an atelocollagen-coated artificial bone implant material would be useful for periodontal surgical treatment, eliminating some of the disadvantages of conventional implant methods.

  19. A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth gaps.

    Science.gov (United States)

    Gahlert, Michael; Kniha, Heinz; Weingart, Dieter; Schild, Sabine; Gellrich, Nils-Claudius; Bormann, Kai-Hendrik

    2016-12-01

    Dental implants have traditionally been made from titanium or its alloys, but recently full-ceramic implants have been developed with comparable osseointegration properties and functional strength properties to titanium. These ceramic implants may have advantages in certain patients and situations, for example, where esthetic outcomes are particularly important. The objective of this investigation was to evaluate the performance of a newly developed full-ceramic ZrO2 monotype implant design (PURE Ceramic Implant; Institut Straumann AG, Basel, Switzerland) in single-tooth gaps in the maxilla and mandible. This was a prospective, open-label, single-arm study in patients requiring implant rehabilitation in single-tooth gaps. Full-ceramic implants were placed, with provisional and final prostheses inserted after 3 and 6 months, respectively. Crestal bone level was measured at implant placement and after 6 and 12 months. Implant survival and success were evaluated after 6 and 12 months. Further evaluations are planned after 24 and 36 months. Forty-six patients were screened for potential study participation, of whom 44 (17 men and 27 women, mean age 48 ± 14 years) were recruited into the study. The majority of implants (90.9%) were placed in the maxilla. The implant survival and implant success rate after 12 months were 97.6%. A minor change of the mean bone level occurred between implant loading (final prosthesis insertion after 6 months) and 12 months (-0.14 mm) after initial bone remodeling was observed between implant placement and loading (-0.88 mm). The results indicated that monotype ceramic implants can achieve clinical outcomes comparable to published outcomes of equivalent titanium implants. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Electrical Activation Studies of Ion Implanted Gallium Nitride

    Science.gov (United States)

    2001-11-20

    Amplifier Electromagnet Controller Lakeshore DRC -91CA Temperature Controller 706 Scanner 196 Digital Multimeter 220 Current Source 617 Electrometer...complete list of publications resulting from this doctoral research. The list is divided into three sections: journal articles, refereed conference...2001. Refereed Conference Proceedings: “Optical Characterization of Mg- and Si-Implanted GaN,” Fellows J., Yeo Y.K., Hengehold R., and Krasnobaev

  1. Implant-supported single-tooth restorations. A 12-year prospective study.

    Science.gov (United States)

    Donati, Mauro; Ekestubbe, Annika; Lindhe, Jan; Wennström, Jan L

    2016-10-01

    The aim of this study was to evaluate prospectively the 12-year outcome of implant-supported single-tooth restorations. Originally 45 self-tapping Astra Tech TiOblast(®) ST-implants were installed by a two-stage protocol in 40 subjects requiring single-tooth prosthetic replacement for a missing tooth. Clinical and radiologic examinations were performed at completion of the prosthetic treatment 4-7 months after implant installation surgery and after 5 and 12 years in function. At 12 years 31 patients and 35 implants were available for evaluation. The overall failure rate after 12 years was 10.3% on the subject level and 9.1% on the implant level. The mean bone loss amounted to 0.67 mm (SD 2.20) on a subject level and 0.47 mm (1.72) on an implant level. Three subjects (10%) and three implants (8.6%) were diagnosed with peri-implantitis. Five subjects had experienced technical complications; three incidences of loosening of the abutment retention screw during the first 5 years and two minor porcelain fracture of the crown (two patients) between 5- and 12-years of follow-up. The findings reported in this 12-year prospective case series suggest that the use of the Astra Tech dental implants may be a valid treatment alternative for single-tooth replacement prostheses. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Morphogenesis of the peri-implant mucosa: an experimental study in dogs.

    Science.gov (United States)

    Berglundh, Tord; Abrahamsson, Ingemar; Welander, Maria; Lang, Niklaus P; Lindhe, Jan

    2007-02-01

    The objective of the present experiment was to study the morphogenesis of the mucosal attachment to implants made of c.p. titanium. All mandibular premolars were extracted in 20 Labrador dogs. After a healing period of 3 months, four implants (ITI Dental Implant System) were placed in the right and left sides of the mandible. A non-submerged implant installation technique was used and the mucosal tissues were secured to the conical marginal portion of the implants with interrupted sutures. The sutures were removed after 2 weeks and a plaque control program including daily cleaning of the remaining teeth and the implants was initiated. The animals were sacrificed and biopsies were obtained at various intervals to provide healing periods extending from Day 0 (2 h) to 12 weeks. The mandibles were removed and placed in the fixative. The implant sites were dissected using a diamond saw and processed for histological analysis. Large numbers of neutrophils infiltrated and degraded the coagulum that occupied the compartment between the mucosa and the implant during the initial phase of healing. At 2 weeks after surgery, fibroblasts were the dominating cell population in the connective tissue interface but at 4 weeks the density of fibroblasts had decreased. Furthermore, the first signs of epithelial proliferation were observed in specimens representing 1-2 weeks of healing and a mature barrier epithelium occurred after 6-8 weeks of healing. The collagen fibers of the mucosa were organized after 4-6 weeks of healing. It is suggested that the soft-tissue attachment to implants placed using a non-submerged installation procedure is properly established after several weeks following surgery.

  3. Microrobotized blasting improves the bone-to-textured implant response. A preclinical in vivo biomechanical study.

    Science.gov (United States)

    Coelho, Paulo G; Gil, Luiz F; Neiva, Rodrigo; Jimbo, Ryo; Tovar, Nick; Lilin, Thomas; Bonfante, Estevam A

    2016-03-01

    This study evaluated the effect of microrobotized blasting of titanium endosteal implants relative to their manually blasted counterparts. Two different implant systems were utilized presenting two different implant surfaces. Control surfaces (Manual) were fabricated by manually grit blasting the implant surfaces while experimental surfaces (Microblasted) were fabricated through a microrobotized system that provided a one pass grit blasting routine. Both surfaces were created with the same ~50µm average particle size alumina powder at ~310KPa. Surfaces were then etched with 37% HCl for 20min, washed, and packaged through standard industry procedures. The surfaces were characterized through scanning electron microscopy (SEM) and optical interferometry, and were then placed in a beagle dog radius model remaining in vivo for 3 and 6 weeks. The implant removal torque was recorded and statistical analysis evaluated implant system and surface type torque levels as a function of time in vivo. Histologic sections were qualitatively evaluated for tissue response. Electron microscopy depicted textured surfaces for both manual and microblasted surfaces. Optical interferometry showed significantly higher Sa, Sq, values for the microblasted surface and no significant difference for Sds and Sdr values between surfaces. In vivo results depicted that statistically significant gains in biomechanical fixation were obtained for both implant systems tested at 6 weeks in vivo, while only one system presented significant biomechanical gain at 3 weeks. Histologic sections showed qualitative higher amounts of new bone forming around microblasted implants relative to the manually blasted group. Microrobotized blasting resulted in higher biomechanical fixation of endosteal dental implants and should be considered as an alternative for impant surface manufacturing.

  4. High resolution Laplace DLTS studies of defects in ion-implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Evans-Freeman, J.H. E-mail: j.evans-freeman@umist.ac.uk; Abdelgader, N.; Kan, P.Y.Y.; Peaker, A.R

    2002-01-01

    We have used high resolution Laplace deep level transient spectroscopy (LDLTS) to investigate defects in n-type silicon caused by implantation of Si, Ge or Er with doses of the order of 1x10{sup 9} cm{sup -2}. These are compared with defects created in proton irradiated n-type silicon. Unlike the simple proton irradiated case, LDLTS spectra of ion implanted silicon show that there are many emission rates associated with defects with energies in the region of E{sub c}-400 meV. We have carried out annealing studies and Laplace DLTS depth profiling and show that the complex spectra measured from a region less than half way through the implant simplify as the profile is moved through the implant and towards the tail. Annealing studies show that these defects survive an anneal that should remove the E-centre.

  5. Cochlear Implantation through the Middle Fossa Approach: A Review of Related Temporal Bone Studies and Reported Cases.

    Science.gov (United States)

    Lesser, Juan Carlos Cisneros; Brito Neto, Rubens Vuono de; Martins, Graziela de Souza Queiroz; Bento, Ricardo Ferreira

    2017-01-01

    Introduction Middle fossa approach has been suggested as an alternative for patients in whom other routes of electrode insertion are contraindicated. Even though there are temporal bone studies about the feasibility of introducing the cochlear implant through the middle fossa, until now, very few studies have described results when cochlear implant surgery is done through this approach. Objective The objective of this study is to review a series of temporal bone studies related to cochlear implantation through the middle fossa and the results obtained by different surgical groups after cochlear implantation through this approach. Data Sources PubMed, MD consult and Ovid-SP databases. Data Synthesis A total of 8 human cadaveric temporal bone studies and 6 studies reporting cochlear implant surgery through the middle fossa approach met the inclusion criteria. Temporal bone studies show that it is feasible to perform cochlear implantation through this route. So far, only two surgical groups have performed cochlear implantation through the middle fossa with a total of 15 implanted patients. One group entered the cochlea in the most upper part of the basal turn, inserting the implant in the direction of the middle and apical turns; meanwhile, the other group inserted the implant in the apical turn directed in a retrograde fashion to the middle and basal turns. Results obtained in both groups were similar. Conclusions The middle fossa approach is a good alternative for cochlear implantation when other routes of electrode insertion are contraindicated.

  6. Model Organisms Fact Sheet: Using Model Organisms to Study Health and Disease

    Science.gov (United States)

    ... Model Organisms to Study Health and Disease Using Model Organisms to Study Health and Disease Tagline (Optional) ... and treating disease in humans. What is a model? The word model has many meanings, but in ...

  7. Pilot Study of Association of Bacteria on Breast Implants with Capsular Contracture▿

    Science.gov (United States)

    Del Pozo, Jose L.; Tran, Nho V.; Petty, Paul M.; Johnson, Craig H.; Walsh, Molly F.; Bite, Uldis; Clay, Ricky P.; Mandrekar, Jayawant N.; Piper, Kerryl E.; Steckelberg, James M.; Patel, Robin

    2009-01-01

    Capsular contracture is the most common and frustrating complication in women who have undergone breast implantation. Its cause and, accordingly, treatment and prevention remain to be elucidated fully. The aim of this prospective observational pilot study was to test the hypothesis that the presence of bacteria on breast implants is associated with capsular contracture. We prospectively studied consecutive patients who underwent breast implant removal for reasons other than overt infection at the Mayo Clinic from February through September 2008. Removed breast implants were processed using a vortexing/sonication procedure and then subjected to semiquantitative culture. Twenty-seven of the 45 implants collected were removed due to significant capsular contracture, among which 9 (33%) had ≥20 CFU bacteria/10 ml sonicate fluid; 18 were removed for reasons other than significant capsular contracture, among which 1 (5%) had ≥20 CFU/10 ml sonicate fluid (P = 0.034). Propionibacterium species, coagulase-negative staphylococci, and Corynebacterium species were the microorganisms isolated. The results of this study demonstrate that there is a significant association between capsular contracture and the presence of bacteria on the implant. The role of these bacteria in the pathogenesis of capsular contracture deserves further study. PMID:19261794

  8. Coating titanium implants with bioglass and with hydroxyapatite : A comparative study in sheep

    OpenAIRE

    Lopez-Sastre, A.; Gonzalo-Orden, J.M.; Altónaga, J. A. R.; Altónaga, J. R.; Orden, M. A.

    1998-01-01

    This study compares the osteointegration of titanium implants coated with bioglass (Biovetro GSB formula) and with hydroxyapatite (HAP). Twenty-four bioglass-coated and 24 HAP-coated cylinders were implanted in the femoral diaphyses of sheep, and examined after 2, 4, 6, 8, 12, and 16 weeks. The HAP coating gave a stronger and earlier fixation to the bone than did bioglass. Bioglass formed a tissue interface which showed a macrophage reaction with little new bone formation activity. In contras...

  9. Influence of splinting materials (auto vs. photopolymerizing) on implant impression accuracy: an in vitro study

    OpenAIRE

    Braz, Luís Miguel Baptista

    2016-01-01

    Tese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2016 Purpose: The aim of the present study was to evaluate if there was any significant difference in accuracy between multiple-unit dental implant casts obtained from splinted direct impression techniques using 2 splinting materials by comparing the casts to the reference models. The null hypothesis tested was that the accuracy of implant-impressions was not affected regardless of the splinting ma...

  10. Luminescence studies on green emitting InGaN/GaN MQWs implanted with nitrogen

    OpenAIRE

    2015-01-01

    We studied the optical properties of metalorganic chemical vapour deposited (MOCVD) InGaN/GaN multiple quantum wells (MQW) subjected to nitrogen (N) implantation and post-growth annealing treatments. The optical characterization was carried out by means of temperature and excitation density-dependent steady state photoluminescence (PL) spectroscopy, supplemented by room temperature PL excitation (PLE) and PL lifetime (PLL) measurements. The as-grown and as-implanted samples were found to exhi...

  11. Direction-dependent RBS channelling studies in ion implanted LiNbO3

    Science.gov (United States)

    Wendler, E.; Becker, G.; Rensberg, J.; Schmidt, E.; Wolf, S.; Wesch, W.

    2016-07-01

    Damage formation in ion implanted LiNbO3 was studied by Rutherford backscattering spectrometry (RBS) along various directions of the LiNbO3 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 LiNbO3 lattice structure and most likely also form NbLi antisite defects.

  12. 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.

  13. Sensory innervation around immediately vs. delayed loaded implants:a pilot study

    Institute of Scientific and Technical Information of China (English)

    Yan Huang; Jeroen van Dessel; Wendy Martens; Ivo Lambrichts; Wei-Jian Zhong; Guo-Wu Ma; Dan Lin; Xin Liang; Reinhilde Jacobs

    2015-01-01

    Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks (third maxillary incisor, third and fourth mandibular premolar):immediate implant placement and immediate loading (IIP1IL);delayed implant placement and delayed loading (DIP1DL);delayed implant placement and immediate loading (DIP1IL);and natural extraction socket healing (control). Histomorphometry was performed in the peri-implant bone and soft tissues within 300 mm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP1IL showed a higher innervation (in N?mm22, 5.9461.12 vs. 3.1560.63, P,0.001) and smaller fibre diameter (in mm, 1.3760.05 vs. 1.6460.13, P50.016), smaller axon diameter (in mm, 0.8960.05 vs. 1.2460.10, P50.009) and g-ratio (0.6460.04 vs. 0.7660.05, P,0.001) in the middle region around the implants. Compared with DIP1IL in the mandible, IIP1IL had a higher nerve density (in N?mm22, 13.2362.54 vs. 9.6461.86, P50.027), greater fibre diameter (in mm, 1.3260.02 vs. 1.2060.04, P50.021), greater axon diameter (in mm, 0.9260.01 vs. 0.8960.03, P50.035) and lower g-ratio (0.6960.01 vs. 0.7460.01, P50.033) in the apical region around the implants. It may be assumed that the treatment protocol with IIP1IL is the preferred method to allow optimized peri-implant re

  14. Outcome of surgical treatment of peri-implantitis: results from a 2-year prospective clinical study in humans.

    Science.gov (United States)

    Serino, Giovanni; Turri, Alberto

    2011-11-01

    The aim of the present study was to evaluate the outcome of a surgical procedure based on pocket elimination and bone re-contouring for the treatment of peri-implantitis. The 31 subjects involved in this study presented clinical signs of peri-implantitis at one or more dental implants (i.e. ≥6 mm pockets, bleeding on probing and/or suppuration and radiographic evidence of ≥2 mm bone loss). The patients were treated with a surgical procedure based on pocket elimination and bone re-contouring and plaque control before and following the surgery. At the time of surgery, the amount of bone loss at implants was recorded. Two years following treatment, 15 (48%) subjects had no signs of peri-implant disease; 24 patients (77%) had no implants with a probing pocket depth of ≥6 mm associated with bleeding and/or suppuration following probing. A total of 36 implants (42%) out of the 86 with initial diagnosis of peri-implantitis presented peri-implant disease despite treatment. The proportion of implants that became healthy following treatment was higher for those with minor initial bone loss (2-4 mm bone loss as assessed during surgery) compared with the implants with a bone loss of ≥5 mm (74% vs. 40%). Among the 18 implants with bone loss of ≥7 mm, seven were extracted. Between the 6-month and the 2-year examination, healthy implants following treatment tended to remain stable, while deepening of pockets was observed for those implants with residual pockets. The results of this study indicated that a surgical procedure based on pocket elimination and bone re-contouring and plaque control before and following surgery was an effective therapy for treatment of peri-implantitis for the majority of subjects and implants. However, complete disease resolution at the site level seems to depend on the initial bone loss at implants. Implants with no signs of peri-implantitis following treatment tended to remain healthy during the 2-year period, while a tendency for disease

  15. Dental Implants and General Dental Practitioners of Nepal: A study of existing knowledge and need for further education

    Directory of Open Access Journals (Sweden)

    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.

  16. The Six Remaining Facts: Social Studies Content Knowledge and Elementary Preservice Teachers

    Science.gov (United States)

    Sanchez, Rebecca M.

    2010-01-01

    This article explores and examines the social studies content knowledge that preservice teachers have about commonly studies historical figures. The data indicate that preservice teachers often have shallow and decontextualized understandings of historical individuals such as Christopher Columbus and Helen Keller, despite their being repeatedly…

  17. Anchorage of titanium implants with different surface characteristics: an experimental study in rabbits

    DEFF Research Database (Denmark)

    Gotfredsen, K; Berglundh, T; Lindhe, J

    2000-01-01

    ) TiO2-blasted with particles of grain size 10 to 53 microns; (3) TiO2-blasted, grain size 63 to 90 microns; (4) TiO2-blasted, grain size 90 to 125 microns; (5) titanium plasma-sprayed (TPS). The surface topography was determined by the use of an optical instrument. Twelve rabbits, divided into two...... in group B were 9 and 12 weeks. The tibiae were removed, and each implant site was dissected, fixed, and embedded in light-curing resin. Ground sections were made, and the peri-implant bone was analyzed using fluorescence and light microscopy. RESULTS: The turned implants had the lowest Sa and Sy values......: The present study demonstrated that a clear relation exists between surface roughness, described in Sa values, and implant anchorage assessed by RMT measurements. The anchorage appeared to increase with the maturation of bone tissue during healing....

  18. Aesthetic perception of single implants placed in the anterior zone. A cross-sectional study

    Science.gov (United States)

    Burgueño-Barris, Genís; Cortés-Acha, Berta; Valmaseda-Castellón, Eduard

    2016-01-01

    Background Several aesthetic indexes have been described to assess implant aesthetics. The aim of this study was to compare the aesthetic assessment made by dental professionals and students of single-tooth implants placed in the upper incisors. Material and Methods A cross-sectional survey study using a subjective questionnaire to assess the aesthetics in 3 implant supported single-tooth cases in the anterior maxilla was performed. The interviewed subjects were divided into 4 groups: dentists with experience in implant treatment, dentists without experience in implants and 3rd and 5th year dental students. The questionnaire consisted of 2 visual analogue scales (VAS) to evaluate aesthetics, the pink esthetic score (PES), the white esthetic score (WES) and the simplified papilla index (PI). Results One-hundred dentists and one-hundred dental students filled the aesthetic assessment questionnaire. The results showed that the subjects were more critical than reference values, specially concerning prosthetic issues. The differences between groups were more obvious in the case with the best result. On the other hand, few differences were detected in the remaining cases. Regarding soft tissue and crown features, experienced dentists in implant dentistry were the most demanding. Cronbach’s Alpha showed values ≥ 0,8 in the questionnaire in every case, which indicates an adequate reliability. Conclusions Dentists and dental students have different opinions when assessing aesthetics of single tooth implant supported cases. Experience and area of expertise seem to influence the evaluation of aesthetics in the anterior region. Key words:Dental implant, anterior area, aesthetics. PMID:27031072

  19. 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.

  20. Cochlear implantation in patients with inner ear bone malformations with posterior labyrinth involvement: an exploratory study.

    Science.gov (United States)

    Palomeque Vera, Juan Miguel; Platero Sánchez-Escribano, María; Gómez Hervás, Javier; Fernández Prada, María; González Ramírez, Amanda Rocío; Sainz Quevedo, Manuel

    2016-04-01

    Inner ear bone malformations are one cause of profound sensorineural hearing loss. This investigation focused on those affecting the posterior labyrinth, especially enlarged vestibular aqueduct syndrome, which is associated with fluctuating and progressive hearing loss. The objectives of this study were to analyze the behavior of the electrical stimulation, auditory functionality and linguistic development in patients with inner ear malformations involving the posterior labyrinth. The study included ten patients undergoing cochlear implantation (cases: five with enlarged vestibular aqueduct, two with vestibular aqueduct stenosis/aplasia, and three with semicircular canal disorders). Post-implantation, data were gathered on the electrical stimulation threshold and maximum comfort levels and on the number of functioning electrodes. Evaluation of Auditory Responses to Speech (EARS) subtests were used to assess auditory functionality and language acquisition at 6, 12, and 24 months post-implantation. Results were compared with findings in a control group of 28 cochlear implantation patients without these malformations. No significant differences were found between case and control groups in electrical stimulation parameters; auditory functionality subtest scores were lower in cases than controls, although the difference was only statistically significant for some subtests. In conclusion, cochlear implantation patients with posterior labyrinth bone malformations and profound hearing loss, including those with enlarged vestibular aqueduct syndrome, showed no significant difference in electrical stimulation threshold with controls. Although some auditory functionality test results were lower in cases than in controls, cochlear implantation appears to be beneficial for all patients with these malformations.

  1. Study on surgical approaches and electrode implantation of oculomotor nerve and inferior obliquus in beagle dogs.

    Science.gov (United States)

    Zhu, Ning-Xi; Meng, You-Qiang; Feng, Bao-Hui; Wang, Xu-Hui; Li, Xin-Yuan; Yang, Min; Zhu, Shu-Gan; Li, Shi-Ting

    2009-03-01

    To study the surgical anatomy and approaches of intracranial oculomotor nerve (OMN) and inferior obliquus (IO), and the methods of their electrode implantation in dogs. The research was performed on 30 adult beagle dogs at Shanghai Jiaotong University Medical College, Shanghai, China from November 2007 to August 2008. All animals were subjected to a right transfrontotemperal approach to intracranial OMN, a transconjunctival route to IO, and the neuro-stimulating and recording electrode implantation under general anaesthesia. The OMN was stimulated and the electromyography of IO recorded and analyzed with the Powerlab System. The security and reliability of the implanted electrodes were investigated. The surgical anatomy and approaches of both the OMN from its exit from midbrain to the entrance into cavernous sinus and the IO were described. Moreover, the implantation methods of OMN stimulating electrode and the electromyographic recording electrode of IO were displayed. The implanted electrodes were safe and reliable. Some electrophysiologic data of IO were obtained in the healthy dogs. Also, some perioperative precautions for intracranial and ophthalmic surgical procedures in dog were exhibited. The mortality rate of the dogs was 0%, and no operative complications were observed. With the data provided, these surgical approaches and the methods of electrode implantation offer a choice to construct an animal model for studying various aspects of OMN regeneration.

  2. Reliability of Radiographic Assessments of Adolescent Midshaft Clavicle Fractures by the FACTS Multicenter Study Group.

    Science.gov (United States)

    Li, Ying; Donohue, Kyna S; Robbins, Christopher B; Pennock, Andrew T; Ellis, Henry B; Nepple, Jeffrey J; Pandya, Nirav; Spence, David D; Willimon, Samuel Clifton; Heyworth, Benton E

    2017-09-01

    There is a recent trend toward increased surgical treatment of displaced midshaft clavicle fractures in adolescents. The primary purpose of this study was to evaluate the intrarater and interrater reliability of clavicle fracture classification systems and measurements of displacement, shortening, and angulation in adolescents. The secondary purpose was to compare 2 different measurement methods for fracture shortening. This study was performed by a multicenter study group conducting a prospective, comparative, observational cohort study of adolescent clavicle fractures. Eight raters evaluated 24 deidentified anteroposterior clavicle radiographs selected from patients 10-18 years of age with midshaft clavicle fractures. Two clavicle fracture classification systems were used, and 2 measurements for shortening, 1 measurement for superior-inferior displacement, and 2 measurements for fracture angulation were performed. A minimum of 2 weeks after the first round, the process was repeated. Intraclass correlation coefficients were calculated. Good to excellent intrarater and interrater agreement was achieved for the descriptive classification system of fracture displacement, direction of angulation, presence of comminution, and all continuous variables, including both measurements of shortening, superior-inferior displacement, and degrees of angulation. Moderate agreement was achieved for the Arbeitsgemeinschaft für Osteosynthesefragen classification system overall. Mean shortening by 2 different methods were significantly different from each other (P < 0.0001). Most radiographic measurements performed by investigators in a multicenter, prospective cohort study of adolescent clavicle fractures demonstrated good-to-excellent intrarater and interrater reliability. Future consensus on the most accurate and clinically appropriate measurement method for fracture shortening is critical.

  3. 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.

  4. Evaluation of implant stabilization in tubercular Spondylodiscitis: a prospective study

    Directory of Open Access Journals (Sweden)

    Sharath Kumar Maila

    2015-10-01

    Results: Mechanical failure of the implant was the most commonly encountered complication. Neurological complications included progressive neurologic deterioration, hoarseness of voice, cauda equina syndrome, foot drop. Persistent worsening of pain, DVT and pressure ulcers were the complications encountered that are not specific to a region of spine. Conclusions: Stabilization is not without complications in tubercular spine. But with strict adherence to guidelines the complications can be minimal and are not dismal. [Int J Res Med Sci 2015; 3(10.000: 2647-2653

  5. Clinical study of customized aspherical intraocular lens implants

    Institute of Scientific and Technical Information of China (English)

    Lie-Xi; Jia; Zhao-Hui; Li

    2014-01-01

    AIM:To compare if there is an improvement in visual functions with age-related cataracts between patients receiving a aspherical intraocular lens(IOL) based on corneal wavefront aberration and patients randomly assigned lenses.METHODS:A total of 124 eyes of 124 patients with age-related cataracts were placed in experimental group and a group receiving randomly assigned(RA) lenses.The experimental group was undergone Pentacam corneal spherical aberration measurement before surgery; the targeted range for residual total spherical aberration after surgery was set to 0-0.3 μm. Patients with a corneal spherical aberration <0.3 μm were implanted with a zero-spherical aberration advanced optics(AO) aspherical IOL and patients with an aberration ≥0.3 μm received a Tecnis Z9003 aspherical lens in experimental group. RA patients were randomly implanted with an AO lens or a Tecnis Z9003 lens. Three months after surgery total spherical aberration, photopic/mesopic contrast sensitivities, photopic/mesopic with glare contrast sensitivities, and logMAR vision were measured.RESULTS:Statistical analysis on logMAR vision showed no significant difference between two groups(P =0.413). The post-surgical total spherical aberration was 0.126 ±0.097 μm and 0.152 ±0.151 μm in the experimental and RA groups, respectively(P =0.12). The mesopic contrast sensitivities at spatial frequencies of 6,12 and 18 c/d in the experimental group were significantly higher than of the RA group(P =0.00; P =0.04;P =0.02). The mesopic with glare contrast sensitivity in the experimental group at a spatial frequency of 18 c/d was also significantly higher vs the RA group(P =0.01).CONCLUSION:Pre-surgical corneal spherical aberration measurement in cataract patients followed bycustomized selection of aspherical IOL implants improved mesopic contrast sensitivities at high spatial frequencies, and thus is a superior strategy compared to the random selection of aspherical intraocular lens implants.

  6. 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.

  7. Implants in fresh extraction sockets: a prospective 5-year follow-up clinical study.

    Science.gov (United States)

    Botticelli, Daniele; Renzi, Antonio; Lindhe, Jan; Berglundh, Tord

    2008-12-01

    The aim of this prospective study was to evaluate the 5-year clinical outcome of the 'immediate implants.' One week after the cementation of the prosthesis, a clinical baseline examination was carried out. Clinical measurements were performed of the following: plaque, mucositis, probing pocket depth, and soft tissue position. The height of the keratinized mucosa was measured at the buccal/lingual aspects. Standardized intra-oral radiographs were taken. The marginal level of bone to implant contact [radiographic (Rx) bone level] was measured, and Rx bone level change over time was evaluated. The clinical/radiographic measurements were repeated on a yearly basis. The subjects were enrolled in a carefully supervised oral hygiene program. It was demonstrated that 'immediate implants' that were loaded after 5-7 months had a high success rate. During the 5-year interval, no implant was lost, and the mean Rx bone level at the implants was maintained or even improved. The plaque and mucositis scores were low (<20%) at baseline and at all re-examinations. Implant sites located adjacent to the teeth showed bone gain during the initial period while sites that were facing edentulous zones lost some bone.

  8. Study of hydrogen implantation-induced blistering in GaSb for potential layer transfer applications

    Science.gov (United States)

    Pathak, Ravi; Dadwal, U.; Singh, R.

    2017-07-01

    GaSb samples were implanted by 100 keV hydrogen ions (H+) at room temperature with fluence values of 1  ×  1017 and 2  ×  1017 ions cm-2. Post-implantation annealing studies revealed that the samples implanted with a fluence of 2  ×  1017 ions cm-2 did not show blistering/exfoliation. For the lower fluence, the samples showed the formation of surface blisters/craters along with the large area exfoliation of the top H-implanted surface. Topographical investigations of the samples were carried out using Nomarski optical microscopy, atomic force microscopy and stylus surface profilometry. The lateral sizes and heights of the blisters varied between 2-5 µm and 5-20 nm respectively. The root mean square roughness of the exfoliated region was about 12 nm while the exfoliation depth was found to be 730 nm. The exfoliation depth in the H-implanted GaSb is close to the damage concentration peak as found from SRIM calculations. The Föppl-von Karman theory of thin plates has been used to understand the effect of internal pressure and stress on the surface blistering. Using the above mentioned implantation and annealing parameters, potential layer transfer of GaSb could be enabled.

  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. Surface morphology analysis of dental implants following insertion into bone using scanning electron microscopy: a pilot study.

    Science.gov (United States)

    Deppe, Herbert; Grünberg, Christina; Thomas, Mücke; Sculean, Anton; Benner, Klaus-Ulrich; Bauer, Florian J M

    2015-11-01

    Dental implants have become essential in reconstructive dentistry. Primary healing is determined by the design of their surface. The aim of this pilot study has been to investigate whether the morphology of the sandblasted and acid-etched (SLA(®) ) surface remains unaffected after the insertion process into human bone. Two edentulous-atrophied human jaw specimens were used. Six brand new Straumann Standard RN implants with an SLA(®) surface and having a diameter of 3.3 mm and a length of 12 mm were inserted. Another two implants of the same type, but not inserted into bone, served as a reference. After explantation, the four implants were cleaned in an ultrasonic bath and two were left uncleaned. All eight implants were inspected by SEM for qualitative surface changes. All four implants showed relevant changes of the topography at the apical thread flanks. The non-cleaned implants showed an almost complete coverage of the surface by a honeycomb-like structure, consistent with bone residues. The reference implants showed no changes. The results indicate that, for the osseointegration of dental implants, subtractive modifications of implant surfaces are less important than the reestablishment of the destroyed TiO2 layer. Further studies of other implant surfaces are required to verify the present results. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. 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.

  12. Fact or factitious? A psychobiological study of authentic and simulated dissociative identity states.

    Directory of Open Access Journals (Sweden)

    A A T S Reinders

    Full Text Available BACKGROUND: Dissociative identity disorder (DID is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. METHODOLOGY/PRINCIPAL FINDINGS: DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related in an autobiographical memory script-driven (neutral or trauma-related imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. CONCLUSIONS/SIGNIFICANCE: The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic origin.

  13. Fact or Factitious? A Psychobiological Study of Authentic and Simulated Dissociative Identity States

    Science.gov (United States)

    Simone Reinders, A. A. T.; Willemsen, Antoon T. M.; Vos, Herry P. J.; den Boer, Johan A.; Nijenhuis, Ellert R. S.

    2012-01-01

    Background Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. Methodology/Principal Findings DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related) in an autobiographical memory script-driven (neutral or trauma-related) imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. Conclusions/Significance The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic) origin. PMID:22768068

  14. Fact or fiction? A longitudinal study of play and the development of reflective functioning.

    Science.gov (United States)

    Tessier, V P; Normandin, L; Ensink, K; Fonagy, P

    2016-01-01

    In Fonagy and Target's (1996, 2000) developmental model of mentalization, play is theorized as a precursor of later mentalization and reflective function (RF); however, the relationship between play and later mentalization and RF has yet to be empirically tested. These processes are particularly important in the context of trauma, but an empirical model of the relationships among mentalization, play, and trauma is currently lacking. The aim of this longitudinal study was to examine whether children's capacity to engage in pretend play, to symbolize, and to make play narratives was associated with later RF in those children. Thirty-nine sexually abused children and 21 nonabused children (aged 3 to 8) participated in the study. The Children's Play Therapy Instrument was used to assess children's free play. Three years after the play assessment, children's RF was assessed using the Child Attachment Interview, coded with the Child and Adolescent Reflective Functioning Scale. Pretend play completion was associated with later other-understanding. Play was also found to mediate the relationship between sexual abuse and children's later mentalization regarding others. These findings are consistent with Fonagy and Target's emphasis on the role of pretend play in the development of a nuanced sense of the qualities of the mind and reality. In sum, the findings lend support to Fonagy and Target's account of playing with reality, and the development of mentalization suggests that it may be more than "fiction." Furthermore, these results suggest that children's ability to create meaningful and coherent play sequences after sexual abuse is associated with the development of a better understanding of their relationships with others. Clinical implications and future directions are discussed.

  15. In vivo tissue distribution and efficacy studies for cyclosporin A loaded nano-decorated subconjunctival implants.

    Science.gov (United States)

    Yavuz, Burçin; Bozdağ Pehlivan, Sibel; Kaffashi, Abbas; Çalamak, Semih; Ulubayram, Kezban; Palaska, Erhan; Çakmak, Hasan Basri; Ünlü, Nurşen

    2016-11-01

    Biodegradable implants are promising drug delivery systems for sustained release ocular drug delivery with the benefits such as minimum systemic side effects, constant drug concentration at the target site and getting cleared without surgical removal. Dry eye syndrome (DES) is a common disease characterized with the changes in ocular epithelia surface and results in inflammatory reaction that might lead to blindness. Cyclosporin A (CsA) is a cyclic peptide that is frequently employed for the treatment of DES and it needs to be applied several times a day in tear drops form. The aim of this study was to evaluate in vivo behavior and efficacy of the developed nano-decorated subconjunctival implant systems for sustained release CsA delivery. Biodegradable Poly-ɛ-caprolactone (PCL) implant or micro-fiber implants containing CsA loaded poly-lactide-co-glycolide (85:15) (PLGA) or PCL nanoparticles were prepared in order to achieve sustained release. Two of the formulations PCL-PLGA-NP-F and PCL-PCL-NP-I were selected for in vivo evaluation based on their in vitro characteristics determined in our previous study. In this study, formulations were implanted to Swiss Albino mice with induced dry eye syndrome to investigate the ocular distribution of CsA following subconjunctival implantation and to evaluate the efficacy. Tissue distribution study indicated that CsA was present in ocular tissues such as cornea, sclera and lens even 90 days after the application and blood CsA levels were found lower than ocular tissues. Efficacy studies also showed that application of CsA-loaded fiber implant formulation resulted in faster recovery based on their staining scores.

  16. 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

  17. Building America Case Study: Boiler Control Replacement for Hydronically Heated Multifamily Buildings, Cambridge, Massachusetts (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-11-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency. Efficient operation of the heating system faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68 degrees F) than day (73 degrees F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.

  18. Poor social integration and suicide: fact or artifact? A case-control study.

    Science.gov (United States)

    Duberstein, P R; Conwell, Y; Conner, K R; Eberly, S; Evinger, J S; Caine, E D

    2004-10-01

    Sociological studies have shown that poor social integration confers suicide risk. It is not known whether poor integration amplifies risk after adjusting statistically for the effects of mental disorders and employment status. A case-control design was used to compare 86 suicides and 86 living controls 50 years of age and older, matched on age, gender, race, and county of residence. Structured interviews were conducted with proxy respondents for suicides and controls. Social integration was defined in reference to two broad levels of analysis: family (e.g. sibship status, childrearing status) and social/ community (e.g. social interaction, religious participation, community involvement). Bivariate analyses showed that suicides were less likely to be married, have children, or live with family. They were less likely to engage in religious practice or community activities and they had lower levels of social interaction. A trimmed logistic regression model showed that marital status, social interaction and religious involvement were all associated with suicide even after statistical adjusting for the effects of affective disorder and employment status. Adding substance abuse to the model eliminated the effects of religious involvement. The association between family and social/community indicators of poor social integration and suicide is robust and largely independent of the presence of mental disorders. Findings could be used to enhance screening instruments and identify problem behaviors, such as low levels of social interaction, which could be targeted for intervention.

  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.

    Directory of Open Access Journals (Sweden)

    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. Facts about Cataract

    Science.gov (United States)

    ... Home > Eye Health Information > Cataract > Facts About Cataract Facts About Cataract This information was developed by the ... citizen to get this type of cataract. In fact, people can have an age-related cataract in ...

  1. Facts About Pink Eye

    Science.gov (United States)

    ... Information > Pink Eye (Conjunctivitis) > Facts About Pink Eye Facts About Pink Eye Pink eye is one of ... for preventing eye infections. Last Reviewed: November 2015 Fact Sheet Blurb The National Eye Institute (NEI) is ...

  2. Facts about Folic Acid

    Science.gov (United States)

    ... Partners About Us Information For… Media Policy Makers Facts About Folic Acid Language: English (US) Español ( ... a woman needs 400 micrograms (mcg) every day. Facts About Folic Acid Download and print this fact ...

  3. Stress analysis in platform-switching implants: a 3-dimensional finite element study.

    Science.gov (United States)

    Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; Falcón-Antenucci, Rosse Mary; Júnior, Joel Ferreira Santiago; de Carvalho, Paulo Sérgio Perri; de Moraes, Sandra Lúcia Dantas; Noritomi, Pedro Yoshito

    2012-10-01

    The aim of this study was to evaluate the influence of the platform-switching technique on stress distribution in implant, abutment, and peri-implant tissues, through a 3-dimensional finite element study. Three 3-dimensional mandibular models were fabricated using the SolidWorks 2006 and InVesalius software. Each model was composed of a bone block with one implant 10 mm long and of different diameters (3.75 and 5.00 mm). The UCLA abutments also ranged in diameter from 5.00 mm to 4.1 mm. After obtaining the geometries, the models were transferred to the software FEMAP 10.0 for pre- and postprocessing of finite elements to generate the mesh, loading, and boundary conditions. A total load of 200 N was applied in axial (0°), oblique (45°), and lateral (90°) directions. The models were solved by the software NeiNastran 9.0 and transferred to the software FEMAP 10.0 to obtain the results that were visualized through von Mises and maximum principal stress maps. Model A (implants with 3.75 mm/abutment with 4.1 mm) exhibited the highest area of stress concentration with all loadings (axial, oblique, and lateral) for the implant and the abutment. All models presented the stress areas at the abutment level and at the implant/abutment interface. Models B (implant with 5.0 mm/abutment with 5.0 mm) and C (implant with 5.0 mm/abutment with 4.1 mm) presented minor areas of stress concentration and similar distribution pattern. For the cortical bone, low stress concentration was observed in the peri-implant region for models B and C in comparison to model A. The trabecular bone exhibited low stress that was well distributed in models B and C. Model A presented the highest stress concentration. Model B exhibited better stress distribution. There was no significant difference between the large-diameter implants (models B and C).

  4. Biomechanical study of the bone tissue with dental implants interaction

    Directory of Open Access Journals (Sweden)

    Navrátil P.

    2011-12-01

    Full Text Available The article deals with the stress-strain analysis of human mandible in the physiological state and after the dental implant application. The evaluation is focused on assessing of the cancellous bone tissue modeling-level. Three cancellous bone model-types are assessed: Non-trabecular model with homogenous isotropic material, nontrabecular model with inhomogeneous material obtained from computer tomography data using CT Data Analysis software, and trabecular model built from mandible section image. Computational modeling was chosen as the most suitable solution method and the solution on two-dimensional level was carried out. The results show that strain is more preferable value than stress in case of evaluation of mechanical response in cancellous bone. The non-trabecular model with CT-obtained material model is not acceptable for stress-strain analysis of the cancellous bone for singularities occurring on interfaces of regions with different values of modulus of elasticity.

  5. Feasibility study for future implantable neural-silicon interface devices.

    Science.gov (United States)

    Al-Armaghany, Allann; Yu, Bo; Mak, Terrence; Tong, Kin-Fai; Sun, Yihe

    2011-01-01

    The emerging neural-silicon interface devices bridge nerve systems with artificial systems and play a key role in neuro-prostheses and neuro-rehabilitation applications. Integrating neural signal collection, processing and transmission on a single device will make clinical applications more practical and feasible. This paper focuses on the wireless antenna part and real-time neural signal analysis part of implantable brain-machine interface (BMI) devices. We propose to use millimeter-wave for wireless connections between different areas of a brain. Various antenna, including microstrip patch, monopole antenna and substrate integrated waveguide antenna are considered for the intra-cortical proximity communication. A Hebbian eigenfilter based method is proposed for multi-channel neuronal spike sorting. Folding and parallel design techniques are employed to explore various structures and make a trade-off between area and power consumption. Field programmable logic arrays (FPGAs) are used to evaluate various structures.

  6. A Study of Implanted and Wearable Body Sensor Networks

    CERN Document Server

    Ullah, Sana; Siddiqui, M Arif; Kwak, Kyung Sup; 10.1007/978-3-540-78582-8_47

    2009-01-01

    Recent advances in intelligent sensors, microelectronics and integrated circuit, system-on-chip design and low power wireless communication introduced the development of miniaturised and autonomous sensor nodes. These tiny sensor nodes can be deployed to develop a proactive Body Sensor Network (BSN). The rapid advancement in ultra low-power RF (radio frequency) technology enables invasive and non-invasive devices to communicate with a remote station. This communication revolutionizes healthcare system by enabling long term health monitoring of a patient and providing real time feedback to the medical experts. In this paper, we present In-body and On-body communication networks with a special focus on the methodologies of wireless communication between implanted medical devices with external monitoring equipment and recent technological growth in both areas. We also discuss open issues and challenges in a BSN.

  7. The use of rapid prototyped implants to simulate knee joint abnormalities for in vitro testing: a validation study with replica implants of the native trochlea.

    Science.gov (United States)

    Van Haver, Annemieke; De Roo, Karel; De Beule, Matthieu; Van Cauter, Sofie; Labey, Luc; De Baets, Patrick; Claessens, Tom; Verdonk, Peter

    2014-08-01

    To investigate the biomechanical effect of skeletal knee joint abnormalities, the authors propose to implant pathologically shaped rapid prototyped implants in cadaver knee specimens. This new method was validated by replacing the native trochlea by a replica implant on four cadaver knees with the aid of cadaver-specific guiding instruments. The accuracy of the guiding instruments was assessed by measuring the rotational errors of the cutting planes (on average 3.01° in extension and 1.18° in external/internal rotation). During a squat and open chain simulation, the patella showed small differences in its articulation with the native trochlea and the replica trochlea, which could partially be explained by the rotational errors of the implants. This study concludes that this method is valid to investigate the effect of knee joint abnormalities with a replica implant as a control condition to account for the influence of material properties and rotational errors of the implant. © IMechE 2014.

  8. Optimized Axillary Vein Technique versus Subclavian Vein Technique in Cardiovascular Implantable Electronic Device Implantation: A Randomized Controlled Study

    Institute of Scientific and Technical Information of China (English)

    Peng Liu; Yi-Feng Zhou; Peng Yang; Yan-Sha Gao; Gui-Ru Zhao; Shi-Yan Ren; Xian-Lun Li

    2016-01-01

    Background:The conventional venous access for cardiovascular implantable electronic device (CIED) is the subclavian vein,which is often accompanied by high complication rate.The aim of this study was to assess the efficacy and safety of optimized axillary vein technique.Methods:A total of 247 patients undergoing CIED implantation were included and assigned to the axillary vein group or the subclavian vein group randomly.Success rate of puncture and complications in the perioperative period and follow-ups were recorded.Results:The overall success rate (95.7% vs.96.0%) and one-time success rate (68.4% vs.66.1%) of punctures were similar between the two groups.In the subclavian vein group,pneumothorax occurred in three patients.The subclavian gaps of three patients were too tight to allow operation of the electrode lead.In contrast,there were no puncture-associated complications in the axillary vein group.In the patient follow-ups,two patients in the subclavian vein group had subclavian crush syndrome and both of them received lead replacement.The incidence of complications during the perioperative period and follow-ups of the axillary vein group and the subclavian vein group was 1.6% (2/125) and 8.2% (10/122),respectively (x2=5.813,P =0.016).Conclusion:Optimized axillary vein technique may be superior to the conventional subclavian vein technique for CIED lead placement.

  9. Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Breast Implants Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Breast implants are medical devices that are implanted under the ...

  10. Bone tissue formation adjacent to implants placed in fresh extraction sockets: an experimental study in dogs.

    Science.gov (United States)

    Botticelli, Daniele; Persson, Leif G; Lindhe, Jan; Berglundh, Tord

    2006-08-01

    To study the healing of marginal defects that occurred at implants placed in a healed ridge or in fresh extraction sockets. Six dogs were used. The right side of the mandible was used in the first part of the study. The first, second premolars and first molars were extracted. After 3 months of healing the bone was prepared for implant installation in these premolar and molar sites. The marginal 5 mm of each recipient site was widened with a conical drill. Following implant installation a gap of varying dimension occurred around the titanium rod (artificial defect (A) sites). At this interval the third and fourth premolars were extracted and implants were installed in the distal socket of the two teeth (natural defect (N) sites). The flaps were sutured to allow non-submerged healing. After 2 months, the procedures were repeated in the left side. Two months later the animals were euthanized, and biopsies were obtained and prepared for histological examination. The length of the zone of de novo'bone-to-implant contact' in the defect region was longer at the A sites than at the N sites both at the 2- and the 4-month interval. Further, while after 4 months of healing the marginal bone crest at the A sites was located close to the abutment/fixture junction, at the N sites a marked reduction of the height of the bone crest was documented. Hence, most A site defects became completely resolved whereas healing of the N site defects was incomplete. The process of bone modeling and remodeling at an implant placed in a fresh extraction socket differs from the resolution of marginal defects that may occur following implant installation in a healed ridge.

  11. 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

  12. The Impact of Force Transmission on Narrow-Body Dental Implants Made of Commercially Pure Titanium and Titanium Zirconia Alloy with a Conical Implant-Abutment Connection: An Experimental Pilot Study.

    Science.gov (United States)

    Nelson, Katja; Schmelzeisen, Rainer; Taylor, Thomas D; Zabler, Simon; Wiest, Wolfram; Fretwurst, Tobias

    2016-01-01

    The purpose of this study was to visualize the mode and impact of force transmission in narrowdiameter implants with different implant-abutment designs and material properties and to quantify the displacement of the abutment. Narrow-diameter implants from two manufacturers were examined: Astra 3.0-mm-diameter implants (Astra OsseoSpeed TX; n = 2) and Straumann Bone Level implants with a 3.3-mm diameter made of commercially pure titanium (cpTi) Gr. 4 (n = 2) and 3.3-mm TiZr-alloy (n = 2; Bone Level, Straumann) under incremental force application using synchrotron radiography (absorption and inline x-ray phase-contrast) and tomography. During loading (250 N), Astra 3.0 and Bone Level 3.3- mm implants showed a deformation of the outer implant shoulder of 61.75 to 95 μm independent of the implant body material; the inner implant diameter showed a deformation of 71.25 to 109.25 μm. A deformation of the implant shoulder persisted after the removal of the load (range, 42.75 to 104.5 μm). An angulated intrusion of the abutment (maximum, 140 μm) into the implant body during load application was demonstrated; this spatial displacement persisted after removal of the load. This study demonstrated a deformation of the implant shoulder and displacement of the abutment during load application in narrow-diameter implants.

  13. Importance of the Roughness and Residual Stresses of Dental Implants on Fatigue and Osseointegration Behavior. In Vivo Study in Rabbits.

    Science.gov (United States)

    Velasco, Eugenio; Monsalve-Guil, Loreto; Jimenez, Alvaro; Ortiz, Iván; Moreno-Muñoz, Jesús; Nuñez-Marquez, Enrique; Pegueroles, Marta; Pérez, Román A; Gil, Francisco Javier

    2016-12-01

    This study focuses on the fatigue behavior and bone-implant attachment for the more usual surfaces of the different CP-titanium dental implants. The implants studied were: as-received (CTR), acid etching (AE), spark-anodization (SA), and with a grit-blasted surface (GB). Residual stresses were determined by means of X-ray diffraction. The fatigue tests were carried out at 37°C on 160 dental implants, and the stress-failure (S-N) curve was determined. The fatigue tests showed that the grit-blasting process improved fatigue life. This is a consequence of the layer of compressive residual stresses that the treatment generates in titanium surfaces. Further, our aim was to assess and compare the short- and midterm bone regenerative potential and mechanical retention of the implants in bone of New Zealand rabbits. The mechanical retention after 4 and 10 weeks of implantation was evaluated with histometric and pull-out tests, respectively, as a measure of the osseointegration of the implants. The results demonstrated that the GB treatment produced microrough that accelerated bone tissue regeneration and increased mechanical retention in the bone bed at short periods of implantation in comparison with all other implants tested. The GB surface produced an improvement in mechanical long-time behavior and improved bone growth. These types of treated implants can have great potential in clinical applications, as evidenced by the outcomes of the current study.

  14. [Modern methods for studying the surface of titanium implants (literature review)].

    Science.gov (United States)

    Suba, Csongor; Velich, Norbert; Vörös, János; Turi, Csaba; Szabó, György

    2004-02-01

    Studies of the coatings found on the surface of titanium implants employed in oral surgery are indispensable for understanding the interactions between the organism and the implant. This paper surveys the theory and practical applicability of the methods most frequently applied to study the surface structure and composition of the material. Detailed accounts are given of various structure investigation methods: scanning electron microscopy, stereo scanning electron microscopy, X-ray diffraction, atomic force microscopy and interference microscopy; and of various composition investigation methods: secondary ion mass spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy; and also of the corrosion procedures for the study of electrochemical behaviour.

  15. Implant Stability Changes during Early Phase of Healing:A Prospective Cohort Study

    Directory of Open Access Journals (Sweden)

    A. Mesgarzadeh

    2009-06-01

    Full Text Available Objective: To assess the stability changes as a reflection of early healing around roughened-surface implants in human by resonance frequency analysis (RFA.Materials and Methods: One hundred and fifty one ITI SLA implants were placed in either maxilla or mandible of 68 patients. Bone type was classified into 4 groups according to Lekholm and Zarb index. RFA was used for direct implant stability measurement on theday of implant placement, and at 14, 30 and 60 days after placement. Student t-test and ANOVA served for statistical analysis.Results: No early failure occurred. The highest and lowest primary stability was measured in type 1 and type 4 bone, respectively. Implant stability increased over time in types 3 and 4 bone but continuously decreased in type 1 bone during the first 60 days of healing.In type 2 a small decrease in stability was observed until 30 days, and after that the stability increased. The difference between implant stability in type 2 and type 4 bone at eachtime point was highly significant (P0.05. The effect of implant length and diameter on stability at different times was tested with mixed model ANOVA, and no significant difference among groups was observed (P>0.05Conclusion: The present study demonstrated that the pattern of stability changes was different among various bone types. With regard to primary stability and pattern of stability changes in types 2 and 3 bone, immediate and early loading protocols can be recommended in these two bone types, respectively.

  16. Maxillary reconstruction to enable implant insertion: a retrospective study of 181 patients

    Directory of Open Access Journals (Sweden)

    Carneiro José Mario

    2008-12-01

    Full Text Available Abstract Background The purpose of the present study was to evaluate different types of maxillary pre-prosthetic surgery using autogenous bone graft and suggest a guideline for maxillary reconstruction to place implant. Methods 181 patients (125 females and 56 males, age range from 16 to 76 years old, were operated at the Maxillo-Facial Service of the Lille's 2 Universitary Hospital Center (Chairman Pr Joël Ferri. Different techniques were used, but always with autogenous bone grafting. 21 patients underwent a Lefort 1 procedure, 139 underwent sinus graft with or without vestibular onlay graft and 21 underwent onlay graft. This surgical procedure was made to allow the insertion of 685 implants. Results The patients were evaluated by clinical and radiological assessment. In the cases of Lefort 1, the rate of successful osteointegration was higher when the implants were placed in the second part of a two stages procedure: 92%, against 81% for one stage. In cases of sinus lift procedure, the rate of implant success was 98%. The infection rate was 3.5%. There was no significant resorption and the type of prosthesis used was a denture retained by a bar or fixed bridge. In cases of onlay graft, the implant insertion success was 97% and there was no infection. The amount of resorption was more significant in the pre-maxilla than in the other areas and the type of prosthesis used was fixed dentures. Conclusion These observations demonstrate that: the aetiology of the bone defect indicate the type and number of the surgical procedures to re-established good jaws relationship and give the bone conditions to implant insertion successful. Clinical Relevance A guideline for surgical decision in the maxillary reconstruction for oral rehabilitation by implants may help to prevent failures of osseous resorption disorders and to foresee the investment of the bone in quality and necessary quantity.

  17. Masticatory function and patient satisfaction with implant-supported mandibular overdentures: a prospective 5-year study

    DEFF Research Database (Denmark)

    Bakke, Merete; Holm, Betty; Gotfredsen, Klaus

    2002-01-01

    PURPOSE: The aim of this study was to assess the outcome of treatment with implant-supported mandibular overdentures in terms of biting and chewing, in entirely satisfied and not fully satisfied patients. MATERIALS AND METHODS: Twelve edentulous patients who had worn dentures for at least 5 years...... muscle activity, even before implant placement, than the entirely satisfied patients. CONCLUSION: Implant-supported mandibular overdenture treatment permits better biting and chewing function than conventional complete dentures.......PURPOSE: The aim of this study was to assess the outcome of treatment with implant-supported mandibular overdentures in terms of biting and chewing, in entirely satisfied and not fully satisfied patients. MATERIALS AND METHODS: Twelve edentulous patients who had worn dentures for at least 5 years...... participated. They were in good health but had retention problems with their mandibular dentures. First, all patients received new dentures. After 3 months, two Astra Tech implants were placed in the anterior part of the mandible, and 6 months later the abutments were connected. Patient assessment...

  18. STUDY OF ADVANTAGES AND DISADVANTAGES OF TOTALLY IMPLANTABLE VENOUS ACCESS DEVICE

    Directory of Open Access Journals (Sweden)

    J. Ahmadi

    2006-07-01

    Full Text Available Totally implantable venous access devices (TIVAD or implantable catheter ports are devices which can be implanted subcutaneously. They enable prolonged and repeated access to the vascular system, into the peritoneal cavity or intravertebral space. This device is particularly useful for repeated medical injection, for blood sampling or transfusion of blood and blood derivatives and for total parenteral nutrition (TPN. Although many patients benefit from the insertion of TIVAD without any secondary effects, any surgical implantation can nevertheless lead to complications. ‎In this study, we investigated the advantages and disadvantages of TIVAD catheter in pediatric age group. A total of 94 cases, 2 to 14 years old, were included in our study. We implanted TIVAD in these patients for chemotherapy in 83 cases (88.29%, for prolonged TPN in 6 cases (6.38%, for corticosteroid and antibiotic therapy after ‎Kasai operation in 2 cases (2.12%, for intermittent IV therapy in 2 cases (2.12% and for need to partial parenteral nutrition in 1 case (1.06%. Out of 94 cases, 14 cases (15% had some kind of complications and 80 cases (85% had no complication. There was no mortality. Most patients and their parents (82 cases, 87.23% were satisfied from TIVAD. ‎It seems that TIVAD can be a useful device for many chronic patients who need an IV access for multiple injections.

  19. X-ray photoelectron study of Si{sup +} ion implanted polymers

    Energy Technology Data Exchange (ETDEWEB)

    Tsvetkova, T; Balabanov, S; Bischoff, L; Krastev, V; Stefanov, P; Avramova, I, E-mail: tania_tsvetkova@yahoo.co.u

    2010-11-01

    X-ray photoelectron spectroscopy was used to characterize different polymer materials implanted with low energy Si{sup +} ions (E=30 keV, D= 1.10{sup 17} cm{sup -2}). Two kinds of polymers were studied - ultra-high-molecular-weight poly-ethylene (UHMWPE), and poly-methyl-methacrylate (PMMA). The non-implanted polymer materials show the expected variety of chemical bonds: carbon-carbon, carbon being three- and fourfold coordinated, and carbon-oxygen in the case of PMMA samples. The X-ray photoelectron and Raman spectra show that Si{sup +} ion implantation leads to the introduction of additional disorder in the polymer material. The X-ray photoelectron spectra of the implanted polymers show that, in addition to already mentioned bonds, silicon creates new bonds with the host elements - Si-C and Si-O, together with additional Si dangling bonds as revealed by the valence band study of the implanted polymer materials.

  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. 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.

  2. Hemodynamics of Stent Implantation Procedures in Coronary Bifurcations: an in vitro study

    CERN Document Server

    Brindise, Melissa C; Burzotta, Francesco; Migliavacca, Francesco; Vlachos, Pavlos P

    2016-01-01

    Stent implantation in coronary bifurcations presents unique challenges and currently there is no universally accepted stent deployment approach. Despite clinical and computational studies, to date, the effect of each stent implantation method on the coronary artery hemodynamics is not well understood. In this study the hemodynamics of stented coronary bifurcations under pulsatile flow conditions were investigated experimentally. Three implantation methods, provisional side branch (PSB), culotte (CUL), and crush (CRU), were investigated using time-resolved particle image velocimetry (PIV) to measure the velocity fields. Subsequently, hemodynamic parameters including wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time (RRT) were calculated and the pressure field through the vessel was non-invasively quantified. The effects of each stented case were evaluated and compared against an un-stented case. CRU provided the lowest compliance mismatch, but demonstrated detrimental stent in...

  3. 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.

  4. A cross-sectional study on the prevalence of marginal bone loss among implant patients.

    Science.gov (United States)

    Cecchinato, Denis; Parpaiola, Andrea; Lindhe, Jan

    2013-01-01

    The aim of the present cross-sectional retrospective study was to determine bone loss in a sample of subjects restored with implant-supported prostheses and the prevalence and severity of peri-implantitis in a sub-sample. A total of 139 patients who had attended a follow-up visit in 2007 were considered for inclusion. Subjects with implants that had been in function for less than 3 years or had poor quality radiographs were excluded. The final study population comprised 133 subjects with a total of 407 implants. Radiographic measurements identified subjects who had ≥1 implant site exhibiting marginal bone loss of >0.5 mm; 40 subjects met this criterion and were recalled for a clinical examination. Of the 40 subjects that were recalled for the clinical examination, 30 attended. The following parameters were recorded at mesial, distal, buccal, and lingual/palatal aspects of all implants: oral hygiene standard (plaque), bleeding on probing, probing pocket depth (PPD). The mean interval between the baseline (1-year post-loading) and the follow-up radiographs was 4.8 ± 2.3 years. In the total subject sample (133 subjects and 407 implants), the mean amount of marginal bone loss that had occurred was 0.2 ± 1.2 mm. Ninety-three subjects with 246 implant sites exhibited no bone level alteration (group A), whereas 40 subjects with 161 implant sites (group B) displayed marginal bone loss of >0.5 mm at ≥1 implant (loser site). Sixty-eight implant sites in group B exhibited bone loss of >0.5 mm. However, only 20% of subjects and 11% of sites had lost >1 mm marginal bone, and 8% of subjects and 4% of sites had lost >2 mm bone. The total amount of bone loss that had occurred in group B was (i) 0.88 ± 1.5 mm and (ii) among the loser sites 2.1 ± 1.4 mm. Thirty subjects from group B were exposed to a clinical examination; out of 37 sites with bone loss >0.5 mm in this subgroup, 29 sites had a PPD value of ≥4 mm. Marginal bone loss (>0.5 mm) at implants

  5. Comparative study of some metallic biomaterials used as implants

    Energy Technology Data Exchange (ETDEWEB)

    Al-Mobarak, N.A. [Chemistry Department, Girls' College of Education, Riyadh University for Girls, Riyadh (Saudi Arabia)

    2008-07-15

    The electrochemical behavior of two Ti alloys (TA and TAV) and two grades of stainless steels (SS{sub 1} and SS{sub 2}), commonly used as biomedical implant materials, particularly for orthopedic and osteosynthesis applications, was investigated in Hank's solution at 37 C and different pH. The aim was to distinguish between the behavior of these materials in artificial physiological solution through analysis of their corrosion potential variation with time and potentiodynamic polarization curves. Characterization of the modified surface layers was made by means of microscopic examinations, hardness measurements and X-ray diffraction analysis. The results indicated that in neutral Hank's solution (pH = 7.2) SS{sub 2} and SS{sub 1} samples were of higher corrosion resistance than titanium alloys. The behavior was reversed in the acidic media (pH=5.0 or 3.0), where TA had the least corrosion rate and the corrosion susceptibility increased in the order TA

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. The influence of length of implant on primary stability: An in vitro study using resonance frequency analysis

    Science.gov (United States)

    Al-dakes, Ala M.

    2017-01-01

    Background Primary stabilityis not sufficientin less contact area between the implant and bone, the healing process because will be disrupted due to micro-motions and fibrous tissue affects osseointegration. Material and Methods We implemented an in vitro experimental study of total 135 XiVE® implants were inserted in 22.5 bovine cow ribs with bone quality similar to a type IV human bone. Each rib end received a group of three different implant lengths, which were 8mm, 13mm and 15mm and had the same diameter 3.8mm. Immediately after the implant placement, its primary stability was measured using Osstell Mentor equipment. ANOVA Tukey’s honest to test the significant difference were performed for data analysis between the resonance measures of the different lengths of implants. Statistical significance was assessed at a level P< 0.05. Results A total of 45 implants were inserted for each length at cortical bone level. A significant difference between the three groups in favor of implant with 15mm length group (P = 0.000). Conclusions Increasing dental implant length is considered to play a fundamental role in increasing dental implant primary stability, even in poor bone quality, through controlling the bone preparation process. Key words:Dental implants, primary stability, resonance frequency analysis. PMID:28149455

  11. 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.

  12. Mathematical evaluation of the influence of multiple factors on implant stability quotient values in clinical practice: a retrospective study

    Science.gov (United States)

    Huang, Hairong; Wismeijer, Daniel; Shao, Xianhong; Wu, Gang

    2016-01-01

    Objectives The objective of this study is to mathematically evaluate the influence of multiple factors on implant stability quotient values in clinical practice. Patients and methods Resonance frequency analysis was performed at T1 (measured immediately at the time of implant placement) and at T2 (measured before dental restoration) in 177 patients (329 implants). Using a multivariate linear regression model, we analyzed the influence of the following eleven candidate factors: sex, age, maxillary/mandibular location, bone type, immediate/delayed implantation, bone grafting (presence or absence), insertion torque, I-/II-stage healing pattern, implant diameter, implant length, and T1–T2 time interval. Results The following factors were identified to significantly influence the implant stability quotient (ISQ) values at T1: insertion torque, bone grafting, I-/II-stage healing pattern, immediate/delayed implantation, maxillary/mandibular location, implant diameter, and sex. In contrast, the ISQ values at T2 were significantly influenced only by three factors: implant diameter, T1–T2 time interval, and insertion torque. Conclusion Among the eleven candidate factors, seven key factors were found to influence the T1-ISQ values, while only three key factors influenced the T2-ISQ values. Both T1 and T2-ISQ values were found to be influenced by implant diameter and insertion torque. T1 was influenced specifically by the sex of the patient, the location (maxillary or mandibular), the implantation mode (immediate/delayed implantation), the healing stage, and the absence or presence of bone graft materials. PMID:27785040

  13. Cohort Study to Assess the Impact of Breast Implants on Breastfeeding.

    Science.gov (United States)

    Filiciani, Sandra; Siemienczuk, Guillermo F; Nardín, Juan M; Cappio, Bárbara; Albertengo, Andrés C; Nozzi, Guillermo; Caggioli, Matías

    2016-12-01

    The objective of this study was to evaluate the impact of breast implant surgery and its approaches on lactation by comparing women with and without breast implants at the time of childbirth. Between April of 2013 and July of 2014, in Rosario (Sanatorio de la Mujer and Centro Quirúrgico Rosario), Argentina, a prospective cohort study of women with and without breast implants was performed. Of a total of 3950 births that occurred during this period, 200 patients with similar anthropometric characteristics (maternal and newborn) were selected. Breastfeeding (exclusive or mixed) was compared with artificial feeding at 24 and 48 hours and 30 days in both groups, and the type of incision was also compared. Breastfeeding at 30 days showed a nonsignificant trend favoring the control group (OR, 7.39; 95 percent CI, 0.92 to 339.2). The percentage of women with implants who succeeded in establishing breastfeeding (exclusive or mixed) was very high (93 percent). In the control group, 99 percent of the women were breastfeeding at 30 days. In a comparison of the submammary and areola incision, breastfeeding showed odds ratios of 0.78 (95 percent CI, 0.33 to 1.87) at 24 hours, 1.10 (95 percent CI, 0.48 to 2.56) at 48 hours, and 0.18 (95 percent CI, 0.36 to 1.82) at 30 days. This study shows that most patients with breast implants were able to establish breastfeeding. However, there is a higher number of women without implants that established exclusive breastfeeding. No significant difference was found between the different surgical approaches. Therapeutic, II.

  14. Correction of tuberous breast deformity: A retrospective study comparing lipofilling versus breast implant augmentation.

    Science.gov (United States)

    Brault, Nicolas; Stivala, Alessio; Guillier, David; Moris, Vivien; Revol, Marc; François, Caroline; Cristofari, Sarra

    2017-03-01

    Breast implants and, more recently, autologous fat grafting are the two most common treatments used to correct tuberous breast deformity (TBD). The post-surgical quality of life between the two techniques is not well demonstrated. This study aimed to compare satisfaction and health-related quality of life in patients affected by TBD between these two techniques. All TBD patients operated between January 2008 and May 2015 were retrospectively identified, and only those treated with implants or lipofilling were included. Satisfaction was evaluated at least 6 months after surgery with the postoperative Breast-Q(®) augmentation module. From January 2008 to May 2015, 62 patients were recruited in our study, and 37 patients were evaluated using a Breast-Q questionnaire after at least 6 months of follow-up. Breast implant-augmented patients were significantly more satisfied concerning the "satisfaction with breasts" module (p = 0.002) and the "satisfaction with outcome" module (p = 0.00008). A question-by-question analysis revealed several interesting and significant differences, showing higher scores in most of the questions in the breast implant group. Patients in the lipofilling group, interestingly, had a mean of 1.6 interventions compared to the mean 1.36 interventions in the implant group (p = 0.23). This reflects the need to perform more surgical sessions in the lipofilling group to achieve a satisfactory result. Our study demonstrated that tuberous breast correction with implants can achieve better satisfaction along with good outcomes than lipofilling usually does.

  15. Quality of reporting of descriptive studies in implant dentistry. Critical aspects in design, outcome assessment and clinical relevance

    NARCIS (Netherlands)

    Meijer, Henny J. A.; Raghoebar, Gerry M.

    Objectives: The aim of this study was to conduct a review on quality of reporting on descriptive studies in implant dentistry using the STROBE Statement and to analyse possible changes in quality of reporting on descriptive studies in implant dentistry over time. Material and Methods: A hand search

  16. Quality of reporting of descriptive studies in implant dentistry. Critical aspects in design, outcome assessment and clinical relevance

    NARCIS (Netherlands)

    Meijer, Henny J. A.; Raghoebar, Gerry M.

    2012-01-01

    Objectives: The aim of this study was to conduct a review on quality of reporting on descriptive studies in implant dentistry using the STROBE Statement and to analyse possible changes in quality of reporting on descriptive studies in implant dentistry over time. Material and Methods: A hand search

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

    Science.gov (United States)

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

    2016-11-01

    Present study investigates the photoabsorption properties of single crystal rutile TiO2 (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 (Ti3+ 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 TiO2 surfaces can be important for photo-catalysis.

  18. Randomised controlled trial of extraarticular gold bead implantation for treatment of knee osteoarthritis: a pilot study

    DEFF Research Database (Denmark)

    Nejrup, Kirsten; Olivarius, Niels de Fine; Jacobsen, Judith L.

    2008-01-01

    The primary objective of this double-blind, randomised, controlled trial was to determine if implanting gold beads at five acupuncture points around the knee joint improves 1-year outcomes for patients with osteoarthritis (OA) of the knee. Participants were 43 adults aged 18-80 years with pain...... and stiffness from non-specific OA of the knee for over a year. The intervention was blinded implantation of gold beads at five acupuncture points around the affected knee through a hypodermic needle, or needle insertion alone. Primary outcome measures were knee pain, stiffness and function assessed...... acupuncture had greater relative improvements in self-assessed outcomes. The treatment was well tolerated. This 1-year pilot study indicates that extraarticular gold bead implantation is a promising treatment modality for patients with OA of the knee. The new treatment should be tested in a larger trial...

  19. One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study

    OpenAIRE

    Siddiqi, A; W. J. Duncan; R. K. De Silva; 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-pi...

  20. Clinical investigation of mucosal thickness stability after soft tissue grafting around implants: A 3-year retrospective study

    OpenAIRE

    Speroni Stefano; Cicciù Marco; Maridati Paolo; Grossi Giovanni; Maiorana Carlo

    2010-01-01

    Purpose: To assess the long-term stability of gingival grafts placed around dental implants at the time of second surgery uncovering and to further investigate the association between mucosal thickness (MTh) by demographic variables and clinical investigation. Materials and Methods: Fourteen patients with submerged dental implants covered by inadequate keratinized mucosa were studied. The subjects underwent a periimplant plastic surgery (PPS) at the second-stage dental implant surgery and fr...

  1. Transcriptomic analysis of the myometrium during peri-implantation period and luteolysis–the study on the pig model

    OpenAIRE

    Franczak, Anita; Wojciechowicz, Bartosz; Kolakowska, Justyna; Zglejc, Kamila; KOTWICA, Genowefa

    2014-01-01

    In pigs, implantation begins with the attachment of embryos to the endometrium. As the process is regulated by the expression of numerous genes, endometrial transcriptomic profiles have been extensively studied in early gravid pigs. However, the myometrium, a secretory tissue, should not be neglected, as it can also participate in the regulation of implantation in early pregnant pigs. To clarify this issue, the transcriptomic profile of the porcine myometrium during the peri-implantation peri...

  2. Investigation of the influence of design details on short implant biomechanics using colorimetric photoelastic analysis: a pilot study

    OpenAIRE

    Zielak, João César; Archetti, Felipe Belmonte; Scotton,Ricardo; Filietaz,Marcelo; Carmen Lucia Mueller STORRER; Giovanini,Allan Fernando; Tatiana Miranda DELIBERADOR

    2015-01-01

    Introduction : The clinical survival of a dental implant is directly related to its biomechanical behavior. Since short implants present lower bone/implant contact area, their design may be more critical to stress distribution to surrounding tissues. Photoelastic analysis is a biomechanical method that uses either simple qualitative results or complex calculations for the acquisition of quantitative data. In order to simplify data acquisition, we performed a pilot study to demonstrate the inv...

  3. A clinical study on the effectiveness of implant supported dental restoration in patients with chronic periodontal diseases.

    Science.gov (United States)

    Jiang, B Q; Lan, J; Huang, H Y; Liang, J; Ma, X N; Huo, L D; Xu, X

    2013-02-01

    This study evaluated the efficacy of implant supported dental restorations in patients with chronic periodontal diseases at various stages within 2 years of completing treatment. 30 patients with periodontal diseases and 30 patients without periodontal diseases were studied. Total counts of 276 implant bodies were divided into group A (patients with periodontal diseases; a total of 149 implants) and group B (patients with healthy periodontium; a total of 127 implants). In group A subjects, periodontitis was treated prior to implant placement. The study focused on patients' modified sulcus bleeding index, modified plaque index, implant mobility index, periodontal probing depth and implant success rate 12 and 24 months after the completion of the treatment. The result show: there were no significant differences in implant success rate between groups A and B; modified sulcus bleeding index scores showed differences between the groups 24 months after treatment; there were no significant differences in other clinical indexes during the study between the groups; there were no significant differences in periodontal probing depth between the groups; modified plaque index and modified sulcus bleeding index were positively correlated in implant supported dental restoration patients with chronic periodontal diseases.

  4. [Implantation of collagen coated hydroxyapatite particles. A clinical-histological study in humans].

    Science.gov (United States)

    Sanz, M; Bascones, A; Kessler, A; García Nuñez, J; Newman, M G; Robertson, M A; Carranza, F A

    1989-05-01

    In this study, histologic behaviour of collagen coated hydroxylapatite particles implanted in human periodontal osseous defects has been analyzed. This material was surgically implanted in four patients, and reentry and block biopsies were carried out 4 and 6 months later. The histologic results demonstrate that this material is well tolerated by surrounding tissues, not eliciting an inflammatory reaction. At four months, the hydroxylapatite particles appear encapsulated by a very cellular connective tissue and at 6 months are found in direct contact with osteoid and mature bone. This material acts as a filler material, being fully biocompatible and stimulating an osseoconductive reaction of the adjacent alveolar bone.

  5. Impact of Bruxism on Ceramic Defects in Implant-Borne Fixed Dental Prostheses: A Retrospective Study.

    Science.gov (United States)

    Mikeli, Aikaterini; Walter, Michael H

    2016-01-01

    Ceramic veneer fracture is a frequent complication in implant-borne fixed restorations. The retrospective clinical study assesses the effect of bruxism on this complication. A sample of 507 implant-borne fixed units inserted between 1995 and 2011 in 144 patients were examined. Any detected veneer fractures were assigned to one of four groups according to extent and position. A hypothetical correlation between bruxism and ceramic veneer fractures was examined. Of 34 patients (23.6%) with at least one ceramic veneer fracture, 24 were bruxers (70%) and 10 were nonbruxers (30%) (P = .002). Bruxism may pose a risk for ceramic fractures.

  6. Collagen implant with gentamicin sulphate reduces surgical site infection in vascular surgery: a prospective cohort study.

    Science.gov (United States)

    Costa Almeida, Carlos Eduardo Perdigão; Reis, Luis; Carvalho, Luis; Costa Almeida, Carlos Manuel

    2014-10-01

    Surgical site infection (SSI) is a common complication after vascular surgery. It may cause exposure of the underlying prosthesis causing graft infection, which may require the removal of the vascular graft, increasing amputation and mortality risks. Graft contamination usually occurs during operative procedure or by direct spread from an infected wound. It is therefore advisable to a strong effort in reducing SSI. Topic antibiotics have not been fully studied in vascular surgery, but collagen implant with gentamicin sulphate has shown to reduce SSI in cardiac surgery, orthopaedics, and general surgery procedures. Sixty (60) non-diabetic and non-obese patients with lower limb ischaemia with indication for femoropopliteal PTFE prosthetic bypass were allocated into 2 groups of 30 patients. A collagen implant impregnated with gentamicin sulphate (Collatamp(®)) was applied in the groin incision adjacent to the prosthesis in one group, and the other was a control group. The same surgical team operated all patients. Szilagyi classification was used. There was no SSI (0% - 0/30) in the collagen implant with gentamicin sulphate group, contrasting with 6 cases (20% - 6/30) of SSI (grade I and II) in the control group (p = 0.024). In-hospital day's data shows a significant difference between the two groups (p = 0.004) with a mean of 5.66 days for implant group and 8.10 days for control group. There was no SSI grade III. Collagen implant with gentamicin sulphate (Collatamp(®)) reduces SSI in the groin incision in ischaemic patients submitted to femoropopliteal PTFE prosthetic bypass. Days of hospitalization are also reduced. Decreasing SSI rate and in-hospital days, this implant may also reduce health care costs. Because this is a small pilot study, a multicentre RCT is necessary for validation. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Long-term contraception in a small implant: A review of Suprelorin (deslorelin) studies in cats.

    Science.gov (United States)

    Fontaine, Christelle

    2015-09-01

    Deslorelin (Suprelorin®; Virbac) is a gonadotropin-releasing hormone (GnRH) agonist licensed in select countries for the long-term suppression of fertility in adult male dogs and male ferrets. This article summarizes studies investigating the use of deslorelin implants for the long-term suppression of fertility in male and female domestic cats. Slow-release deslorelin implants have been shown to generate effective, safe and reversible long-term contraception in male and female cats. In pubertal cats, a 4.7 mg deslorelin implant suppressed steroid sex hormones for an average of approximately 20 months (range 15-25 months) in males and an average of approximately 24 months (range 16-37 months) in females. Reversibility has been demonstrated by fertile matings approximately 2 years post-treatment in both male and female adult cats. In prepubertal female cats of approximately 4 months of age, puberty was postponed to an average of approximately 10 months of age (range 6-15 months) by a 4.7 mg deslorelin implant. The large variability in the duration of suppression of gonadal activity makes the definition of the optimal time for reimplantation quite challenging. In addition, the temporary stimulation phase occurring in the weeks following deslorelin implantation can induce in adult female cats a fertile estrus that needs to be managed to avoid unwanted pregnancy. Longer duration and larger scale controlled field studies implementing blinding, a negative control group and a carefully controlled randomization to each group are needed. Furthermore, the effects of repeated treatment need to be investigated. Finally, the effect of treatment on growth and bone quality of prepubertal cats needs to be assessed. However, the ease of use, long-lasting effects and reversibility of deslorelin implants are strong positive points supporting their use for controlling feline reproduction. © The Author(s) 2015.

  8. 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.

  9. Guided tissue regeneration ensures osseointegration of dental implants placed into extraction sockets. An experimental study in monkeys

    DEFF Research Database (Denmark)

    Warrer, L; Gotfredsen, K; Hjørting-Hansen, E

    1991-01-01

    The aim of the present study was to explore the possibility of achieving osseointegration of dental titanium implants, inserted into alveoli immediately after tooth extraction, by covering the recipient site with a teflon membrane. In each of 7 monkeys, mucoperiosteal flaps were raised...... on the buccal and palatal aspects of the maxillary molars in both sides of the jaw. The second molars were then extracted and self tapping titanium implants of the screw type (Astra Dental Implants) were inserted into the sockets of the largest roots. In the coronal portion of the sockets, a void was always...... present between the implant and the socket walls. In one side of the jaw, a membrane (Gore-Tex Augmentation Material) was adjusted to cover the implant. The implant in the other side of the jaw served as control and was only covered by the tissue flaps. Microscopic analysis after 3 months of healing...

  10. Implant-supported overdentures, a prevention of bone loss in edentulous mandibles? A 5-year follow-up study

    DEFF Research Database (Denmark)

    von Wowern, N; Gotfredsen, K

    2001-01-01

    the implants and 3) whether the presence of mandibular osteoporosis affects the loss of bone height around the implants. The material consisted of 22 long-term edentulous healthy persons, 18 women and 4 men from 54 to 78 years of age with 1 Astra Tech Dental Implant in both canine regions, connected by a bar......The purpose of this study were to analyse 1) the changes in the bone mineral content (BMC) in mandibles with implant-supported overdentures when compared with the physiologic age-related mandibular BMC loss, 2) whether the BMC changes were different in groups without or with a bar connecting...... of bone height around implants was measured on periodically identical intraoral radiographs. The fixed parts of the implant-system were stable during the trial in all patients. In conclusion: 1) the increased function after this treatment seems to cause a load-related bone formation which minimizes...

  11. Randomised study for the 1-year crestal bone maintenance around modified diameter implants with different loading protocols: a radiographic evaluation.

    Science.gov (United States)

    Danza, Matteo; Tortora, Pietro; Quaranta, Alessandro; Perrotti, Vittoria; Vozza, Iole; Piattelli, Adriano

    2010-08-01

    This study evaluated by standardised digitised periapical radiography the crestal bone maintenance around modified diameter internal hex implants with variable thread design and narrow neck loaded with different procedures. Forty implants were placed in 25 patients. Twenty implants were conventionally loaded, 20 ones immediately loaded. Radiographs were taken with a customised bite record and processed with software. Measurements of bone from the fixture-abutment junction to mesial and distal marginal bone levels were made. Student's t test statistical analysis was adopted. Baseline data were variable; at 1-year follow-up, there were no significant differences for marginal bone loss between immediately and conventionally loaded maxillary implants (p = 0.1031), whilst there were slight significant differences between immediately and conventionally loaded implants in the mandible (p = 0.0141). Crestal bone maintenance around conventionally and immediately loaded modified diameter implants was similar, with slight significant differences in mandible where a lower marginal bone loss was observed.

  12. Facts and Narrative - the Concept of 4d Capturing of Heritage Building; a Case Study of Sompur Mahavihara, Bangladesh

    Science.gov (United States)

    Rashid, Md. M.; Rahaman, H.

    2013-07-01

    This study embarked upon a premise that considers architecture of building as a dynamic phenomenon. A building from its conception is susceptible to change due to various reasons. An historical building that is several hundred years old must have undergone through changes due to political, social, religious and most importantly functional reasons. Hence capturing building and its dynamic evolution is necessary to appreciate its architecture as well as its heritage value. Whereas the conventional method of fact based historiography only captures the building in particular moment. It makes architectural historians to become perplexed over to which particular moment to be documented. It is a great challenge for the architectural historians to bring back these dynamic characters of the building that are mostly inconspicuous in nature from this point of time. In this situation the historical discourse also remains elusive and blurred. The idea of 4d capturing comes in front in this scenario. Current research would venture into this emerging idea to record the architecture of the early period. This paper highlights the need for a flexible tool to capture this dynamic character of the building. By citing the case study of the 7th century Buddhist Monastery in Bengal, this paper thus argues for the need of capturing the narrative of a historical building than the facts to get a complete picture of its architecture. This study aims at capturing the narrative of Sompur Mahavihara, the UNESCO World Heritage site in Bangladesh, which is currently in ruinous condition. However, it's few hundred years life suggests that as architecture it was subject to change due to different reasons, mainly political, religious and rituals. Being a monument that belongs to the flourishing phase of a society, traditionally this monastery architecture certainly played a role as a stage for religious and political pageantry as well as different religious performances. As architecture it works as

  13. Mechanical, histological and histomorphometric evaluation of modified by femtosecond laser zirconia implants versus titanium implants. An experimental study in dogs at three months

    Directory of Open Access Journals (Sweden)

    J.L. Calvo-Guirado

    2013-06-01

    Full Text Available Aim The present study was aimed at quantifying implant´s stability and elemental composition by Periotest® and evaluating bone to implant contact (BIC and crestal bone loss of modified by femtosecond laser zirconia and titanium implants.Materials and methods Forty-eight implants were divided into 2 groups: titanium (control and modified by femtosecond laser zirconia (test and then inserted in 6 American Foxhound dogs. Primary stability and secondary stability were measured by Periotest, BIC was evaluated by histomorphometry at 1 and 3 months, elemental composition of the surrounding bone in both groups after 1 and 3 months was assessed.Results Differences between groups regarding primary stability and secondary stability were not significant (p>0.05. The Carbon ratio at zirconia (12.529% was significantly lower (p0.05 regarding BIC for titanium vs modified zirconia were observed. Crestal bone loss at 3 months was significantly (p<0.05 lower (0.07 ±0.34 mm in titanium group than in zirconia (1.25 ± 1.73 mm.Conclusion Surface treatment by using femtosecond laser equalizes osseointegration of zirconia implants.

  14. A Case Study Assessing the Auditory and Speech Development of Four Children Implanted with Cochlear Implants by the Chronological Age of 12 Months

    Directory of Open Access Journals (Sweden)

    Birgit May-Mederake

    2013-01-01

    Full Text Available Children with severe hearing loss most likely receive the greatest benefit from a cochlear implant (CI when implanted at less than 2 years of age. Children with a hearing loss may also benefit greater from binaural sensory stimulation. Four children who received their first CI under 12 months of age were included in this study. Effects on auditory development were determined using the German LittlEARS Auditory Questionnaire, closed- and open-set monosyllabic word tests, aided free-field, the Mainzer and Göttinger speech discrimination tests, Monosyllabic-Trochee-Polysyllabic (MTP, and Listening Progress Profile (LiP. Speech production and grammar development were evaluated using a German language speech development test (SETK, reception of grammar test (TROG-D and active vocabulary test (AWST-R. The data showed that children implanted under 12 months of age reached open-set monosyllabic word discrimination at an age of 24 months. LiP results improved over time, and children recognized 100% of words in the MTP test after 12 months. All children performed as well as or better than their hearing peers in speech production and grammar development. SETK showed that the speech development of these children was in general age appropriate. The data suggests that early hearing loss intervention benefits speech and language development and supports the trend towards early cochlear implantation. Furthermore, the data emphasizes the potential benefits associated with bilateral implantation.

  15. Prospective 10-year cohort study based on a randomized controlled trial (RCT) on implant-supported full-arch maxillary prostheses. Part 1: sandblasted and acid-etched implants and mucosal tissue.

    Science.gov (United States)

    Fischer, Kerstin; Stenberg, Torsten

    2012-12-01

    There have been very few long-term controlled studies (i.e., over 5 years duration) focusing on marginal conditions for implants with a sandblasted, large grit, and acid-etched (SLA) surface. To evaluate and report 10-year data on outcomes of implants with an SLA surface placed in the edentulous maxilla. In a randomized controlled trial (RCT) cohort of 24 patients, the outcomes of implants with an SLA surface were registered. The RCT cohort has previously been reported after 1 year, 3 years, and 5 years of loading. One patient dropped out of the study prior to the 10-year control. Of the 23 remaining patients, the implant survival rate was 95.1%. If implants of unknown status were also considered lost, that is, one drop-out patient with three implants for whom no information could be obtained, the implant survival rate was 93%. The mean marginal bone loss from baseline (139 implants) to 10 years (102 implants) was 1.07 mm (standard deviation 0.98). One implant out of 102 available for radiographic examination according to the original protocol showed a bone loss exceeding 4 mm. Of the 84 implants available for clinical examination, none showed a Plaque Index or sulcus bleeding index of 3. The mean implant stability quotient was significantly higher for mesial-distal versus buccal-palatal measurements. The implant survival was 95.1%. The mean value of bone loss after 10 years was 1.07 mm. Peri-implantitis were noted at the 5-year follow-up for one patient with a previous history of periodontitis; this patient did not attend the 10-year follow-up. This study shows that sandblasted and acid-etched implants offers predictable long-term results as support for full-arch maxillary prostheses. © 2011 Wiley Periodicals, Inc.

  16. Estudio piloto comparativo entre cubetas individuales en implantoprótesis Comparative pilot study between custom trays in implant prosthetic

    Directory of Open Access Journals (Sweden)

    A Orozco Varo

    2006-08-01

    Full Text Available El presente trabajo tiene por objeto realizar un estudio piloto sobre las características más idóneas de las cubetas de impresión para prótesis sobre implantes, adjuntando una revisión de la literatura y proponiendo un material y diseño específico para cubetas individuales en prótesis sobre implantes.The present work have to object to make a pilot study about the ideal characteristcs of impression trays for implant prosthodontic, attaching a literature review and suggesting a specific material and desing for custom trays in implant prosthodontic.

  17. Mathematical evaluation of the influence of multiple factors on implant stability quotient values in clinical practice: a retrospective study

    Directory of Open Access Journals (Sweden)

    Huang H

    2016-10-01

    Full Text Available Hairong Huang,1 Daniel Wismeijer,1 Xianhong Shao,2 Gang Wu1 1Department of Oral Implantology and Prosthetic Dentistry, Academic Centre for Dentistry Amsterdam (ACTA, MOVE Research Institute, VU University Amsterdam and University of Amsterdam, Amsterdam, Nord-Holland, the Netherlands; 2Best & Easy Dental Clinic, Hangzhou, Zhejiang Province, People’s Republic of China Objectives: The objective of this study is to mathematically evaluate the influence of multiple factors on implant stability quotient values in clinical practice.Patients and methods: Resonance frequency analysis was performed at T1 (measured immediately at the time of implant placement and at T2 (measured before dental restoration in 177 patients (329 implants. Using a multivariate linear regression model, we analyzed the influence of the following eleven candidate factors: sex, age, maxillary/mandibular location, bone type, immediate/delayed implantation, bone grafting (presence or absence, insertion torque, I-/II-stage healing pattern, implant diameter, implant length, and T1–T2 time interval.Results: The following factors were identified to significantly influence the implant stability quotient (ISQ values at T1: insertion torque, bone grafting, I-/II-stage healing pattern, immediate/delayed implantation, maxillary/mandibular location, implant diameter, and sex. In contrast, the ISQ values at T2 were significantly influenced only by three factors: implant diameter, T1–T2 time interval, and insertion torque.Conclusion: Among the eleven candidate factors, seven key factors were found to influence the T1-ISQ values, while only three key factors influenced the T2-ISQ values. Both T1 and T2-ISQ values were found to be influenced by implant diameter and insertion torque. T1 was influenced specifically by the sex of the patient, the location (maxillary or mandibular, the implantation mode (immediate/delayed implantation, the healing stage, and the absence or presence of bone

  18. Ridge alterations following implant placement in fresh extraction sockets: an experimental study in the dog.

    Science.gov (United States)

    Araújo, Mauricio G; Sukekava, Flavia; Wennström, Jan L; Lindhe, Jan

    2005-06-01

    To study dimensional alterations of the alveolar ridge that occurred following implant placement in fresh extraction sockets. Five beagle dogs were included in the study. In both quadrants of the mandible, incisions were made in the crevice region of the third and fourth pre-molars. Buccal and minute lingual full-thickness flaps were elevated. The mesial root of the four pre-molars root was filled and the teeth were hemi-sected. Following flap elevation in (3)P(3) and (4)P(4) regions, the distal roots were removed. In the right jaw quadrants, implants with a sand blasted and acid etched (SLA) surface were placed in the fresh extraction sockets, while in the left jaws the corresponding sockets were left for spontaneous healing. The mesial roots were retained as surgical control teeth. After 3 months, the animals were examined clinically, sacrificed and tissue blocks containing the implant sites, the adjacent tooth sites (mesial root) and the edentulous socket sites were dissected, prepared for ground sectioning and examined in the microscope. At implant sites, the level of bone-to-implant contact (BC) was located 2.6+/-0.4 mm (buccal aspect) and 0.2+/-0.5 mm (lingual aspect) apical of the SLA level. At the edentulous sites, the mean vertical distance (V) between the marginal termination of the buccal and lingual bone walls was 2.2+/-0.9 mm. At the surgically treated tooth sites, the mean amount of attachment loss was 0.5+/-0.5 mm (buccal) and 0.2+/-0.3 mm (lingual). Marked dimensional alterations had occurred in the edentulous ridge after 3 months of healing following the extraction of the distal root of mandibular pre-molars. The placement of an implant in the fresh extraction site obviously failed to prevent the re-modelling that occurred in the walls of the socket. The resulting height of the buccal and lingual walls at 3 months was similar at implants and edentulous sites and vertical bone loss was more pronounced at the buccal than at the lingual aspect of the

  19. 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

  20. Clinical and radiographic evaluation of single tantalum dental implants: a prospective pilot clinical study

    Science.gov (United States)

    DE FRANCESCO, M.; GOBBATO, E.A.; NOCE, D.; CAVALLARI, F.; FIORETTI, A.

    2016-01-01

    SUMMARY Objective The aim of this prospective pilot clinical case series report was to evaluate, through a clinical and radiographic analysis, the peri-implant bone resorption of the tantalum dental implants (TMT) (Zimmer TMT, Parsippany, NJ, USA) one year after prosthetic rehabilitation. Methods Twenty tantalum dental implants were placed in both maxillas and mandibles of 20 patients. Patients were asked to attend a radiographic and clinical follow-up and their previous clinical records and X-rays were assessed. Bone levels were calculated by digitally measuring the distance from the implant shoulder to the first bone-to-implant on periapical radiographs taken at surgery and after 6 and 12 months of functioning. The Pearson correlation analysis was performed to assess it there was a correlation between the measurement of the marginal bone loss (MBL). The Anova Test with a post-hoc analysis using Bonferroni’s test was used to compare the three group (0, 6 months and 12 months). Results The mean total MBL for the group 0 months was 0.84 mm (SD 0.21), 6 months was 0.87 mm (SD 0.22) and for 12 months was 0.89 mm (SD 0.23). The values of the Pearson’s coefficients showed that the data measurement were positively correlated. The Anova test showed a statistically significant difference between the groups. Conclusion The statistically significant difference in marginal bone loss can be considered physiological. Within the limits of this study it can be concluded that TMT implants have an excellent bone crest’s stability, however, to have most accurate information, will be necessary extend the sample. PMID:28280531

  1. 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.

    2016-01-01

    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 edentul

  2. Bone tissue engineering for spine fusion : An experimental study on ectopic and orthotopic implants in rats

    NARCIS (Netherlands)

    van Gaalen, SM; Dhert, WJA; van den Muysenberg, A; Oner, FC; van Blitterswijk, C; Verbout, AJ; de Bruijn, J.D.

    2004-01-01

    Alternatives to the use of autologous bone as a bone graft in spine surgery are needed. The purpose of this study was to examine tissue-engineered bone constructs in comparison with control scaffolds without cells in a posterior spinal implantation model in rats. Syngeneic bone marrow cells were cul

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

    NARCIS (Netherlands)

    Rashid, F.; Awad, M.A.; Thomason, J.M.; Piovano, A.; Spielberg, G.P.; Scilingo, E.; Mojon, P.; Müller, F.; Spielberg, M.; Heydecke, G.; Stoker, G.; Wismeijer, D.; Allen, F.; Feine, J.S.

    2011-01-01

    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

  4. A Longitudinal Study of Pragmatic Language Development in Three Children with Cochlear Implants

    Science.gov (United States)

    Dammeyer, Jesper

    2012-01-01

    Research has shown how cochlear implants (CIs), in children with hearing impairments, have improved speech perception and production, but very little is known about the children's pragmatic language development. During a 4-year longitudinal study of three children with CIs, certain aspects of pragmatic language development were observed in free…

  5. EXPERIMENTAL STUDY ON ENHANCED HEAT TRANSFER WITH NI-BASED IMPLANTED SPIRAL FINNED TUBES

    Institute of Scientific and Technical Information of China (English)

    Sun Feng-zhong; Huang Xin-yuan; Wang Nai-hua; Shi Yue-tao; Ping Ya-ming

    2003-01-01

    The new type of heat exchanger elements-Ni-based Implanted Spiral Finned Turbes (NISFT) was studied and tested, which can contribute to increase the efficiency and reliability. The relation of Nu, Eu and Re with different fin pitch, fin height, transverse pitch and longitudinal pitch were gained, which constituted the basic foundation for the engineering application of NISFT.

  6. EXPERIMENTAL STUDY OF OSTEOINTERGRATION OF SYNTHETIC MATERIAL POLYTETRAFLUOROETHYLENE IMPLANTED IN BONE

    Directory of Open Access Journals (Sweden)

    V. N. Trezubov

    2010-01-01

    Full Text Available The authors presented the results of experimental study devoted the examination of features of synthetic polymer polytetrafluoroethylene (ePTFE implanted in the bone. It was determined that ePTFE with 70% porosity has the more marked osteointegration and can be recommended for clinical use.

  7. Microstructure of Fe implanted yttria stabilised zirconia studied by Mössbauer spectroscopy and TEM

    NARCIS (Netherlands)

    Burggraaf, A.J.; Scholten, D.; van Hassel, B.A.

    1988-01-01

    Single crystalline and ceramic solid solutions of (1−0.x)(ZrO2)−(0.x)(YO1.5) with x = 14−17 were implanted with high doses of Fe. Specific profile shapes were realised. The microstructure of the material before and after annealing was studied by conversion electron Mössbauer spectroscopy (CEMS), ion

  8. Bacterial colonization of the peri-implant sulcus in dentate patients : a prospective observational study

    NARCIS (Netherlands)

    Stokman, M A; van Winkelhoff, A J; Vissink, A; Spijkervet, F K L; Raghoebar, G M

    2016-01-01

    OBJECTIVES: The aim of the present study was to compare the composition of the periodontal microflora at baseline (T0) with the submucosal microflora at least 1 year after implant placement (T1) in periodontally healthy patients. MATERIAL AND METHODS: For all 169 consecutive patients that visited ou

  9. Dental implants in persons with severe epilepsy and multiple disabilities: a long-term retrospective study

    NARCIS (Netherlands)

    Cune, M.S.; Strooker, H.; van der Reijden, W.A.; de Putter, C.; Laine, M.L.; Verhoeven, J.W.

    2009-01-01

    Purpose: A retrospective study on the performance of endosseous implants in a population of patients with severe epilepsy and additional motor and/or intellectual impairments was performed. Materials and Methods: All residents of an inpatient center for persons affected by severe, refractory

  10. Microstructure of Fe implanted yttria stabilised zirconia studied by Mössbauer spectroscopy and TEM

    NARCIS (Netherlands)

    Burggraaf, A.J.; Scholten, D.; Hassel, van B.A.

    1988-01-01

    Single crystalline and ceramic solid solutions of (1−0.x)(ZrO2)−(0.x)(YO1.5) with x = 14−17 were implanted with high doses of Fe. Specific profile shapes were realised. The microstructure of the material before and after annealing was studied by conversion electron Mössbauer spectroscopy (CEMS), ion

  11. Parenting a Child with a Cochlear Implant: A Critical Incident Study

    Science.gov (United States)

    Zaidman-Zait, Anat

    2007-01-01

    This study aimed to describe and categorize the attributes that parents of young children with cochlear implants (CIs) consider as facilitating their parental coping experience. I interviewed 15 hearing mothers and 13 hearing fathers (including 12 married couples) whose children had CIs, using the critical incident technique that asked parents to…

  12. Novel metallic implantation technique for osteochondral defects of the medial talar dome. A cadaver study

    NARCIS (Netherlands)

    C.J.A. van Bergen; M. Zengerink; L. Blankevoort; M.N. van Sterkenburg; J. van Oldenrijk; C.N. van Dijk

    2010-01-01

    BACKGROUND AND PURPOSE: A metallic inlay implant (HemiCAP) with 15 offset sizes has been developed for the treatment of localized osteochondral defects of the medial talar dome. The aim of this study was to test the following hypotheses: (1) a matching offset size is available for each talus, (2) th

  13. Radiologic evaluation of bone loss at implants with biocide coated titanium abutments: a study in the dog.

    Directory of Open Access Journals (Sweden)

    Roberto López-Píriz

    Full Text Available The objective of the present study is to evaluate bone loss at implant abutments coated with a soda-lime glass containing silver nanoparticles subjected to experimental peri-implantitis. Five beagle dogs were used in the experiments, 3 implants were installed in each quadrant of the mandibles. Glass/n-Ag coted abutments were connected to implant platform. Cotton floss ligatures were placed in a submarginal position around the abutment necks and the animals were subject to a diet which allowed plaque accumulation, and after 15 weeks the dogs were sacrificed. Radiographs of all implant sites were obtained at the beginning and at the end of the experimentally induced peri-implantitis. The radiographic examination indicated that significant amounts of additional bone loss occurred in implants without biocide coating, considering both absolute and relative values of bone loss. Percentages of additional bone loss observed in implants dressed with a biocide coated abutment were about 3 times lower (p<0.006 distal aspect; and p<0.031 at mesial aspect than the control ones. Within the limits of the present study it seems promising the use of soda-lime glass/nAg coatings on abutments to prevent peri-implant diseases.

  14. Finite element study on the effect of abutment length and material on implant bone interface against dynamic loading.

    Science.gov (United States)

    Mishra, Manish; Ozawa, Shogo; Masuda, Tatsuhiko; Yoshioka, Fumi; Tanaka, Yoshinobu

    2011-09-01

    Finite element study on the effect of abutment length and material on implant bone interface against dynamic loading. Two dimensional finite element models of cylinderical implant, abutments and bone made by titanium or polyoxymethylene were simulated with the aid of Marc/Mentat software. Each model represented bone, implant and titanium or polyoxymethylene abutment. Model 1: Implant with 3 mm titanium abutment, Model 2: Implant with 2 mm polyoxymethylene resilient material abutment, Model 3: Implant with 3 mm polyoxymethylene resilient material abutment and Model 4: Implant with 4 mm polyoxymethylene resilient material abutment. A vertical load of 11 N was applied with a frequency of 2 cycles/sec. The stress distribution pattern and displacement at the junction of cortical bone and implant was recorded. When Model 2, 3 and 4 are compared with Model 1, they showed narrowing of stress distribution pattern in the cortical bone as the height of the polyoxymethylene resilient material abutment increases. Model 2, 3 and 4 showed slightly less but similar displacement when compared to Model 1. Within the limitation of this study, we conclude that introduction of different height resilient material abutment with different heights i.e. 2 mm, 3 mm and 4 mm polyoxymethylene, does not bring about significant change in stress distribution pattern and displacement as compared to 3 mm Ti abutment. Clinically, with the application of resilient material abutment there is no significant change in stress distribution around implant-bone interface.

  15. Radiologic evaluation of bone loss at implants with biocide coated titanium abutments: a study in the dog.

    Science.gov (United States)

    López-Píriz, Roberto; Solá-Linares, Eva; Granizo, Juan J; Díaz-Güemes, Idohia; Enciso, Silvia; Bartolomé, José F; Cabal, Belén; Esteban-Tejeda, Leticia; Torrecillas, Ramón; Moya, José S

    2012-01-01

    The objective of the present study is to evaluate bone loss at implant abutments coated with a soda-lime glass containing silver nanoparticles subjected to experimental peri-implantitis. Five beagle dogs were used in the experiments, 3 implants were installed in each quadrant of the mandibles. Glass/n-Ag coted abutments were connected to implant platform. Cotton floss ligatures were placed in a submarginal position around the abutment necks and the animals were subject to a diet which allowed plaque accumulation, and after 15 weeks the dogs were sacrificed. Radiographs of all implant sites were obtained at the beginning and at the end of the experimentally induced peri-implantitis. The radiographic examination indicated that significant amounts of additional bone loss occurred in implants without biocide coating, considering both absolute and relative values of bone loss. Percentages of additional bone loss observed in implants dressed with a biocide coated abutment were about 3 times lower (p<0.006 distal aspect; and p<0.031 at mesial aspect) than the control ones. Within the limits of the present study it seems promising the use of soda-lime glass/nAg coatings on abutments to prevent peri-implant diseases.

  16. [Implant-borne prosthetic rehabilitation in patients with cleft lip and palate: A retrospective study on 43 patients].

    Science.gov (United States)

    Borgnat, F; Martin, P; Paulus, C

    2015-09-01

    Implant-borne rehabilitation in cleft lip and palate patient are aimed to allow for good orofacial functions, stable occlusion, and adequate support for the naso-labial region. The goal of our study was to evaluate the functional and esthetic results of the implant-born dental rehabilitation of the cleft lip and palate patients in our department. Our retrospective study concerned patients operated between 1995 and 2010 in our department. All included patients suffered from a cleft alveolus and lip, with or without cleft palate. Dental implants were placed in the bone-grafted alveolus and the end of growth and at distance from the bone graft procedure. Criteria of implant survival and implant-borne rehabilitation success were defined. A total of 78 implants were placed in 43 patients between 1995 and 2010. Two implants were lost (implant survival rate: 97.4%). Despite this loss, all the patients could be rehabilitated with good functional and esthetic results. Implant-borne rehabilitation is a reliable solution for prosthetic rehabilitation in patients with cleft lip and palate. This solution allows for avoiding removable prosthesis and dental mutilation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. A Comparative Study of the Application of FACTS Devices in Wind Power Plants of the Southeast Area of the Mexican Electric System

    Energy Technology Data Exchange (ETDEWEB)

    Beltran-Valle, Omar; Pena-Gallardo, Rafael; Segundo-Ramirez, Juan; Muljadi, Eduard

    2017-01-26

    This paper presents a comparative study of the application of Flexible AC Transmission System (FACTS) devices, as Thyristor Controlled Series Capacitor (TCSC), Static Synchronous Compensator (STATCOM) and Unified Power Controller (UPFC) on congestion management and voltage support in the area of the Istmo of Tehuantepec, Oaxaca, Mexico. The present work provides an analysis about the performance of the control of active and reactive power of the FACTS controllers applied to mentioned problems in the power system.

  18. Biomechanical and histologic basis of osseodensification drilling for endosteal implant placement in low density bone. An experimental study in sheep.

    Science.gov (United States)

    Lahens, Bradley; Neiva, Rodrigo; Tovar, Nick; Alifarag, Adham M; Jimbo, Ryo; Bonfante, Estevam A; Bowers, Michelle M; Cuppini, Marla; Freitas, Helora; Witek, Lukasz; Coelho, Paulo G

    2016-10-01

    A bone drilling concept, namely osseodensification, has been introduced for the placement of endosteal implants to increase primary stability through densification of the osteotomy walls. This study investigated the effect of osseodensification on the initial stability and early osseointegration of conical and parallel walled endosteal implants in low density bone. Five male sheep were used. Three implants were inserted in the ilium, bilaterally, totaling 30 implants (n=15 conical, and n=15 parallel). Each animal received 3 implants of each type, inserted into bone sites prepared as follows: (i) regular-drilling (R: 2mm pilot, 3.2mm, and 3.8mm twist drills), (ii) clockwise osseodensification (CW), and (iii) counterclockwise (CCW) osseodensification drilling with Densah Bur (Versah, Jackson, MI, USA): 2.0mm pilot, 2.8mm, and 3.8mm multi-fluted burs. Insertion torque as a function of implant type and drilling technique, revealed higher values for osseodensification relative to R-drilling, regardless of implant macrogeometry. A significantly higher bone-to-implant contact (BIC) for both osseodensification techniques (pdrilling. There was no statistical difference in BIC as a function of implant type (p=0.58), nor in bone-area-fraction occupancy (BAFO) as a function of drilling technique (p=0.22), but there were higher levels of BAFO for parallel than conic implants (p=0.001). Six weeks after surgery, new bone formation along with remodeling sites was observed for all groups. Bone chips in proximity with the implants were seldom observed in the R-drilling group, but commonly observed in the CW, and more frequently under the CCW osseodensification technique. In low-density bone, endosteal implants present higher insertion torque levels when placed in osseodensification drilling sites, with no osseointegration impairment compared to standard subtractive drilling methods.

  19. 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.

  20. Effect of Ultraviolet Irradiation of the Implant Surface on Progression of Periimplantitis--A Pilot Study in Dogs.

    Science.gov (United States)

    Ishii, Kouken; Matsuo, Masato; Hoshi, Noriyuki; Takahashi, Shun-Suke; Kawamata, Ryota; Kimoto, Katsuhiko

    2016-02-01

    The objective of this study was to investigate morphologically the progression of periimplantitis around an ultraviolet (UV)-light-irradiated implant in dogs. Pure titanium implants (3.3 mm in diameter and 8 mm long) were placed into dog jawbone bilaterally. Implants on one side were irradiated with UV light for 15 minutes using a photodevice immediately before placement (UV group), whereas those on the other side were not irradiated (non-UV group). Osseointegration was confirmed 90 days after implant placement by radiography. Experimental periimplantitis was induced by the application of dental floss over 90 days. Clinical and radiographic examination and micro-computed tomography (micro-CT) were performed after 90 and 180 days, and bone resorption was measured. The bone-implant interface in tissue sections was examined by light microscopy. Bone resorption around the UV-irradiated implant was less pronounced than around the non-UV-irradiated implant in the ligature-induced periimplantitis model. Tissue section images revealed no contact and partial destruction at the bone-implant interface. Within the limitations of this preliminary investigation, it is suggested that UV-light-irradiated implants suppress spontaneous progression of periimplantitis.

  1. Comparison of Lyophilized Glutaraldehyde-Preserved Bovine Pericardium with Different Vascular Prostheses for Use as Vocal Cords Implants: Experimental Study

    Science.gov (United States)

    Olmos-Zuñiga, J. Raúl; Jasso-Victoria, Rogelio; Gaxiola-Gaxiola, Miguel; Sotres-Vega, Avelina; Hernández-Jiménez, Claudia; Baltazares-Lipp, Matilde; Arredondo del Bosque, Fernando; Santillan-Doherty, Patricio

    2015-01-01

    This study compared the use of lyophilized glutaraldehyde-preserved bovine pericardium (LGPBP), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), and Teflon felt (TF) as implants for vocal cords (VC) medialization and aimed to assess the endoscopic, macroscopic, and microscopic VC changes after medialization in a canine model. In 18 mongrel dogs, the right VC were medialized with LGPBP and the left were implanted as follows: Group I (n = 6): LGPBP and PTFE; Group II (n = 6): LGPBP and PET; Group III (n = 6): LGPBP and TF. Surgical handling of the implants was compared. Three months after surgery, macroscopic and microscopic changes of VC and implants were evaluated. LGPBP offered the best surgical handling (p = 0.005, Kruskal-Wallis). TF implants showed extrusion (p = 0.005, Kruskal-Wallis) and severe inflammation. All VC formed fibrous capsules around the implants; the ones developed by LGPBP implants were thinner (p = 0.001, ANOVA, Tukey). VC implanted with synthetic materials showed eosinophilic infiltration (p = 0.01, Kruskal-Wallis). We concluded that the LGPBP could be used as an implant for VC medialization because it is biocompatible, easy to handle and remove during surgical procedures, and nonabsorbable or extrudable and produces an inflammatory reaction similar to PTFE and PET. PMID:26075232

  2. Fact Finding Nuclear Energy; Fact Finding Kernenergie

    Energy Technology Data Exchange (ETDEWEB)

    Scheepers, M.J.J.; Seebregts, A.J.; Lako, P. [ECN-Beleidsstudies, Petten (Netherlands); Blom, F.J.; Van Gemert, F. [Sociaal-Economische Raad SER, Den Haag (Netherlands)

    2007-09-15

    Facts and figures on nuclear energy are presented to enable a discussion on the role of nuclear power in the transition to a sustainable energy supply for the Netherlands. The following issues are presented: Nuclear technology, safety and security (including non-proliferation and protection against terrorism); Environmental aspects (including greenhouse gas emissions of the nuclear energy lifecycle); Nuclear power and the power market (including impact of nuclear power on electricity market prices); Economic aspects (including costs of nuclear power and external costs and benefits); Policy issues (including sustainable development); Social acceptance of nuclear energy; Knowledge infrastructure for nuclear energy in the Netherlands; and Nuclear power in long term energy scenarios for the Netherlands and Europe. Using two long-term energy scenarios the report also presents a social impact analysis of an increasing share of nuclear power in the Dutch electricity supply. [Dutch] In dit onderzoek zijn feiten en gegevens over kernenergie verzameld op basis van bestaande inzichten en een veelheid aan literatuur (fact finding). Voor technologische expertise heeft ECN zich laten bijstaan door de Nucleair Research and consultancy Group (NRG). Op basis van de fact-finding studie bereidt de SER een advies voor over de rol van kernenergie in de toekomstige nationale elektriciteitsproductie. In de eerste acht hoofdstukken worden feiten en gegevens gepresenteerd over verschillende onderwerpen die bij kernenergie van belang zijn. In Hoofdstuk 2 wordt de kernenergietechnologie beschreven, inclusiefde veiligheid van kernenergie besproken, omdat die nauw met de technologie samenhangt. Hierbij gaat het om de technische veiligheid van de installaties, maar ook om beveiliging tegen misbruik van technologie en nucleair materiaal, waaronder beveiliging tegen terrorisme. De milieuaspecten door radioactiviteit en door emissies van kooldioxide die met het gebruik van kernenergie samenhangen

  3. A real-life observational study of the effectiveness of FACT in a Dutch mental health region

    Directory of Open Access Journals (Sweden)

    Poddighe Giovanni

    2008-12-01

    Full Text Available Abstract Background ACT is an effective community treatment but causes discontinuity of care between acutely ill and currently stable patient groups. The Dutch variant of ACT, FACT, combines both intensive ACT treatment and care for patients requiring less intensive care at one time point yet likely to need ACT in the future. It may be hypothesised that this case mix is not beneficial for patients requiring intensive care, as other patient groups may "dilute" care provision. The effectiveness of FACT was compared with standard care, with a particular focus on possible moderating effects of patient characteristics within the case mix in FACT. Methods In 2002, three FACT teams were implemented in a Dutch region in which a cumulative routine outcome measurement system was in place. Patients receiving FACT were compared with patients receiving standard treatment, matched on "baseline" symptom severity and age, using propensity score matching. Outcome was the probability of being in symptomatic remission of psychotic symptoms. Results The probability of symptomatic remission was higher for SMI patients receiving FACT than for controls receiving standard treatment, but only when there was an unmet need for care with respect to psychotic symptoms (OR = 6.70, p = 0.002; 95% CI = 1.97 – 22.7. Conclusion Compared to standard care, FACT was more rather than less effective, but only when a need for care with respect to psychotic symptoms is present. This suggests that there is no adverse effect of using broader patient mixes in providing continuity of care for all patients with severe mental illness in a defined geographical area.

  4. Thermodynamic effects after Diode and Er:YAG laser irradiation of grade IV and V titanium implants placed in bone - an ex vivo study. Preliminary report.

    Science.gov (United States)

    Matys, Jacek; Botzenhart, Ute; Gedrange, Tomasz; Dominiak, Marzena

    2016-10-01

    Many inserted implants are affected by peri-implantitis. The aim of our study was to evaluate increases in implant temperature, depending on the diameter and chemical composition of implants. In particular we measured the time it takes for the temperature of an implant to rise by 10°C and evaluated laser power settings required to prevent thermal injury when an implant surface is decontaminated during the treatment of peri-implantitis. The study analysed six implants placed in porcine ribs and divided into two groups according to their diameter and chemical composition (grade IV and grade V titanium). The implants were irradiated with Diode and Er:YAG lasers using different laser parameters. The temperature was measured with a K-type thermocouple. The temperature on the implant surface rose as the laser power increased and the implant diameter decreased. The time required to increase the temperature of an implant by 10°C was less than it was for titanium grade IV. The temperature gradient was below 10°C for all implants treated using a laser power up to 1 W. It is important to choose the correct laser parameters, depending on the chemical composition and diameter of the implant, so that decontamination of the implant surface is thorough, effective and safe.

  5. Marijuana (Weed, Pot) Facts

    Science.gov (United States)

    ... That People Abuse » Marijuana (Weed, Pot) Facts Marijuana (Weed, Pot) Facts Listen Marijuana is a green, brown, or gray mix of dried, shredded leaves and flowers from the marijuana plant. Marijuana can be rolled up and smoked ...

  6. Zika Virus Fact Sheet

    Science.gov (United States)

    ... sheets Fact files Questions & answers Features Multimedia Contacts Zika virus Fact sheet Updated 6 September 2016 Key ... and last for 2-7 days. Complications of Zika virus disease Based on a systematic review of ...

  7. Facts about Amblyopia

    Science.gov (United States)

    ... Health Information > Amblyopia > Facts About Amblyopia Facts About Amblyopia This information was developed by the National Eye ... is the best person to answer specific questions. Amblyopia Defined What is amblyopia? The brain and the ...

  8. Cholesterol Facts and Statistics

    Science.gov (United States)

    ... Blood Pressure Salt Million Hearts® WISEWOMAN Program High Cholesterol Facts Recommend on Facebook Tweet Share Compartir As ... the facts about high cholesterol [PDF-281K] . High Cholesterol in the United States 73.5 million adults ( ...

  9. Trauma Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Physical Trauma Fact Sheet Physical Trauma Fact Sheet Tagline (Optional) Middle/Main Content Area ... of physical trauma. Credit: iStock. What is physical trauma? Physical trauma is a serious injury to the ...

  10. Diabetes Fact Sheet

    Science.gov (United States)

    ... diabetes by losing weight. Related information Fitness and nutrition Heart disease and stroke Obesity and weight loss fact sheet Physical activity fact sheet Pregnancy The javascript used in this widget is not ...

  11. Organ Facts: Pancreas

    Science.gov (United States)

    ... Lung Kidney Pancreas Kidney/Pancreas Liver Intestine Pancreas Facts The pancreas is a five to six inch ... Camps for kids Contacting my donor family Data Facts about living donation Financing a transplant Matching organs ...

  12. Facts about Type 2

    Medline Plus

    Full Text Available ... Text Size: A A A Listen En Español Facts About Type 2 Type 2 diabetes is the ... 2, In this section Diabetes Basics Type 2 Facts About Type 2 Recently Diagnosed Treatment and Care ...

  13. Meningitis Myths and Facts

    Science.gov (United States)

    ... Diseases Infographic Prevention and Control of Meningococcal Disease Meningitis Myths and Facts Myth: Meningococcal disease is easy ... infected person, such as shaking hands. Fact: Meningococcal meningitis is spread through air droplets and direct contact ...

  14. Oral rehabilitation with implant-supported fixed partial dentures in periodontitis-susceptible subjects. A 5-year prospective study.

    Science.gov (United States)

    Wennström, Jan L; Ekestubbe, Annika; Gröndahl, Kerstin; Karlsson, Stig; Lindhe, Jan

    2004-09-01

    Comparatively few studies with at least 5 years of follow-up are available that describe the use of implants in prosthetic rehabilitation of partially edentulous patients. Randomized, controlled clinical studies that evaluated the effect of different surface designs of screw-shaped implants on the outcome of treatment are also sparse. To determine, in a prospective randomized, controlled clinical trial, the outcome of restorative therapy in periodontitis-susceptible patients who, following basic periodontal therapy, had been restored with implants with either a machined- or a rough-surface topography. Fifty-one subjects (mean age, 59.5 years), 20 males and 31 females who, following treatment of moderate-to-advanced chronic periodontitis, required implant therapy for prosthetic rehabilitation were recruited. Seventeen of the patients were current smokers. Following the active treatment, all subjects were included in an individually designed maintenance program. A total of 56 fixed partial dentures (FPDs) and a total of 149 screw-shaped, and self-tapping implants (Astra Tech implants) -- 83 in the maxilla and 66 in the mandible -- were installed in a two-stage procedure. Each patient received a minimum of two implants and by randomization every second implant that was installed had been designed with a machined surface and the remaining with a roughened Tioblast surface. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographical examinations were performed following FPD connection and once a year during a 5-year follow-up period. The analysis of peri-implant bone-level alterations was performed on subject, FPD and implant levels. Four patients and four FPDs were lost to the 5 years of monitoring. One implant (machined surface) did not properly integrate (early failure), and was removed at the time of abutment connection. Three implants were lost during function and a further eight implants could not be accounted for at the 5

  15. Accuracy of cited "facts" in medical research articles: A review of study methodology and recalculation of quotation error rate.

    Science.gov (United States)

    Mogull, Scott A

    2017-01-01

    Previous reviews estimated that approximately 20 to 25% of assertions cited from original research articles, or "facts," are inaccurately quoted in the medical literature. These reviews noted that the original studies were dissimilar and only began to compare the methods of the original studies. The aim of this review is to examine the methods of the original studies and provide a more specific rate of incorrectly cited assertions, or quotation errors, in original research articles published in medical journals. Additionally, the estimate of quotation errors calculated here is based on the ratio of quotation errors to quotations examined (a percent) rather than the more prevalent and weighted metric of quotation errors to the references selected. Overall, this resulted in a lower estimate of the quotation error rate in original medical research articles. A total of 15 studies met the criteria for inclusion in the primary quantitative analysis. Quotation errors were divided into two categories: content ("factual") or source (improper indirect citation) errors. Content errors were further subdivided into major and minor errors depending on the degree that the assertion differed from the original source. The rate of quotation errors recalculated here is 14.5% (10.5% to 18.6% at a 95% confidence interval). These content errors are predominantly, 64.8% (56.1% to 73.5% at a 95% confidence interval), major errors or cited assertions in which the referenced source either fails to substantiate, is unrelated to, or contradicts the assertion. Minor errors, which are an oversimplification, overgeneralization, or trivial inaccuracies, are 35.2% (26.5% to 43.9% at a 95% confidence interval). Additionally, improper secondary (or indirect) citations, which are distinguished from calculations of quotation accuracy, occur at a rate of 10.4% (3.4% to 17.5% at a 95% confidence interval).

  16. Penile Implants

    Science.gov (United States)

    ... the discussion with your doctor. Types of penile implants There are two main types of penile implants: ... might help reduce the risk of infection. Comparing implant types When choosing which type of penile implant ...

  17. A Retrospective Cohort Study on the Influence of Comorbidity on Soft Tissue Reactions, Revision Surgery, and Implant Loss in Bone-anchored Hearing Implants.

    Science.gov (United States)

    den Besten, Christine A; Nelissen, Rik C; Peer, Petronella G M; Faber, Hubert T; Dun, Catherina A J; de Wolf, Maarten J F; Kunst, Henricus P M; Cremers, Cor W R J; Mylanus, Emmanuel A M; Hol, Myrthe K S

    2015-06-01

    To identify risk factors for complications after bone-anchored hearing implant (BAHI) surgery. Retrospective cohort study. Tertiary referral center. All adult patients who received titanium bone-anchored hearing implants at our clinic between September 1, 1988 and December 31, 2007 were approached to fill out a questionnaire on comorbidity factors. A total of 581 patients with 669 implants were included in the analysis. Implant loss, soft tissue reactions, and revision surgery after BAHI implantation. Skin disease and profound learning difficulties were risk factors for time to first soft tissue reaction, hazard rate ratio of 3.41 (95% CI 1.45-8.01) and 3.42 (1.03-11.39), respectively. Female gender showed a trend toward a negative risk for time to first soft tissue reaction, hazard rate ratio 0.60 (0.35-1.03). In multivariable analysis, skin disease and female gender were observed as independent associative factors, adjusted hazard ratio 3.08 (1.32-7.16) and 0.56 (0.33-0.94). For revision surgery, female gender and cardiovascular disease were identified as negative risk factors in univariable analysis, and smoking showed a trend toward a negative risk, with hazard ratios of 0.15 (0.07-0.32), 0.07 (0.03-0.20), and 0.51 (0.24-1.07), respectively. In multivariable analysis, smoking and female gender were observed as independent associative factors, adjusted hazard ratio 0.45 (0.22-0.95) and 0.14 (0.06-0.30). Smoking could be identified as a risk factor for implant loss with a hazard ratio of 3.32 (1.36-8.09). Retrospective analysis of comorbidity factors and clinical outcomes revealed risk factors for postoperative complications after BAHI surgery.

  18. Implant placement in the atrophic posterior maxilla with sinus elevation without bone grafting: a 2-year prospective study.

    Science.gov (United States)

    Rajkumar, Garudanahally Chikkalingaiah; Aher, Vinit; Ramaiya, Shashikala; Manjunath, Gavi Siddhaiah; Kumar, Devaraj Veerendra

    2013-01-01

    The purpose of this study was to evaluate changes in alveolar bone height after direct sinus elevation and simultaneous implant placement in the posterior edentulous maxilla. A prospective clinical study was conducted of patients undergoing sinus elevation for implant placement in the posterior maxilla to replace missing teeth. Residual alveolar bone height was between 4 and 7.5 mm. Lateral osteotomy of the maxillary sinus, followed by simultaneous implant placement without bone grafting, was performed under local anesthesia. Prosthetic restoration was completed 9 months later. The changes in alveolar bone height at the sinus floor were assessed radiographically after 1 week and 6, 9, 18, and 28 months after implant placement. Probing depths, implant mobility, and crestal bone loss were assessed at the same intervals. Twenty-eight patients (17 women and 11 men) participated in the study. Forty-five implants were placed and followed after prosthetic rehabilitation. At 18 months after loading of the implants, alveolar bone height in the area of sinus elevation ranged from 7.40 to 11.55 mm. Increases in alveolar bone height at the sinus floor ranged from 2.05 to 5.40 mm at a minimum of 18 months after loading, a statistically significant gain. Crestal bone loss and changes in probing depths were not significant in any patients, and all implants remained clinically stable. The implant success rate was 100% without any complications after 18 to 28 months of follow-up. Placement of endosseous implants in the atrophic posterior maxilla in conjunction with sinus elevation without bone grafting resulted in a significant amount of bone formation around the implants at the sinus floor, resulting in successful restorations and eliminating the need for bone grafting.

  19. Mathematical evaluation of the influence of multiple factors on implant stability quotient values in clinical practice : A retrospective study

    NARCIS (Netherlands)

    Huang, H.; Wismeijer, D.; Shao, X.; Wu, G.

    2016-01-01

    Objectives: The objective of this study is to mathematically evaluate the influence of multiple factors on implant stability quotient values in clinical practice. Patients and methods: Resonance frequency analysis was performed at T1 (measured immediately at the time of implant placement) and at T2

  20. 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)

  1. Nanomechanical properties of bone around cement-retained abutment implants. A minipig study

    Directory of Open Access Journals (Sweden)

    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.

  2. Nitrogen ion implantation on stainless steel: AFM study of surface modification

    Energy Technology Data Exchange (ETDEWEB)

    Chico, B. [Dpto. Ingenieria de Materiales, Degradacion y Durabilidad, Centro Nacional de Investigaciones Metalurgicas (CENIM), CSIC, Avda. Gregorio del Amo, 8, 28040 Madrid (Spain)]. E-mail: bchico@cenim.csic.es; Martinez, L. [Dpto. Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Perez, F.J. [Dpto. Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid (Spain)

    2005-04-30

    This work presents a study by means of atomic force microscopy (AFM) of the modification of the surface topography of AISI 304 austenitic stainless steel after N-ion implantation, irradiated by 1 x 10{sup 15} N{sub 2}{sup +}/cm{sup 2} at 80 keV. Prior to the implantation surface modification, the samples were electropolished for the optimum observation of the surface at a small scale to obtain an initial surface with the smaller roughness. The electrolytic bath was composed of a mixture of water/sulphuric acid/orthophosphoric acid in percentages 20, 20 and 60%, respectively. Once the surface was optimized, the samples were implanted and observed by AFM, a new technique whose importance relies on its resolution power, allowing the acquisition of topographic images of the surface with nanometric resolution. Thanks to the high resolution power could be observed that ion implantation increases the surface roughness and promotes the apparition of 3 {mu}m wide and 10 nm depth craters as well as the apparition of products with singular morphology.

  3. Raman scattering studies on manganese ion-implanted GaN

    Institute of Scientific and Technical Information of China (English)

    Xu Da-Qing; Zhang Yi-Men; Zhang Yu-Ming; Li Pei-Xian; Wang Chao

    2009-01-01

    This paper reports that the Raman spectra have been recorded on the metal-organic chemical vapour deposition epitaxially grown GaN before and after the Mn ions implanted.Several Raman defect modes have emerged from the implanted samples.The structures around 182 cm-1 modes are attributed to the disorder-activated Raman scattering,whereas the 361 cm-1 and 660 cm-1 peaks are assigned to nitrogen vacancy-related defect scattering.One additional peak at 280 cm-1 is attributed to the vibrational mode of gallium vacancy-related defects and/or to disorder activated Raman scattering.A Raman-scattering study of lattice recovery is also presented by rapid thermal annealing at different temperatures between 700℃ and 1050℃ on Mn implanted GaN epilayers.The behaviour of peak-shape change and full width at half maximum(FWHM)of the A1(LO)(733 cm-1)and EH2(566 cm-1)Raman modes are explained on the basis of implantation-induced lattice damage in GaN epilayers.

  4. Exploratory study of perceived quality of life with implanted standing neuroprostheses

    Directory of Open Access Journals (Sweden)

    Loretta M. Rohde, PT, DPT

    2012-04-01

    Full Text Available Individuals with spinal cord injury (SCI need options for negotiating architectural barriers, completing essential transfers, and accessing items on high shelves or in cupboards that cannot be reached from the wheelchair or safely managed with reachers. Case Western Reserve University (CWRU and the Department of Veterans Affairs (VA have developed an assistive technology device to assist individuals with SCI to stand and transfer. The 8-channel implanted CWRU-VA system enables persons with SCI to exercise, stand, and maneuver in the vicinity of their wheelchairs. Interventions that decrease barriers to mobility and participation can have a significant effect on an individual’s perceived quality of life (QOL. This study uses a qualitative research methodology comprised of a series of semi-structured interviews to determine the effects on perceived QOL of an implanted 8-channel functional electrical stimulation (FES system for standing after SCI. The results reveal that individuals with SCI currently using an implanted FES standing system perceived significant improvements in QOL related to the neuroprosthesis. Implanted neuroprostheses for standing have the potential to improve QOL for veterans living with SCI.

  5. Ellipsometric study of crystalline silicon hydrogenated by plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Szekeres, A. [Institute of Solid State Physics, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Alexandrova, S. [Department of Applied Physics, Technical University of Sofia, Kl. Ohridski 8, 1797 Sofia (Bulgaria); Petrik, P., E-mail: petrik@mfa.kfki.hu [MFA Institute for Technical Physics and Materials Science, TTK Research Centre for Natural Sciences, Konkoly Thege Rd. 29-33, 1121 Budapest (Hungary); Fodor, B. [MFA Institute for Technical Physics and Materials Science, TTK Research Centre for Natural Sciences, Konkoly Thege Rd. 29-33, 1121 Budapest (Hungary); Bakalova, S. [Institute of Solid State Physics, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria)

    2013-09-15

    The structure and the optical properties of thin Si layer hydrogenated by shallow plasma ion implantation with different fluences up to 10{sup 15} cm{sup −2} are studied using spectroscopic ellipsometry and simulation of the distributions of the ions and implantation induced defects. The implantation was regarded to proceed into Si through the native SiO{sub 2}. Two-layer optical models are applied for examination of the composition and dielectric function behavior of the formed structures. The native oxide is found to be 3 nm thick. The thickness of the Si modified layer decreased 23 to 14 nm with ion fluence due to increased formation of highly hydrogenated surface region that hinder further H-penetration into the Si bulk, especially at the highest fluence. Shifts of the features in the obtained dielectric functions related with Si interband transitions at about 3.4 and 4.2 eV are found caused by process-induced tensile stress. The modified Si region is related rather to defects created by the ion implantation process than the projected range of hydrogen ions. The overall layer modification can be characterized by a low degree of amorphization (up to 5.8%), creation of structural defects and internal tensile stress.

  6. ERD studies of D-ion depth distributions after implantation into some pure metals and alloys

    Science.gov (United States)

    Didyk, A. Yu.; Wiśniewski, R.; Wilczynska, T.; Kitowski, K.; Hofman, A.

    2012-01-01

    This paper presents a report on experimental results of depth distributions of deuterium ions implanted with 25 keV energy at a fluence interval of (1.2-2.3) × 1022 m-2 into samples of pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh). The post-treatment depth distributions of deuterium and hydrogen atoms were measured within a few hours after implantation with the use of elastic recoil detection (ERD) analysis. After three months the measurements were repeated. The comparison of the obtained results in both series of studies allowed us to make an important observation of the desorption rates of implanted deuterium atoms from pure metals and diluted Pd alloys. The maximum measured concentrations of deuterium atoms in pure Zr and Ti foils with relatively small desorption rate of deuterium atoms within three months after implantation were observed. Also a very high spreading of deuterium atom distributions was observed in all the measured pure metals and alloys. It can be explained by the large diffusion coefficients of deuterium and extremely fast kinetics.

  7. a Study of the Dosimetry of IODINE-125 Seed Interstitial Implants Using Monte Carlo Simulation Methods.

    Science.gov (United States)

    Burns, Gregory Scott

    Monte Carlo simulation methods were used to investigate the absorbed dose distribution around several preliminary source configurations and the 3M Company models 6701, 6702, and 6711 I-125 seeds in water. Simulations for the preliminary sources, all of which were structurally simpler than the seeds, were conducted to demonstrate correct behavior of the computer software. The relative dose distributions of the three seed models were found to be anisotropic, and distinct. Observed differences in the relative dose distributions of the three models are attributable to differences in seed design and photon emission spectrum. Variations in end weld thicknesses and radioactivity distributions within the seeds were found to have substantial influence on the relative dose distributions. Dosimetry estimates along the longitudinal axis of the seeds are particularly uncertain due to such variations. Finally, perturbations of the single seed dose distribution created by neighboring seeds within the implant were determined. Such perturbations are strongly dependent on the seed model used and on the separation between seeds. Simple superposition of single seed dose distributions in multiple seed implants causes overestimation of dose within seed planes. Errors may be quite large for single plane implants with small seed separations. The results of this study provide a means to reduce errors in iodine seed implant dosimetry through the use of seed design-specific two-dimensional dosimetry data, and through improved understanding of the causes of uncertainties in iodine seed relative dose distributions.

  8. Exploratory study of perceived quality of life with implanted standing neuroprostheses.

    Science.gov (United States)

    Rohde, Loretta M; Bonder, Bette R; Triolo, Ronald J

    2012-01-01

    Individuals with spinal cord injury (SCI) need options for negotiating architectural barriers, completing essential transfers, and accessing items on high shelves or in cupboards that cannot be reached from the wheelchair or safely managed with reachers. Case Western Reserve University (CWRU) and the Department of Veterans Affairs (VA) have developed an assistive technology device to assist individuals with SCI to stand and transfer. The 8-channel implanted CWRU-VA system enables persons with SCI to exercise, stand, and maneuver in the vicinity of their wheelchairs. Interventions that decrease barriers to mobility and participation can have a significant effect on an individual's perceived quality of life (QOL). This study uses a qualitative research methodology comprised of a series of semi-structured interviews to determine the effects on perceived QOL of an implanted 8-channel functional electrical stimulation (FES) system for standing after SCI. The results reveal that individuals with SCI currently using an implanted FES standing system perceived significant improvements in QOL related to the neuroprosthesis. Implanted neuroprostheses for standing have the potential to improve QOL for veterans living with SCI.

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

    DEFF Research Database (Denmark)

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

    1991-01-01

    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......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......, 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...

  10. [Morphological and numerical studies of the stress compatibility of patella implants].

    Science.gov (United States)

    Lengsfeld, M; Weiss, H; Kienapfel, H

    1992-10-01

    Failure of total knee arthroplasty is relatively often caused by problems of the patellofemoral replacement. The purpose of this study was to analyze the distribution of stresses within an anatomical patella and the changes in stress distribution after patellar resurfacing with a Miller-Galante I patellar implant using two- and three dimensional finite element models (FEM). To assess validity, FEM results were compared with morphological findings from contact radiographs and densitographs. Internal orientation of bone trabeculae is in good agreement with the orientation of theoretically calculated principal stresses. Almost unchanged principal tensile stresses after implantation, together with the lack of extreme stress peaks within the cancellous bone ensure stress compatibility of the implant. In the case of a firmly seated implant with good bone ingrowth, increased von Mises stresses are found near the fixation peg/plate junction. Their relevance for improved bone ingrowth near this part of the interface is emphasized. At the same time, material failure at the peg/plate junction can be better understood. An analysis of the early postoperative period assuming nonlinear interface conditions failed to demonstrate an uniform distribution of normal and tangential interface forces.

  11. Cyclosporine-a and bone density around titanium implants: a histometric study in rabbits

    Directory of Open Access Journals (Sweden)

    Celso Eduardo Sakakura

    2011-06-01

    Full Text Available Aim: Cyclosporine A (CsA is an immunosuppressive agent commonly used to prevent organ transplantation rejection. It has been demonstrated that CsA may negatively affect osseointegration around dental implants. Therefore, the aim of this study was to evaluate the effect of CsA administration on bone density around titanium dental implants. Materials and Methods: Fourteen New Zealand rabbits were randomly divided into 2 groups with seven animals each. The test group (CsA received daily subcutaneous injection of CsA (10mg/kg body weight and the control group (CTL received saline solution by the same route of administration. Three days after the beginning of immunosuppressive therapy, one machined dental implant (7.00 mm in lenght and 3.75 mm in diameter was inserted bilaterally at the region of the tibial methaphysis. After 4 and 8 weeks the animals were sacrificed and the histometrical procedures were performed to analyse the bone density around the first four threads of the coronal part of the implant. Results: A significant increase in the bone density was observed from the 4- to the 8 week-period in the control group (37.41% + 14.85 versus 58.23% + 16.38 – p < 0.01. In contrast, bone density consistently decreased in the test group overtime (46.31% + 17.38 versus 16.28 + 5.08 – p <0.05. In the 8-week period, there was a significant difference in bone density between the control and the test groups (58.23 + 16.38 eand16.28 + 5.08 – p= 0.001. Conclusion: Within the limits of this study, long-term CsA administration may reduce bone density around titanium dental implants during the osseointegration process.

  12. Transradial artery Palmaz-Schatz coronary stent implantation: results of a single-center feasibility study.

    Science.gov (United States)

    Kiemeneij, F; Laarman, G J

    1995-07-01

    The purpose of this study was to evaluate the feasibility and safety of implantation of unsheathed Palmaz-Schatz coronary stents introduced via the radial artery. Anticoagulation after coronary stenting carries the risk of vascular complications if large-bore guiding catheters are introduced via the femoral artery. These complications have serious local sequelae and lead to suboptimal anticoagulation and prolonged hospitalization. By combining 6F guiding catheters and low-profile dilatation catheters mounted with Palmaz-Schatz stents, smaller vessels such as the radial artery can be selected as the entry site. It is hypothesized that with this technique major puncture site-related complications rarely occur because hemostasis is easily achieved and because no veins and nerves are near this artery. With the double blood supply to the hand, radial artery occlusion is well tolerated. In 100 consecutive patients, stent implantation was attempted for 122 lesions in 104 vessels. Immediately after stent implantation and final angiography, the introducer sheath was withdrawn and intense anticoagulation and mobilization initiated. The radial artery puncture site was studied by two-dimensional and Doppler ultrasound. Successful stent implantation via the radial artery was achieved in 96 patients. In 2 patients, arterial puncture failed but was followed by successful stenting via another entry site. In 1 patient, stent implantation was achieved with a stent delivery system via the femoral artery after a failed attempt to cross the lesion with a bare stent via the radial approach, complicated by groin bleeding requiring transfusions and vascular surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Sherlock: Scalable Fact Learning in Images

    OpenAIRE

    Elhoseiny, Mohamed; Cohen, Scott; Chang, Walter; Price, Brian; Elgammal, Ahmed

    2015-01-01

    We study scalable and uniform understanding of facts in images. Existing visual recognition systems are typically modeled differently for each fact type such as objects, actions, and interactions. We propose a setting where all these facts can be modeled simultaneously with a capacity to understand unbounded number of facts in a structured way. The training data comes as structured facts in images, including (1) objects (e.g., $$), (2) attributes (e.g., $$), (3) actions (e.g., $$), and (4) in...

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

    Science.gov (United States)

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

    2011-09-01

    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.

  15. The effects of surgical preparation techniques and implant macro-geometry on primary stability: An in vitro study

    Science.gov (United States)

    Severino, Marco; Rastelli, Claudio; Bernardi, Sara; Caruso, Silvia; Galli, Massimo; Lamazza, Luca; Di Paolo, Carlo

    2017-01-01

    Background The attainment of a good primary stability is a necessary condition to ensure the success of osseointegration in implantology. In type IV cancellous bone, however, it is possible that a reduced primary stability can lead to an increased rate of failure. The aim of this study was therefore to determine, with the help of the resonance frequency (Osstell mentor), which technique of implant site preparation (piezo surgery, conventional, under-preparation, bone compaction, osteodistraction) and macro-geometry is able to improve implant stability in type IV cancellous bone. Material and Methods 10 pig ribs were prepared with a surgical pre-drilled guide, calibrated for a correct implant positioning. On each rib, 5 implant sites (one for each technique) were prepared. Successively, 50 conical implants (Tekka Global D) were inserted and measured with the resonance frequency to evaluate the primary stability. Data collected were analyzed by analysis of variance (ANOVA) to test whether the Implant Stability Quotient (ISQ) values of the five techniques were significantly different. Results The results showed that no significant differences among the ISQ values of the five techniques used were found. Also, no significant differences in the macro-geometry of the two types of compared implants were observed. However, the macro-geometry of Tekka implants, characterized by a double condensing thread, seems to provide greater ISQ values than those of single thread implants when using the same technique. Conclusions In light of these preliminary data, it is conceivable that in cases of reduced stability, such as those occurring with a type IV bone, all means ameliorating the primary stability and accelerating the osseointegration can be utilized. Key words:Implant primary stability, resonance frequency analysis, implant site preparation. PMID:28160577

  16. A Prospective, Longitudinal Study of US Children Unable to Achieve Open-Set Speech Recognition Five Years after Cochlear Implantation

    Science.gov (United States)

    Barnard, JM; Fisher, LM; Johnson, KC; Eisenberg, LS; Wang, NY; Quittner, AL; Carson, CM; Niparko, JK

    2015-01-01

    Objective To identify characteristics associated with inability to progress to open-set speech recognition in children who are 5 years post cochlear implantation. Study Design Prospective, longitudinal and multidimensional assessment of auditory development over 5 years. Setting Six tertiary cochlear implant (CI) referral centers in the US. Patients Children with severe-to-profound hearing loss who underwent implantation before age 5 years enrolled in the Childhood Development after Cochlear Implant (CDaCI) study, categorized by level of speech recognition ability. Intervention(s) Cochlear implantation prior to 5 years of age and annual assessment of emergent speech recognition skills. Main outcome measure(s) Progression to open-set speech recognition by 5 years after implantation. Results Less functional hearing prior to implantation, older age at onset of amplification, lower maternal sensitivity to communication needs, minority status, and complicated perinatal history were associated with inability to obtain open set speech recognition by 5 years. Conclusions Characteristics of a subpopulation of children with CIs that were associated with an inability to achieve open-set speech recognition after 5 years of CI experience were investigated. These data distinguish pediatric CI recipients at risk for poor auditory development and highlight areas for future interventions to enhance support of early implantation. PMID:25700015

  17. Psychological effects of implantable cardioverter defibrillator shocks. A review of study methods

    OpenAIRE

    Manzoni, Gian Mauro; Castelnuovo, Gianluca; Compare, Angelo; Pagnini, Francesco; Essebag, Vidal; Proietti, Riccardo

    2015-01-01

    Background: The implantable cardioverter defibrillator (ICD) saves lives but clinical experience suggests that it may have detrimental effects on mental health. The ICD shock has been largely blamed as the main offender but empirical evidence is not consistent, perhaps because of methodological differences across studies. Objective: To appraise methodologies of studies that assessed the psychological effects of ICD shock and explore associations between methods and results. Data Sources...

  18. Psychological effects of implantable cardioverter defibrillator shocks. A review of study methods.

    OpenAIRE

    Gian Mauro eManzoni; Gianluca eCastelnuovo; Angelo eCompare; Francesco ePagnini; Vidal eEssebag; Riccardo eProietti

    2015-01-01

    BackgroundThe implantable cardioverter defibrillator (ICD) saves lives but clinical experience suggests that it may have detrimental effects on mental health. The ICD shock has been largely blamed as the main offender but empirical evidence is not consistent, perhaps because of methodological differences across studies. ObjectiveTo appraise methodologies of studies that assessed the psychological effects of ICD shock and explore associations between methods and results. Data Sources A compreh...

  19. Facts about Hib Disease. ARC Facts.

    Science.gov (United States)

    Association for Retarded Citizens, Arlington, TX.

    The fact sheet provides basic information about Hib Disease in young children, which may involve a bacterial meningitis causing mental retardation, hearing loss, partial blindness, speech disorders, partial paralysis, behavioral problems, or seizures. Stressed is prevention of Hib Disease through immunization. The question and answer format…

  20. Facts about Hib Disease. ARC Facts.

    Science.gov (United States)

    Association for Retarded Citizens, Arlington, TX.

    The fact sheet provides basic information about Hib Disease in young children, which may involve a bacterial meningitis causing mental retardation, hearing loss, partial blindness, speech disorders, partial paralysis, behavioral problems, or seizures. Stressed is prevention of Hib Disease through immunization. The question and answer format…

  1. 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

  2. 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.

  3. A study of the structural properties of GaN implanted by various rare-earth ions

    Science.gov (United States)

    Mackova, A.; Malinský, P.; Sofer, Z.; Šimek, P.; Sedmidubský, D.; Mikulics, M.; Wilhelm, R. A.

    2013-07-01

    GaN layers with crystallographic orientation, grown by low-pressure metal-organic vapour-phase epitaxy (MOVPE) on c-plane sapphire substrates, were implanted with 200 and 400 keV Sm+, Tm+, Eu+, Tb+ and Ho+ ions at fluencies of 1 × 1015-1 × 1016 cm-2. The composition of the ion-implanted layers and concentration profiles of the implanted atoms were studied by Rutherford Back-Scattering spectrometry (RBS). The profiles were compared to SRIM 2008 simulations. The structural properties of the ion-implanted layers were characterised by RBS-channelling and Raman spectroscopy. Changes in the surface morphology caused by the ion implantation were examined by Atomic Force Microscopy (AFM). A structural analysis showed a high disorder of the atoms close to the amorphised structure at the surface layer above an implantation fluence of 5 × 1015 cm-2 while lower disorder density was observed in the bulk according to the projected range of 400 keV ions. The post-implantation annealing induced significant changes only in the Sm and Eu depth profiles; a diffusion of rare-earths implanted at a fluence of 5 × 1015 cm-2 to the surface was observed. The annealing caused the reconstruction of the surface layer accompanied by surface-roughness enhancement.

  4. 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....... The medians for the TiO2-blasted screw and cylindrical implants were > 150 Ncm and 105 Ncm, respectively, while the values for the m.p. implants were 60 Ncm and 35 Ncm, respectively. The SEM investigation demonstrated a high irregularity of the TiO2-blasted surface compared to the machined surface. The Ra...... and Rz values for surface roughness were higher for the TiO2-blasted implants than for the normal m.p. implants. Histomorphometrically, the arithmetic mean of the direct bone-implant contact fraction was 69%. There was no significant difference in direct bone-implant contact length fraction between TiO2...

  5. Investigation of the influence of design details on short implant biomechanics using colorimetric photoelastic analysis: a pilot study

    Directory of Open Access Journals (Sweden)

    João César Zielak

    Full Text Available Introduction : The clinical survival of a dental implant is directly related to its biomechanical behavior. Since short implants present lower bone/implant contact area, their design may be more critical to stress distribution to surrounding tissues. Photoelastic analysis is a biomechanical method that uses either simple qualitative results or complex calculations for the acquisition of quantitative data. In order to simplify data acquisition, we performed a pilot study to demonstrate the investigation of biomechanics via correlation of the findings of colorimetric photoelastic analysis (stress transition areas; STAs of design details between two types of short dental implants under axial loads. Methods Implants were embedded in a soft photoelastic resin and axially loaded with 10 and 20 N of force. Implant design features were correlated with the STAs (mm2 of the colored fringes of colorimetric photoelastic analysis. Results Under a 10 N load, the surface area of the implants was directly related to STA, whereas under a 20 N load, the surface area and thread height were inversely related to STA. Conclusion A smaller external thread height seemed to improve the biomechanical performance of the short implants investigated.

  6. Clinical and radiological investigations of mandibular overdentures supported by conventional or mini-dental implants: A 2-year prospective follow-up study.

    Science.gov (United States)

    Temizel, Sonay; Heinemann, Friedhelm; Dirk, Cornelius; Bourauel, Christoph; Hasan, Istabrak

    2017-02-01

    Conventional dental implants are not applicable in the mandibular interforaminal region if bone volume is limited. Mini-dental implants offer an alternative means of supporting mandibular overdentures in a narrow residual ridge, without additional surgery. The purpose of this nonrandomized clinical trial was to compare the ability of mini-dental implants with that of conventional dental implants in supporting mandibular overdentures during a 2-year clinical follow-up. Bone quality, bone resorption, implant stability, and oral health were assessed radiographically. A total of 32 participants with edentulism were included. Twenty-two participants (99 implants) received 4 to 5 mini-dental implants (diameter: 1.8-2.4 mm; length: 13-15 mm, study group), and 10 participants (35 implants) received 2 to 4 conventional dental implants (diameter: 3.3-3.7 mm; length: 11-13 mm, control group). The selection of the participants in the study or control group was based on the available bone volume in the mandible. The selection was not randomized. The density of cortical bone thickness was measured in Hounsfield units (HU) from computed tomography data, and patients were followed for 2 years. The participants were examined 3, 6, 12, and 24 months after surgery. Primary stability immediately after the insertion of dental implants (Periotest), secondary stability 6 months after implantation, modified plaque, bleeding on probing indices, and probing depth were measured and analyzed statistically (α=.05). The mean HU value 6 months after implantation in the participants who received mini-dental implants was significantly (P=.035) higher (1250 HU) than that in the participants who received conventional dental implants (1100 HU). The probing depths around the conventional dental implants (1.6 and 1.8 mm, respectively) were significantly higher than those around the mini-dental implants (1.3 and 1.2 mm, respectively) 12 and 24 months after surgery, respectively (Pdental implants were

  7. Immediate implant placement using a biodegradable barrier, polyhydroxybutyrate-hydroxyvalerate reinforced with polyglactin 910. An experimental study in dogs

    DEFF Research Database (Denmark)

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

    1994-01-01

    extracted bilaterally. Each dog had 4 Astra Dental Implants placed directly into the fresh extraction sockets. The top of the fixtures was placed at the same level as the top of the buccal cortical bone. The two implants in the right side were covered with the hydrolyzable polyester material......The purpose of this study was to evaluate the use of a biodegradable membrane of polyhydroxybutyrate-hydroxyvalerate copolymer reinforced with polyglactin 910 fibers, as an occlusive barrier over implants placed into fresh extraction sockets. Ten dogs had the 3rd and 4th mandibular premolars...... (polyhydroxybutyrate-hydroxyvalerate reinforced with polyglactin 910 fibers; PHB-HV/PG), and the 2 implants in the left side were controls without occlusive membranes. Soft tissue dehiscences were registered for half of the implants in the test side but were not noted in the control side. The histomorphological...

  8. Bone reactions adjacent to titanium implants subjected to static load of different duration. A study in the dog (III)

    DEFF Research Database (Denmark)

    Gotfredsen, K; Berglundh, T; Lindhe, J

    2001-01-01

    The aim of the present experiment was to study the effect of a long-standing lateral static load on the peri-implant bone. Three beagle dogs were used. The mandibular premolars were extracted and 12 weeks later 3 titanium implants (ITI(R) Dental Implant System) were installed in each quadrant....... Crowns were fitted to all implants 12 weeks after the installation procedure. The anterior and central crowns were fused and connected to the posterior crown by an expansion screw. In the right side of the mandible, the expansion screws were activated every 2 weeks during a 46-week period. During...... the last 10 weeks of this period, an expansion force similar to that of the right side was applied in the left. The animals were sacrificed and block biopsies of each implant site harvested and prepared for histological analysis. Sites subjected to 10 weeks or 46 weeks of lateral load had a similar (i...

  9. Evaluation of peri-implant soft tissue and bone levels around early loaded implant in restoring single missing tooth: A clinico-radiographic study

    Science.gov (United States)

    Bhardwaj, Isha; Bhushan, Anoop; Baiju, Chandrababu Sudha; Bali, Shweta; Joshi, Vaibhav

    2016-01-01

    Background: One-stage nonsubmerged protocol which can achieve success rates comparable to implants placed in a two-staged submerged procedure also the preconditions for periimplant bone regeneration has lead to more refined concepts of implant loading. Materials and Methods: Twenty sites with single missing tooth were included in this study. Clinical parameters included sulcus bleeding index (sBI), probing pocket depth (PD), and papilla index (PI) and radiographic parameters included crestal bone level were assessed for a period of 9 months. Results: The crestal bone loss showed mean value ranging from baseline 0.25 ± 0.11 to 0.31 ± 0.08 at 3 weeks, to 0.67 ± 0.13 at 3 months, to 0.85 ± 0.09 at 6 months, and to 0.88 ± 0.12 at 9 months. Probing PD, the mean value for probing PD at 3 weeks 1.20 ± 0.83, 3 months 1.60 ± 1.1, at 6 months 1.40 ± 1.14, and at 9 months 1.20 ± 1.0. sBI, mean value for sBI at 3 weeks 0.00 ± 0.00, 3 months 0.3 ± 0.11, at 6 months 0.09 ± 0.25, and at 9 months 0.08 ± 0.24. PI, showed a significant difference among at different points of time with P = 0.000. Conclusion: The dental implants showed <1 mm of crestal bone loss at 9 months follow-up, clinically significant marginal bone loss occurred between the time of implant placement and 3 months. Subsequent to that, bone loss observed around the implant up to 9 months was minimal. The periimplant soft tissue maturity was maintained throughout the study. PMID:27041836

  10. Rutherford backscattering and channelling studies of erbium implanted SIMOX refid="FN1">**SIMOX: separation by implanted oxygen. structures

    Science.gov (United States)

    Zhang, Jingping; Tang, Y. S.; Hemment, P. L. F.; Sealy, B. J.

    1990-04-01

    The behaviour of 250 keV 166Er + implanted into SIMOX structures has been investigated by Rutherford backscattering and channelling analysis. The implantation doses were 1.5 ×10 14 cm -2 and 1.5 × 10 15 cm -2. Both conventional furnace and rapid therm annealing were carried out in the temperature range 600°C-1100°C. Regrowth of the amorphized silicon and redistribution of the erbium were found to be strongly influenced by the status of the damaged layer. Different regrowth processes of the completely damaged silicon overlayer were suggested respectively for conventional furnace and rapid thermal annealing. It is found that the regrowth rate increases rapidly when the temperature is higher than 900° C in both cases. The redistribution of the erbium atoms was controlled by the regrowth boundary between the damaged and the recrystallized silicon.

  11. Estudio de asociación entre enfermedades sistémicas y el fracaso de implantes dentales Study of association between systemic diseases and dental implant failure

    Directory of Open Access Journals (Sweden)

    J Domínguez

    2013-04-01

    , genero y el habito de fumar.Since the beginning of oral implant surgery it has been recommended to exclude or limit certain patients with health issues or smoking habits. The chronic non-communicable diseases are not considered an absolute contraindication to the use of oral implants, but the type of disease should be evaluated in detail, as a potential risk that could affect the process of osseointegration. There are certain systemic conditions, such as osteoporosis, cardiovascular disease, diabetes mellitus, and hypothyroidism, as well as the habit of smoking, that affect the success, survival or failure of the implants. The purpose of the investigation is to determine whether there is an association between the failure of dental implants and systemic diseases in the population of patients undergoing dental implant surgery of San José de Santiago de Chile Hospital. We conducted a retrospective observational study and the variables studied were systemic diseases (osteoporosis, hypertension, diabetes, and hypothyroidism and the criteria used to assess the health of implants were those of the International Congress of Oral Implantology of Pisa, where "failure" is the term used for implants requiring removal or that were already lost. These variables were recorded from the clinical record and during a clinical examination, in a data collection sheet. This allowed to describe variables and their distribution, and then to analyze the data to find statistically valid evidence. For this study we can conclude that the analysis of each of the variables such as systemic hypertension or ASA II, have an association with the failure of dental implants, but not osteoporosis, hypothyroidism, diabetes, age, nutritional status, gender and cigarette smoking.

  12. The use of the FACT-H&N (v4) in clinical settings within a developing country: a mixed method study.

    Science.gov (United States)

    Bilal, Sobia; Doss, Jennifer Geraldine; Rogers, Simon N

    2014-12-01

    In the last decade there has been an increasing awareness about 'quality of life' (QOL) of cancer survivors in developing countries. The study aimed to cross-culturally adapt and validate the FACT-H&N (v4) in Urdu language for Pakistani head and neck cancer patients. In this study the 'same language adaptation method' was used. Cognitive debriefing through in-depth interviews of 25 patients to assess semantic, operational and conceptual equivalence was done. The validation phase included 50 patients to evaluate the psychometric properties. The translated FACT-H&N was easily comprehended (100%). Cronbach's alpha for FACT-G subscales ranged from 0.726 - 0.969. The head and neck subscale and Pakistani questions subscale showed low internal consistency (0.426 and 0.541 respectively). Instrument demonstrated known-group validity in differentiating patients of different clinical stages, treatment status and tumor sites (p FACT summary scales correlated strongly with each other (r > 0.75) and showed convergent validity (r > 0.90), with little discriminant validity. Factor analysis revealed 6 factors explaining 85.1% of the total variance with very good (>0.8) Kaiser-Meyer-Olkin and highly significant Bartlett's Test of Sphericity (p FACT-H&N into Urdu language showed adequate reliability and validity to be incorporated in Pakistani clinical settings for head and neck cancer patients. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  13. Personal semantics: Is it distinct from episodic and semantic memory? An electrophysiological study of memory for autobiographical facts and repeated events in honor of Shlomo Bentin.

    Science.gov (United States)

    Renoult, Louis; Tanguay, Annick; Beaudry, Myriam; Tavakoli, Paniz; Rabipour, Sheida; Campbell, Kenneth; Moscovitch, Morris; Levine, Brian; Davidson, Patrick S R

    2016-03-01

    Declarative memory is thought to consist of two independent systems: episodic and semantic. Episodic memory represents personal and contextually unique events, while semantic memory represents culturally-shared, acontextual factual knowledge. Personal semantics refers to aspects of declarative memory that appear to fall somewhere in between the extremes of episodic and semantic. Examples include autobiographical knowledge and memories of repeated personal events. These two aspects of personal semantics have been studied little and rarely compared to both semantic and episodic memory. We recorded the event-related potentials (ERPs) of 27 healthy participants while they verified the veracity of sentences probing four types of questions: general (i.e., semantic) facts, autobiographical facts, repeated events, and unique (i.e., episodic) events. Behavioral results showed equivalent reaction times in all 4 conditions. True sentences were verified faster than false sentences, except for unique events for which no significant difference was observed. Electrophysiological results showed that the N400 (which is classically associated with retrieval from semantic memory) was maximal for general facts and the LPC (which is classically associated with retrieval from episodic memory) was maximal for unique events. For both ERP components, the two personal semantic conditions (i.e., autobiographical facts and repeated events) systematically differed from semantic memory. In addition, N400 amplitudes also differentiated autobiographical facts from unique events. Autobiographical facts and repeated events did not differ significantly from each other but their corresponding scalp distributions differed from those associated with general facts. Our results suggest that the neural correlates of personal semantics can be distinguished from those of semantic and episodic memory, and may provide clues as to how unique events are transformed to semantic memory.

  14. SU-E-J-257: Image Artifacts Caused by Implanted Calypso Beacons in MRI Studies

    Energy Technology Data Exchange (ETDEWEB)

    Amro, H; Chetty, I; Gordon, J; Wen, N [Henry Ford Health System, Detroit, MI (United States)

    2014-06-01

    Purpose: The presence of Calypso Beacon-transponders in patients can cause artifacts during MRI imaging studies. This could be a problem for post-treatment follow up of cancer patients using MRI studies to evaluate metastasis and for functional imaging studies.This work assesses (1) the volume immediately surrounding the transponders that will not be visualized by the MRI due to the beacons, and (2) the dependence of the non-visualized volume on beacon orientation, and scanning techniques. Methods: Two phantoms were used in this study (1) water filled box, (2) and a 2300 cc block of pork meat. Calypso beacons were implanted in the phantoms both in parallel and perpendicular orientations with respect to the MR scanner magnetic field. MR image series of the phantom were obtained with on a 1.0T high field open MR-SIM with multiple pulse sequences, for example, T1-weighted fast field echo and T2-weighted turbo spin echo. Results: On average, a no-signal region with 2 cm radius and 3 cm length was measured. Image artifacts are more significant when beacons are placed parallel to scanner magnetic field; the no-signal area around the beacon was about 0.5 cm larger in orthogonal orientation. The no-signal region surrounding the beacons slightly varies in dimension for the different pulse sequences. Conclusion: The use of Calypso beacons can prohibit the use of MRI studies in post-treatment assessments, especially in the immediate region surrounding the implanted beacon. A characterization of the MR scanner by identifying the no-signal regions due to implanted beacons is essential. This may render the use of Calypso beacons useful for some cases and give the treating physician a chance to identify those patients prior to beacon implantation.

  15. A failure study of a locking compression plate implant

    Directory of Open Access Journals (Sweden)

    Nirajan Thapa

    2015-04-01

    Full Text Available In this case study a failed locking compression plate was investigated. Such plating systems are used to provide the stability to fractured bone and fixation. The locking compression plate had been separated in two pieces. One of the fracture surfaces from the failed component was investigated for surface topographical features. The visual, optical and scanning electron microscopy results indicated the presence of beach marks, intermetallic inclusions, corrosion pits and striations indicating fatigue crack propagation and overload failure. Some corrosion damage also was documented on the fractography. This case study shows that corrosion may have initiated fatigue crack which grew by the activities of daily living causing the failure.

  16. Histological evaluation of the biocompatibility of polyurea crosslinked silica aerogel implants in a rat model: a pilot study.

    Directory of Open Access Journals (Sweden)

    Firouzeh Sabri

    Full Text Available BACKGROUND: Aerogels are a versatile group of nanostructured/nanoporous materials with physical and chemical properties that can be adjusted to suit the application of interest. In terms of biomedical applications, aerogels are particularly suitable for implants such as membranes, tissue growth scaffolds, and nerve regeneration and guidance inserts. The mesoporous nature of aerogels can also be used for diffusion based release of drugs that are loaded during the drying stage of the material. From the variety of aerogels polyurea crosslinked silica aerogels have the most potential for future biomedical applications and are explored here. METHODOLOGY: This study assessed the short and long term biocompatibility of polyurea crosslinked silica aerogel implants in a Sprague-Dawley rat model. Implants were inserted at two different locations a subcutaneously (SC, at the dorsum and b intramuscularly (IM, between the gluteus maximus and biceps femoris of the left hind extremity. Nearby muscle and other internal organs were evaluated histologically for inflammation, tissue damage, fibrosis and movement (travel of implant. CONCLUSION/SIGNIFICANCE: In general polyurea crosslinked silica aerogel (PCSA was well tolerated as a subcutaneous and an intramuscular implant in the Sprague-Dawley rat with a maximum incubation time of twenty months. In some cases a thin fibrous capsule surrounded the aerogel implant and was interpreted as a normal response to foreign material. No noticeable toxicity was found in the tissues surrounding the implants nor in distant organs. Comparison was made with control rats without any implants inserted, and animals with suture material present. No obvious or noticeable changes were sustained by the implants at either location. Careful necropsy and tissue histology showed age-related changes only. An effective sterilization technique for PCSA implants as well as staining and sectioning protocol has been established. These studies

  17. Transverse maxillary and mandibular growth during and after Bionator therapy: study with metallic implants

    Directory of Open Access Journals (Sweden)

    André da Costa Monini

    2013-06-01

    Full Text Available INTRODUCTION: This study evaluated posteroanterior cephalograms before and after treatment and long term follow-up of Class II division 1 patients treated with bionator. OBJECTIVE: The objective was to demonstrate the transverse growth of maxilla and mandible during and after bionator therapy. METHODS: Measurement of transverse dimensions between posterior maxillary and mandibular implants, as well as the distances between the buccal, gonial and antegonial points were recorded. Measurements were analyzed at three periods: T1 = before bionator therapy, T2 = after bionator therapy and T3 = 5.74 years after T2. RESULTS: There was statistically significant transverse increase due to growth and/or treatment for all variables, except for the distance between the anterior maxillary implants. CONCLUSIONS: During the study period only the anterior maxillary area did not show transverse growth.

  18. Guided implant surgery with modification of the technique involving the raising of a semicircular miniflap: a preliminary study.

    Science.gov (United States)

    Peñarrocha, María; Viña, José; Maestre, Laura; Peñarrocha, David; Balaguer, José

    2012-09-01

    An evaluation is made of pain, swelling and peri-implant attached mucosal width after implant-based rehabilitation involving guided surgery and a modification of the technique with the raising of a semicircular miniflap, in single and partial replacements. A case-control study was carried out. The study group consisted of 12 patients with the placement of 19 implants using a guided surgery and miniflap technique. The control group consisted of 12 patients with the placement of 22 implants using the conventional technique. Each patient scored postoperative swelling and pain by means of a visual analog scale (VAS). Attached vestibular mucosa width was evaluated 12 weeks after implant placement. Twelve operations were carried out in each group. Immediate aesthetics were established for all implants of the study group. One implant failed in each group. Maximum pain was recorded after 6 hours in both groups (mean VAS score 4 and 4.9 in the study and control group, respectively). Maximum swelling was recorded after 24 hours (mean VAS score 2.5) in the study group and on the second day (mean VAS score 3.4) in the control group. The mean attached vestibular mucosa width was 2.9 mm in the study group and 3.2 mm in the control group. In this preliminary study, guided implant surgery with a semicircular miniflap in single and partial replacements resulted in slightly less postoperative pain and swelling than with the conventional implant technique. The attached vestibular mucosa width was greater in the control group, though the differences were very small.

  19. Evaluation of MBEC™-HTP biofilm model for studies of implant associated infections.

    Science.gov (United States)

    Coraça-Hubér, Debora C; Fille, Manfred; Hausdorfer, Johann; Pfaller, Kristian; Nogler, Michael

    2012-07-01

    The bacteria in implant-related infections can evade host defenses by forming biofilms. The more we understand biofilm behavior, the better we can fight against then clinically. In vitro models for biofilms allow tests simulating in vivo conditions. In this study we evaluated the Minimum Biofilm Eradication Concentration-High Throughput Plates (MBEC™-HTP) as biofilm in vitro model for studies of implant associated infections. Staphylococcus aureus and Staphylococcus epidermidis biofilms were grown on MBEC™-HTP. To ensure the biofilm formation, antibiotic susceptibility tests and scanning electron microscopy (SEM) was carried out. Susceptibility tests were carried out using gentamicin, vancomycin, rifampicin, fosfomycin, clindamycin, and linezolid. Colony forming units counting were carried out. Minimal inhibitory concentration (MIC) and biofilm inhibitory concentration (BIC) were estimated. The CFU counting showed potency of rifampicin and daptomycin against S. epidermidis biofilms and rifampicin against S. aureus biofilms. SEM images showed proteic material in contact with cells. The differences between BIC and MIC demonstrated the biofilm formation as well as the SEM images. Rifampicin and daptomycin are good choices against biofilm related infections. Moreover, after suggested modifications, the model used in this study is eligible to further studies of implant associated infections. Copyright © 2012 Orthopaedic Research Society.

  20. Vowel intelligibility in children with cochlear implants: An acoustic and articulatory study.

    Science.gov (United States)

    Turgeon, Christine; Trudeau-Fisette, Pamela; Fitzpatrick, Elizabeth; Ménard, Lucie

    2017-10-01

    In child cochlear implant (CI) users, early implantation generally results in highly intelligible speech. However, for some children developing a high level of speech intelligibility may be problematic. Studies of speech production in CI users have principally been based on perceptual judgment and acoustic measures. Articulatory measures, such as those collected using ultrasound provide the opportunity to more precisely evaluate what makes child CI users more intelligible. This study investigates speech production and intelligibility in children with CI using acoustic and articulatory measures. Ten children with unilateral or bilateral CIs and 13 children with normal hearing (NH) participated in the study. Participants repeated five English vowels (/a/, /e/, /i/, /o/, /u/) with and without auditory feedback. Ultrasound was used to capture tongue positions and acoustic signals were recorded simultaneously. The results showed that, despite quite similar acoustic results, the two speaker groups made different use of the tongue to implement vowel contrasts. Indeed, the tongue position was lower in the feedback OFF condition than the feedback ON condition for all participants, but the magnitude of this difference was larger for CI users than for their NH peers. This difference led to diminished intelligibility scores for CI users. This study shows the limitation of acoustic measurements alone and demonstrates how the use of articulatory measurements can explain intelligibility patterns. Moreover, our results show that when cochlear implantation occurs early in life and auditory feedback is available, CI users' intelligibility is comparable to that of their NH peers. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Revision of Minimally Invasive Sacroiliac Joint Fixation: Technical Considerations and Case Studies Using Decortication and Threaded Implant Fixation

    Science.gov (United States)

    Fielding, Louis C

    2017-01-01

    symptomatic pseudoarthrosis after SIJ fixation surgery can be successfully revised with decortication, grafting and fixation with threaded implants utilizing MI surgical techniques. Implant trajectory is an important consideration for primary or revision MIS SIJ fusion. Studies with longer-term follow-up of both primary and revision procedures are needed to further understand fusion rates for both primary and revision procedures utilizing both triangular and threaded implant systems.

  2. Study on Treating Glioblastoma with 125I Seed Implantation during Operations

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    OBJECTIVE To evaluate the therapeutic efficacy of treating glioblastoma with interstitial irradiation using radioactive seeds.METHODS First, the tumor was removed as completely as possible under an operating microscope. Then 125I seeds which had been selected were implanted in the tumor bed followed by routine radiotherapy after the operation. The time of progression (TTP) and overall survival (OS) of the patients were recorded, and statistically compared with patients who had received only surgery and radiotherapy for glioblastoma during the same period.RESULTS Nineteen patients, who were diagnosed with glioblastoma for the first time, with a mean age of 51.2 years, were involved in this study.Radioactive seeds (8~20) were implanted into the tumor bed after tumorectomy with a mean surrounding therapeutic dose of 31.6 Gy, followed by an external irradiation dose of 42~54 Gy. The average TTP in the group with implanted seeds was 42.1±2.4 w (95% confidence interval, 37.2~46.5 w), and 27.1±2.7 w (95% confidence interval, 24.3~31.8 w) in the control group. The average OS was 66.3±3.2 w (95% confidence interval, 61.9~70.4 w) and 47.7±2.6 w (95% confidence interval, 44.4~50.5 w), respectively. Statistical analysis showed there was a significant difference between two groups.CONCLUSION The survival time of patients with glioblastoma can be prolonged through radioactive seed implantation at the time of operation.This therapeutic method can rapidly reduce the tumor volume with a minimum number of seeds to avoid excessive radiation exposure. Because of some shortcomings of this study, such as a small number of patients, and because implantation was performed under the naked eye so that the seed alignment could not be verified accurately, the experience of combining implantation of seeds with external irradiation needs to be investigated further.

  3. Cosmogenic and implanted radionuclides studied by selective etching of lunar soils

    CERN Document Server

    Jull, A J T; McHargue, L R; Burr, G S; Donahue, D J

    2000-01-01

    We have made new measurements of the concentrations of sup 1 sup 4 C and sup 1 sup 0 Be in lunar surface soils. We discuss the results of these new studies based on different acid etching methods, which provide useful information for future experiments. We also discuss the implications of these results for the production of these radionuclides by galactic and solar cosmic radiation, and the direct implantation of solar-energetic particles into lunar surface material.

  4. Histologic studies on osseointegration: soft tissues response to implant surfaces and components. A review.

    Science.gov (United States)

    Piattelli, Adriano; Pontes, Ana Emilia Farias; Degidi, Marco; Iezzi, Giovanna

    2011-01-01

    It is important to clarify the potential response of different types of cells to different implant materials and topographies. Thus, in vitro studies are performed using cell cultures, in order to evaluate, among other characteristics, the morphology, orientation, proliferation and adhesion of the cells. Histology evaluation are performed in animals or humans to describe the physiological response to different surfaces. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Study on the cytotoxicity and chromosome aberration following implantation of sea coral in rabbits

    Directory of Open Access Journals (Sweden)

    Kannan TP

    2006-03-01

    Full Text Available Coral has been used as a bone substitute in many experimental studies. It has been proven to be biocompatible, biodegradable and easy to handle: and it has not been found to cause any inflammatory responses. The present study was undertaken to determine the cytotoxicity in terms of mitotic index as well as the clastogenic effect (chromosome aberration of sea coral implantation in rabbits. The animals comprised of five male adult healthy New Zealand White (Oryctolagus cuniculus rabbits. The biomaterial, sea coral granules used in this study was obtained from Porites species and processed by the tissue bank of Universiti Sains Malaysia, Health Campus, Kubang Kerian, Malaysia. The blood samples were collected twice from the rabbits, once before the implantation of the sea coral granules (which acted as the control and the other, one week after the implantation (which acted as the treatment and lymphocyte cultures were set up. The cultures were then harvested and the chromosomes were prepared for analysis. The diploid number of chromosomes in the rabbits (Oryctolagus cuniculus was found to be 44. Mean mitotic indices of 3.84 ± 0.54 per cent and 3.76 ± 0.23 per cent were obtained before and after implantation of sea coral granules respectively. There were no structural or numerical chromosomal aberrations observed in both the cases. The mitotic index values and chromosomal analyses in this preliminary study carried out indicate that the biomaterial, sea coral granules is non-cytotoxic and non-clastogenic under the present test conditions.

  6. Bilateral Versus Unilateral Cochlear Implants in Children: A Study of Spoken Language Outcomes

    OpenAIRE

    2014-01-01

    Objectives: Although it has been established that bilateral cochlear implants (CIs) offer additional speech perception and localization benefits to many children with severe to profound hearing loss, whether these improved perceptual abilities facilitate significantly better language development has not yet been clearly established. The aims of this study were to compare language abilities of children having unilateral and bilateral CIs to quantify the rate of any improvement in language attr...

  7. The impact of CBCT imaging when placing dental implants in the anterior edentulous mandible: a before-after study.

    Science.gov (United States)

    Shelley, A M; Ferrero, A; Brunton, P; Goodwin, M; Horner, K

    2015-01-01

    To evaluate the impact of CBCT imaging when placing dental implants in the anterior edentulous mandible, using a "before-after" study design. Eight dental practitioners, who regularly place dental implants in independent dental practice in the North West of England, were presented with realistic simulations of four edentulous cases. The practitioners were asked to assess case difficulty, select implants and then drill osteotomies in preparation for dental implants in the lower canine regions to support a complete overdenture. In the "before" part of the study, a panoramic and a trans-symphyseal view were available. In the "after" part of the study, a CBCT image was added. Perception of case difficulty, implant selection and the incidence of perforations or "near miss perforations" of the lingual cortical plate were recorded. Two cases were regarded as "regular" and two as "challenging". In challenging cases, the availability of CBCT led practitioners to select narrower implants and to assess cases as more difficult. In the challenging cases only, there were fewer perforations of the lingual cortical plate after the availability of CBCT, but this difference was not statistically significant. There were no perforations in the regular cases either before or after the availability of CBCT. Perception of case difficulty and implant selection are of importance only if they change the outcome for the patient. This study provided weak evidence that CBCT is helpful in avoiding perforations in challenging cases. The availability of CBCT had no impact in regular cases.

  8. Study of Nickel Ion Release in Simulated Body Fluid from C+-IMPLANTED Nickel Titanium Alloy

    Science.gov (United States)

    Shafique, Muhammad Ahsan; Murtaza, G.; Saadat, Shahzad; Zaheer, Zeeshan; Shahnawaz, Muhammad; Uddin, Muhammad K. H.; Ahmad, Riaz

    2016-05-01

    Nickel ion release from NiTi shape memory alloy is an issue for biomedical applications. This study was planned to study the effect of C+ implantation on nickel ion release and affinity of calcium phosphate precipitation on NiTi alloy. Four annealed samples are chosen for the present study; three samples with oxidation layer and the fourth without oxidation layer. X-ray diffraction (XRD) spectra reveal amorphization with ion implantation. Proton-induced X-ray emission (PIXE) result shows insignificant increase in Ni release in simulated body fluid (SBF) and calcium phosphate precipitation up to 8×1013ions/cm2. Then Nickel contents show a sharp increase for greater ion doses. Corrosion potential decreases by increasing the dose but all the samples passivate after the same interval of time and at the same level of VSCE in ringer lactate solution. Hardness of samples initially increases at greater rate (up to 8×1013ions/cm2) and then increases with lesser rate. It is found that 8×1013ions/cm2 (≈1014) is a safer limit of implantation on NiTi alloy, this limit gives us lesser ion release, better hardness and reasonable hydroxyapatite incubation affinity.

  9. Experience with magnetic resonance imaging of human subjects with passive implants and tattoos at 7 T: a retrospective study.

    Science.gov (United States)

    Noureddine, Yacine; Bitz, Andreas K; Ladd, Mark E; Thürling, Markus; Ladd, Susanne C; Schaefers, Gregor; Kraff, Oliver

    2015-12-01

    Over the last decade, the number of clinical MRI studies at 7 T has increased dramatically. Since only limited information about the safety of implants/tattoos is available at 7 T, many centers either conservatively exclude all subjects with implants/tattoos or have started to perform dedicated tests for selected implants. This work presents our experience in imaging volunteers with implants/tattoos at 7 T over the last seven and a half years. 1796 questionnaires were analyzed retrospectively to identify subjects with implants/tattoos imaged at 7 T. For a total of 230 subjects, the type of local transmit/receive RF coil used for examination, imaging sequences, acquisition time, and the type of implants/tattoos and their location with respect to the field of view were documented. These subjects had undergone examination after careful consideration by an internal safety panel consisting of three experts in MR safety and physics. None of the subjects reported sensations of heat or force before, during, or after the examination. None expressed any discomfort related to implants/tattoos. Artifacts were reported in 52% of subjects with dental implants; all artifacts were restricted to the mouth area and did not affect image quality in the brain parenchyma. Our initial experience at 7 T indicates that a strict rejection of subjects with tattoos and/or implants is not justified. Imaging can be conditionally performed in carefully selected subjects after collection of substantial safety information and evaluation of the detailed exposure scenario (RF coil/type and position of implant). Among the assessed subjects with tattoos, no side effects from the exposure to 7 T MRI were reported.

  10. Histological and biomechanical analysis of porous additive manufactured implants made by direct metal laser sintering: a pilot study in sheep.

    Science.gov (United States)

    Stübinger, Stefan; Mosch, Isabel; Robotti, Pierfrancesco; Sidler, Michéle; Klein, Karina; Ferguson, Stephen J; von Rechenberg, Brigitte

    2013-10-01

    It was the aim of this study to analyze osseointegrative properties of porous additive manufactured titanium implants made by direct metal laser sintering in a sheep model after an implantation period of 2 and 8 weeks. Three different types of implants were placed in the pelvis of six sheep. In each sheep were placed three standard machined (M), three sandblasted and etched (SE), and three porous additive manufactured (AM) implants. Of these three implants (one per type) were examined histologically and six implants were tested biomechanically. Additionally a semiquantitative histomorphometrical and qualitative fluorescent microscopic analysis were performed. After 2 and 8 weeks bone-to-implant-contact (BIC) values of the AM surface (2w: 20.49% ± 5.18%; 8w: 43.91% ± 9.69%) revealed no statistical significant differences in comparison to the M (2w: 20.33% ± 11.50%; 8w: 25.33% ± 4.61%) and SE (2w: 43.67 ± 12.22%; 8w: 53.33 ± 8.96%) surfaces. AM surface showed the highest increase of the BIC between the two observation time points. Considering the same implantation period histomorphometry and fluorescent labelling disclosed no significant differences in the bone surrounding the three implants groups. In contrast Removal-torque-test showed a significant improve in fixation strength (P ≤ 0.001) for the AM (1891.82 ± 308, 44 Nmm) surface after eight weeks in comparison to the M (198.93±88,04 Nmm) and SE (730.08 ± 151,89 Nmm) surfaces. All three surfaces (M, SE, and AM) showed sound osseointegration. AM implants may offer a possible treatment option in clinics for patients with compromised bone situations. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

  11. Clinical Preliminary Study on Biodegradable Subcuta neous Contraceptive Implant-CaproF

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    CaproF is a biodegradable subcutaneous contraceptive implant of releasing lev onorgestrel (LNG), which is expected to provide an effective contraception for 2 years. This study was undertaken to assess the one-year preliminary clinical results of using CaproF in 19 subjects. All subjects (n = 19) completed the 1-year study, and the contraceptive effectiveness and follow up rate were both 100%. The incidence of side effects was low. The major side effects were menstrual disorder, but bleeding patterns tended to be improved and restored to be the same as pre-implantation ones with time. There were no significant increase in weight (P> 0. 05) and no changes in blood pres sure. In the 3d, 6th and 12th months after using CaproF, the cervical mucus became scanty and viscous without fern-like crystals. The amount of menstrual blood loss de creased from 49. 38 ml of pre-implantation to 33. 23 ml of the 12th month of using the implant (P<0.05). Hemoglobin concentrations showed no changes, but serum ferritin concentrations were slightly increased. No changes in liver function, kidney function, glucose tolerance test and lipoprotein levels were found. Determinations of sex hor mones (FSH, LH, E2 and progesterone) levels, ultrasonography of ovary, and en dometrial biopsy in observed group (n = 9) showed that all had normal ovulation before insertion. But ovulation was suppressed and endometrium development was inhibited after insertion. All basal body temperatures were single-phase patterns during the 1- year follow-up. This study suggested that CaproF is an effective, safe and acceptable long-acting contraceptive method. It is likely to reach its contraceptive effectiveness through suppressing ovulation, inhibiting endometrium development and influencing cervical musus characteristics.

  12. Clinical Preliminary Study on Biodegradable Subcuta-neous Contraceptive Implant-CaproF

    Institute of Scientific and Technical Information of China (English)

    刘春海; 钱丽娟

    2000-01-01

    CaproF is a biodegradable subcutaneous contraceptive implant of releasing lev-onorgestrel (LNG), which is expected to provide an effective contraception for 2 years. This study was undertaken to assess the one-year preliminary clinical results of using CaproF in 19 subjects. All subjects (n = 19) completed the 1-year study, and the contraceptive effectiveness and follow up rate were both 100%. The incidence of side effects was low. The major side effects were menstrual disorder, but bleeding patterns tended to be improved and restored to be the same as pre-implantation ones with time.There were no significant increase in weight (P> 0. 05) and no changes in blood pres-sure. In the 3rd, 6th and 12th months after using CaproF, the cervical mucus became scanty and viscous without fern-like crystals. The amount of menstrual blood loss de-creased from 49. 38 ml of pre-implantation to 33. 23 ml of the 12th month of using the implant (P< 0. 05). Hemoglobin concentrations showed no changes, but serum ferritin concentrations were slightly increased. No changes in liver function, kidney function,glucose tolerance test and lipoprotein levels zoere found. Determinations of sex hor-mones (FSH , LH , E2 and progesterone) levels, ultrasonography of ovary, and en-dometrial biopsy in observed group (n = 9) shorted that all had normal ovulation before insertion. But ovulation was suppressed and endometrium development was inhibited after insertion. All basal body temperatures were single-phase patterns during the 1-year follow-up. This study suggested that CaproF is an effective, safe and acceptable long-acting contraceptive method. It is likely to reach its contraceptive effectiveness through suppressing ovulation, inhibiting endometrium development and influencing cervical mucus characteristics.

  13. Structural study on phosphorus doping of BaSi{sub 2} epitaxial films by ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hara, K.O., E-mail: k-hara@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Gobancho, Chiyoda, Tokyo 102-0076 (Japan); Hoshi, Y. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Usami, N. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Gobancho, Chiyoda, Tokyo 102-0076 (Japan); Shiraki, Y. [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Setagaya, Tokyo 158-0082 (Japan); Nakamura, K.; Toko, K. [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8573 (Japan); Suemasu, T. [Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Gobancho, Chiyoda, Tokyo 102-0076 (Japan); Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8573 (Japan)

    2013-05-01

    Phosphorus doping of BaSi{sub 2} epitaxial films by means of P implantation and rapid thermal annealing has been investigated from a structural viewpoint. Raman spectroscopy and X-ray diffraction show that the crystal structure of BaSi{sub 2} is destroyed, at least partially, by P implantation. This irradiation damage increases with increasing the P dose from 1.0 × 10{sup 13} to 1.0 × 10{sup 15} cm{sup −2} and can be removed by rapid thermal annealing for 30 s at 600–800 °C, as evidenced by the variation of the full width at half-maximum of the A{sub 1}-mode Raman peak. In addition to the recovery of the irradiation damage, the metastable trigonal phase of BaSi{sub 2}, which is metallic and undesirable to exist in the semiconductor film, is found to form by annealing at 800 °C after P implantation of 1.0 × 10{sup 15} cm{sup −2}. Furthermore, by annealing at 600 and 700 °C, P atoms have been revealed to segregate into the surface and BaSi{sub 2}/Si interface while the P segregation is suppressed at 800 °C, according to the depth profile of P determined by secondary ion mass spectroscopy. Thus, we have obtained a useful guide of the P implantation dose and annealing temperature to effectively dope P atoms into the semiconducting BaSi{sub 2} film. - Highlights: ► P doping of BaSi{sub 2} by ion implantation and rapid thermal annealing is studied. ► The crystal structure of BaSi{sub 2} is destroyed, at least partially, by P implantation. ► The annealing condition to remove the irradiation damage is revealed. ► The trigonal BaSi{sub 2} phase forms from the highly damaged film by annealing. ► P atoms segregate at 600–800 °C.

  14. Implantation of cobalt in SnO2 thin films studied by TDPAC

    Directory of Open Access Journals (Sweden)

    Juliana Schell

    2017-05-01

    Full Text Available Here we report time differential perturbed angular correlation (TDPAC results of Co-doped SnO2 thin films. Making use of stable Co and radioactive 111In implanted at the Bonn Radioisotope Separator with energies of 80 keV and 160 keV, respectively, it was possible to study the dopant incorporation and its lattice location during annealing. The hyperfine parameters have been probed as a function of temperature in vacuum. Two quadrupole interactions were observed. At high temperatures the dominant fraction for the probe nuclei can be assigned to the Cd-incorporation at the cation substitutional site in a highly disordered structure, obtained after implantation, to high crystallinity for the measurements at 873 K and 923 K. The similarity in TDPAC spectra obtained in undoped SnO gives indirect evidence that In and Co diffuse to different depths during the annealing process. Other interpretations will be discussed.

  15. Temporary deafness can impair multisensory integration: a study of cochlear-implant users.

    Science.gov (United States)

    Landry, Simon P; Guillemot, Jean-Paul; Champoux, François

    2013-07-01

    Previous investigations suggest that temporary deafness can have a dramatic impact on audiovisual speech processing. The aim of this study was to test whether temporary deafness disturbs other multisensory processes in adults. A nonspeech task involving an audiotactile illusion was administered to a group of normally hearing individuals and a group of individuals who had been temporarily auditorily deprived. Members of this latter group had their auditory detection thresholds restored to normal levels through the use of a cochlear implant. Control conditions revealed that auditory and tactile discrimination capabilities were identical in the two groups. However, whereas normally hearing individuals integrated auditory and tactile information, so that they experienced the audiotactile illusion, individuals who had been temporarily deprived did not. Given the basic nature of the task, failure to integrate multisensory information could not be explained by the use of the cochlear implant. Thus, the results suggest that normally anticipated audiotactile interactions are disturbed following temporary deafness.

  16. A new design and computational fluid dynamics study of an implantable axial blood pump.

    Science.gov (United States)

    Koochaki, Mojtaba; Niroomand-Oscuii, Hanieh

    2013-12-01

    Considering small thoracic space, using implantable ventricular assist device requires reduction in a pump size. Among many available blood pumps, axial blood pumps have attracted greatly because of their small size. In this article, a new miniature axial blood pump has been designed and studied which can be easily implanted in the human body. In this design, the pump overall length decreased by a little increasing in the pump diameter, and new blade geometry is used to produce a streamlined, idealized, and nonobstructing blood flow path in the pump. By means of computational fluid dynamic, the flow pattern through the pump has been predicted and overall pump performance and efficiency has been computed. Also, to ensure a reliable VAD design, two methods for checking wall shear stress were used to confirm that this pump wouldn't cause serious blood damage.

  17. Theoretical study of the fibrous capsule tissue growth around a disk-shaped implant

    KAUST Repository

    Djellouli, Rabia

    2012-08-19

    We analyze the mathematical properties of the fibrous capsule tissue concentration around a disk-shaped implant. We establish stability estimates as well as monotonicity results that illustrate the sensitivity of this growth to the biocompatibility index parameters of the implant. In addition, we prove that the growth of the tissue increases exponentially in time toward an asymptotic regime. We also study the mathematical properties of the solution of the inverse problem consisting in the determination of the values of the biocompatibility index parameters from the knowledge of some fibrous capsule tissue measurements. We prove that this model calibration problem admits a unique solution, and establish a characterization of the index parameters. Furthermore, we demonstrate analytically that such a solution is not continuous with respect to the data, and therefore the considered inverse problem is ill-posed due to the lack of the stability requirement. © 2012 Springer-Verlag.

  18. Study of the amorphization of surface silicon layers implanted by low-energy helium ions

    Science.gov (United States)

    Lomov, A. A.; Myakon'kikh, A. V.; Oreshko, A. P.; Shemukhin, A. A.

    2016-03-01

    The structural changes in surface layers of Si(001) substrates subjected to plasma-immersion implantation by (2-5)-keV helium ions to a dose of D = 6 × 1015-5 × 1017 cm-2 have been studied by highresolution X-ray diffraction, Rutherford backscattering, and spectral ellipsometry. It is found that the joint application of these methods makes it possible to determine the density depth distribution ρ( z) in an implanted layer, its phase state, and elemental composition. Treatment of silicon substrates in helium plasma to doses of 6 × 1016 cm-2 leads to the formation of a 20- to 30-nm-thick amorphized surface layer with a density close to the silicon density. An increase in the helium dose causes the formation of an internal porous layer.

  19. Study of TiO{sub 2} nanotubes as an implant application

    Energy Technology Data Exchange (ETDEWEB)

    Hazan, Roshasnorlyza, E-mail: roshasnorlyza@nm.gov.my; Sreekantan, Srimala [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300, Nibong Tebal, Pulau Pinang (Malaysia); Mydin, Rabiatul Basria S. M. N.; Mat, Ishak [Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, Kepala Batas, Pulau Pinang (Malaysia); Abdullah, Yusof [Materials Technology Group, Industrial Technology Division, Nuclear Malaysia Agency, Bangi, 43000, Kajang, Selangor. Malaysia (Malaysia)

    2016-01-22

    Vertically aligned TiO{sub 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{sub 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{sub 2} nanotubes is reported. Field emission scanning electron microscopy (FESEM) analysis proved interaction of BMSC on TiO{sub 2} nanotubes structure was better than flat titanium (Ti) surface. Also, significant cell adhesion on TiO{sub 2} nanotubes surface during in vitro study revealed that BMSC prone to attach on TiO{sub 2} nanotubes. From the result, it can be conclude that TiO{sub 2} nanotubes are biocompatible to biological environment and become a new generation for advanced implant materials.

  20. A detection system for charged-particle decay studies with a continuous-implantation method

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L.J. [China Institute of Atomic Energy, Beijing 102413 (China); Xu, X.X., E-mail: xuxinxing@ciae.ac.cn [China Institute of Atomic Energy, Beijing 102413 (China); Lin, C.J., E-mail: cjlin@ciae.ac.cn [China Institute of Atomic Energy, Beijing 102413 (China); Wang, J.S. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fang, D.Q. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, Z.H. [School of Physic and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Wang, Y.T. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, J. [School of Physic and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Yang, L.; Ma, N.R. [China Institute of Atomic Energy, Beijing 102413 (China); Wang, K. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zang, H.L. [School of Physic and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Wang, H.W.; Li, C.; Shi, C.Z.; Nie, M.W.; Li, X.F.; Li, H. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Ma, J.B.; Ma, P. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); and others

    2015-12-21

    A new detection system with high detection efficiency and low detection threshold has been developed for charged-particle decay studies, including β-delayed proton, α decay or direct proton emission from proton-rich nuclei. The performance was evaluated by using the β-delayed proton emitter {sup 24}Si produced by projectile fragmentation at the First Radioactive Ion Beam Line in Lanzhou. Under a continuous-beam mode, the isotopes of interest were implanted into two double-sided silicon strip detectors, where the subsequent decays were measured and correlated to the preceding implantations by using position and time information. The system allows us to measure protons with energies down to about 200 keV without obvious β background in the proton spectrum. Further application of the detection system can be extended to the measurements of β-delayed proton decay and the direct proton emission of more exotic proton-rich nuclei.

  1. 3D Printing Surgical Implants at the clinic: A Experimental Study on Anterior Cruciate Ligament Reconstruction.

    Science.gov (United States)

    Liu, An; Xue, Guang-huai; Sun, Miao; Shao, Hui-feng; Ma, Chi-yuan; Gao, Qing; Gou, Zhong-ru; Yan, Shi-gui; Liu, Yan-ming; He, Yong

    2016-02-15

    Desktop three-dimensional (3D) printers (D3DPs) have become a popular tool for fabricating personalized consumer products, favored for low cost, easy operation, and other advantageous qualities. This study focused on the potential for using D3DPs to successfully, rapidly, and economically print customized implants at medical clinics. An experiment was conducted on a D3DP-printed anterior cruciate ligament surgical implant using a rabbit model. A well-defined, orthogonal, porous PLA screw-like scaffold was printed, then coated with hydroxyapatite (HA) to improve its osteoconductivity. As an internal fixation as well as an ideal cell delivery system, the osteogenic scaffold loaded with mesenchymal stem cells (MSCs) were evaluated through both in vitro and in vivo tests to observe bone-ligament healing via cell therapy. The MSCs suspended in Pluronic F-127 hydrogel on PLA/HA screw-like scaffold showed the highest cell proliferation and osteogenesis in vitro. In vivo assessment of rabbit anterior cruciate ligament models for 4 and 12 weeks showed that the PLA/HA screw-like scaffold loaded with MSCs suspended in Pluronic F-127 hydrogel exhibited significant bone ingrowth and bone-graft interface formation within the bone tunnel. Overall, the results of this study demonstrate that fabricating surgical implants at the clinic (fab@clinic) with D3DPs can be feasible, effective, and economical.

  2. A retrospective radiographic study on the effect of natural tooth-implant proximity and an introduction to the concept of a bone-loading platform switch.

    Science.gov (United States)

    Urdaneta, Rainer A; Seemann, Rudolf; Dragan, Irina-Florentina; Lubelski, William; Leary, Joseph; Chuang, Sung-Kiang

    2014-01-01

    The aim of this study was to evaluate the effect of tooth-implant proximity using an implant system with a double platform shift that was designed to load bone coronal to the implant-abutment cohort study was conducted between January 2008 and December 2009. The sample was composed of patients who had received at least one 5-mm-wide hydroxyapatite-coated single-tooth Bicon implant that had been placed adjacent to at least one natural tooth. Descriptive statistics and univariate and multivariate linear mixed-effects regression models, adjusted for multiple implants in the same patient, were utilized. The primary predictor variable was the horizontal distance between implant and adjacent tooth, and the primary outcome variable was the change in peri-implant bone levels over time. Two hundred six subjects who received 235 plateau root-form implants were followed for an average of 42 months. Tooth-implant distance ranged between 0 and 14.6 mm. Out of 235 implants, 43 implants were placed tooth on mesial and/or distal sides. The proximity of a plateau root-form implant was not associated with complications on the adjacent tooth such as bone loss, root resorption, endodontic treatment, pain, or extraction. The proximity of an adjacent tooth was not a risk factor for the failure of a plateau root-form implant. After adjusting for other covariates in a multivariate model, the proximity of a natural tooth did not have a statistically significant effect on peri-implant bone levels (P = .13). The extraction of an adjacent tooth was associated with a significant increase in peri-implant bone loss (P = .008). The placement of a plateau root-form implant with a sloping shoulder in close proximity to an adjacent tooth did not cause damage to that tooth or lead to bone loss or the failure of the implant.

  3. Meth (Crank, Ice) Facts

    Science.gov (United States)

    ... That People Abuse » Meth (Crank, Ice) Facts Meth (Crank, Ice) Facts Listen Methamphetamine—meth for short—is a white, bitter powder. Sometimes ... clear or white shiny rock (called a crystal). Meth powder can be eaten or snorted up the ...

  4. Assessing Basic Fact Fluency

    Science.gov (United States)

    Kling, Gina; Bay-Williams, Jennifer M.

    2014-01-01

    In this article, the authors share a variety of ways to formatively assess basic fact fluency. The define fluency, raise some issues related to timed testing, and then share a collection of classroom-tested ideas for authentic fact fluency assessment. This article encourages teachers to try a variety of alternative assessments from this sampling,…

  5. Facts for Feeding Series.

    Science.gov (United States)

    Academy for Educational Development, Washington, DC.

    This document compiles several fact sheets, in multiple languages, for mothers and parent educators providing information and answering questions concerning breastfeeding infants. The fact sheets are published in English, French, and Spanish, and cover the following topics: (1) "Recommended Practices To Improve Infant Nutrition during the…

  6. [Force-based local navigation in robot-assisted implantation bed anlage in the lateral skull base. An experimental study].

    Science.gov (United States)

    Plinkert, P K; Federspil, P A; Plinkert, B; Henrich, D

    2002-03-01

    Excellent precision, miss of retiring, reproducibility are main characteristics of robots in the operating theatre. Because of these facts their use for surgery in the lateral scull base is of great interest. In recent experiments we determined process parameters for robot assisted reaming of a cochlea implant bed and for a mastoidectomy. These results suggested that optimizing parameters for thrilling with the robot is needed. Therefore we implemented a suitable reaming curve from the geometrical data of the implant and a force controlled process control for robot assisted reaming at the lateral scull base. Experiments were performed with an industrial robot on animal and human scull base specimen. Because of online force detection and feedback of sensory data the reaming with the robot was controlled. With increasing force values above a defined limit feed rates were automatically regulated. Furthermore we were able to detect contact of the thrill to dura mater by analyzing the force values. With the new computer program the desired implant bed was exactly prepared. Our examinations showed a successful reaming of an implant bed in the lateral scull base with a robot. Because of a force controlled reaming process locale navigation is possible and enables careful thrilling with a robot.

  7. 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.

  8. 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.

  9. THE FIRST DOMESTIC IMPLANTABLE AXIAL FLOW PUMP: RESULTS OF EXPERIMENTAL STUDIES IN CALVES

    Directory of Open Access Journals (Sweden)

    G. P. Itkin

    2013-01-01

    Full Text Available Aim of our experimental study was evaluation of the first domestic implantable axial pump as a left ventricle assist device in calves. Materials and methods. 18 calves 90–120 days of age, weighing 95 ± 5 kg were exposed to implantation of an axial pump under the scheme «left ventricular – aorta» in paracorporeal and implantable in chest cavity versions. Two models of the pump were tested. Model 1 is a pump with cylindrical bearings and elongated straightener, model 2 had ball bearings and modified design of impeller and straightener. Results. In the first series (n = 12 the pump model 1 was tested. The duration of experiments was 4,9 ± 5,3 days, maximal duration was 16 days. The experiments were finalized due to intraoperation cardiac fibrillation (n = 3, uncrop- ped acute bleeding (n = 3, lowering of blood flow through the pump of 60 ± 15% (n = 6 because of thrombo- sis of the pump (n = 5 and outlet line (n = 1, in 3 cases of 5, combined with mechanical wear of bearings. In the second series (n = 6 the pump model 2 was tested. In 4 experiments of 6 the duration was 74,5 ± 29 days. One experiment was finalized due to intraoperation cardiac fibrillation. Another one experiment was finalized on 8 day as planned. In 5 experiments there was absence of either thrombosis or mechanical wear of bearings. Morphological and histological examination of the kidneys, liver and lungs in the 5 experiments of second series did not reveal the presence of zones of ischemia or thromboembolia. Conclusion. The results of the second series can be treaded as preclinical testing of the first domestic implantable axial pump as a left ventricle assist device in calves. 

  10. Studies on indomethacin intraocular implants using different in vitro release methods

    Directory of Open Access Journals (Sweden)

    Balasubramaniam J

    2008-01-01

    Full Text Available Intra ocular implants of sodium alginate alone and in combination with hydroxypropylmethylcellulose with or without calcium chloride were formulated with indomethacin as a model drug. The drug release from the implants was evaluated using static method, continuous flow through apparatus (developed in house, USP dissolution and agar diffusion. Except in the static method, indomethacin particle size did not impart any effect on the drug release. In agar diffusion method, an increase in agar concentration from 1 to 2% resulted in a significant decrease (P< 0.005 in the amount of drug released. Inclusion of hydroxypropylmethylcellulose (33.3, 41.6 and 50% w/w, resulted in decrease of indomethacin release irrespective of the method of dissolution study. The agar diffusion method and the continuous flow through methods seem to simulate to a certain extent the in vivo conditions as far as the placement of the device and the hydrodynamic diffusion layer around the intra ocular implant is concerned. The static method and USP method affected the hydrodynamic diffusion layer either too slowly or too fast.

  11. Peri-implant tissue behavior around non-titanium material: Experimental study in dogs.

    Science.gov (United States)

    Maté Sánchez de Val, José Eduardo; Gómez-Moreno, Gerardo; Pérez-Albacete Martínez, Carlos; Ramírez-Fernández, Maria Piedad; Granero-Marín, Jose Manuel; Gehrke, Sergio Alexandre; Calvo-Guirado, José Luis

    2016-07-01

    The aim of this study is to assess the effectiveness of using non-titanium abutments for better establishment of peri-implant biological width and to assess the stability of the soft tissue. Forty-eight tapered dental titanium implants with internal connection of 3.5mm in diameter and 10mm length were implanted in post extraction alveoli of 6 dogs. Twenty-four abutments made in a reinforced polyetheretherketone (PEEK) formed the test group, and 24 titanium abutments, the control group. The groups were randomized. Histological, histomorphometric, ISQ and radiological analyses were performed. Greatest differences (control group vs. test group) were found at PM-Lc (Mucosa to lingual bone contact) (2.91±0.03 vs. 3.71±0.18), and to PM Lingual-IS (2.65±0.43 vs. 3.57±0.38). Reinforced PEEK constitutes an effective alternative to conventional titanium abutments, given its high rate of biocompatibility, preservation of bone height and soft tissue stability.

  12. How to test mode switching in pacemakers implanted in patients: the MOST study.

    Science.gov (United States)

    Padeletti, Luigi; Gasparini, Maurizio; Porciani, Maria Cristina; Pieragnoli, Paolo; Colella, Andrea; Michelucci, Antonio; Proclemer, Alessandro; Tognarini, Stefano; Mantica, Massimo; Coltorti, Fernando; Corbucci, Giorgio; Sutton, Richard

    2002-02-01

    Optimal management of atrial arrhythmias with dual chamber pacemakers requires proper performance of automatic mode switching (AMS). The aim of this study was to develop a reliable technique to test the AMS function by using an external electronic device capable of mimicking the occurrence of supraventricular arrhythmias (Supraventricular Arrhythmia Simulator [SAS]). The SAS delivers low voltage pulse trains (200 mV, 20 ms) through two skin electrodes. Each pulse train lasts 15 seconds and starts synchronously with a pacing pulse of the implanted pacemaker to avoid interference from the operator. The pulse train rate is set at 350, 250, and 160 beats/min to simulate AF, atrial flutter, and atrial tachycardia (AT), respectively. Thirty-five patients implanted with Vitatron pacemakers, whose AMS system has been previously validated, were enrolled. Atrial and ventricular sensing were programmed in unipolar mode at 0.5 mV and in bipolar mode at > 2 mV, respectively. All pulses from the SAS were detected by the atrial channel at an amplitude ranging from 1 to 3 mV. The test proved to be safe and reliable at rest and during exercise. AMS occurred immediately at onset or at offset of atrial arrhythmias, and no adverse interference on pacemaker function was seen from the SAS. In conclusion, the described technique and the SAS are safe and reliable for patient and pacemaker function and can be proposed as a useful method to verify proper performance of AMS function irrespective of the type of implanted devices.

  13. Microstructure of Fe implanted yttria stabilised zirconia studied by Moessbauer spectroscopy and TEM

    Energy Technology Data Exchange (ETDEWEB)

    Burggraaf, A.J.; Scholten, D.; Hassel, B.A. van

    1988-05-01

    Single crystalline and ceramic solid solutions of (1-0.chi)(ZrO/sub 2/)-(0.chi)(YO/sub 1.5/) with chi = 14-17 were implanted with high doses of Fe. Specific profile shapes were realised. The microstructure of the material before and after annealing was studied by conversion electron Moessbauer spectroscopy (CEMS), ion channeling and transmission electron microscopy (TEM). Initially Fe is present as metallic particles Fe/sup 0/ and as Fe/sup 2+/ and Fe/sup 3+/ ions. Their relative abundancy depends on the implantation conditions. Annealing leads to complete oxidation (Fe/sup 3+/) at low temperature and to the formation of microprecipitates of Fe/sub 2/O/sub 3/ (< 5 nm). A maximum of 4.5x10/sup 21/ Fe cm/sup -3/ can be substitutionally incorporated for Zr. This Fe is present in a metastable state. Ion channeling and electron diffraction experiments revealed that high fluence Fe implantation does not result in amorphisation but in recrystallisation of the matrix.

  14. Study of the effects of focused high-energy boron ion implantation in diamond

    Science.gov (United States)

    Ynsa, M. D.; Agulló-Rueda, F.; Gordillo, N.; Maira, A.; Moreno-Cerrada, D.; Ramos, M. A.

    2017-08-01

    Boron-doped diamond is a material with a great technological and industrial interest because of its exceptional chemical, physical and structural properties. At modest boron concentrations, insulating diamond becomes a p-type semiconductor and at higher concentrations a superconducting metal at low temperature. The most conventional preparation method used so far, has been the homogeneous incorporation of boron doping during the diamond synthesis carried out either with high-pressure sintering of crystals or by chemical vapour deposition (CVD) of films. With these methods, high boron concentration can be included without distorting significantly the diamond crystalline lattice. However, it is complicated to manufacture boron-doped microstructures. A promising alternative to produce such microstructures could be the implantation of focused high-energy boron ions, although boron fluences are limited by the damage produced in diamond. In this work, the effect of focused high-energy boron ion implantation in single crystals of diamond is studied under different irradiation fluences and conditions. Micro-Raman spectra of the sample were measured before and after annealing at 1000 °C as a function of irradiation fluence, for both superficial and buried boron implantation, to assess the changes in the diamond lattice by the creation of vacancies and defects and their degree of recovery after annealing.

  15. Continuous corticosterone delivery via the drinking water or pellet implantation: A comparative study in mice.

    Science.gov (United States)

    Gasparini, Sylvia J; Weber, Marie-Christin; Henneicke, Holger; Kim, Sarah; Zhou, Hong; Seibel, Markus J

    2016-12-01

    In order to investigate the effects of glucocorticoid excess in rodent models, reliable methods of continuous glucocorticoid delivery are essential. The current study compares two methods of corticosterone (CS) delivery in regards to their ability to induce typical adverse outcomes such as fat accrual, insulin resistance, sarcopenia and bone loss. Eight-week-old mice received CS for 4weeks either via the drinking water (25-100μgCS/mL) or through weekly surgical implantation of slow release pellets containing 1.5mg CS. Both methods induced abnormal fat mass accrual, inhibited lean mass accretion and bone expansion, suppressed serum osteocalcin levels and induced severe insulin resistance. There was a clear dose dependant relationship between the CS concentrations in the drinking water and the severity of the phenotype, with a concentration of 50μg CS/mL drinking water most closely matching the metabolic changes induced by weekly pellet implantations. In contrast to pellets, however, delivery of CS via the drinking water resulted in a consistent diurnal exposure pattern, closely mimicking the kinetics of clinical glucocorticoid therapy. In addition, the method is safe, inexpensive, easily adjustable, non-invasive and avoids operative stress to the animals. Our data demonstrate that delivery of CS via the drinking water has advantages over weekly implantations of slow-release pellets. A dose of 50μg CS/mL drinking water is appropriate for the investigation of chronic glucocorticoid excess in mice.

  16. Study of shallow and deep damage in Cu and Al after self-implantation

    Energy Technology Data Exchange (ETDEWEB)

    Lindgreen, R.J.Th.; Boerma, D.O.; de Hosson, J.Th.M. (Rijks-universiteit Groningen (Netherlands). Materials Science Centre)

    1983-05-01

    The damage formed by self-implantation in Cu and Al at two temperatures, where vacancies are considered to be either immobile or mobile, but where interstitials are always highly mobile, is studied before and after annealing, using dechanneling methods. Two different regions of damage are distinguished: a surface region coinciding with the projected range of the implanted self-ions, and a region extending up to 10 times beyond this range. On the basis of differences on the formation of the deep and the shallow damage as a function of implantation temperature and a different behaviour of annealing it is concluded that the two regions contain different types of damage. A mechanism is proposed that explains the observed damage distributions qualitatively. In this model the damage in the surface region of copper is assumed to consist of mainly clusters of vacancies. In the deep region of copper and aluminium it is assumed that the damage consists of clusters or loops formed by interstitials.

  17. Study of the feasible size of a bone conduction implant transducer in the temporal bone.

    Science.gov (United States)

    Reinfeldt, Sabine; Östli, Per; Håkansson, Bo; Taghavi, Hamidreza; Eeg-Olofsson, Måns; Stalfors, Joacim

    2015-04-01

    The aim was to assess the temporal bone volume to determine the suitable size and position of a bone conduction implant (BCI) transducer. A BCI transducer needs to be sufficiently small to fit in the mastoid portion of the temporal bone for a majority of patients. The anatomical geometry limits both the dimension of an implanted transducer and its positions in the temporal bone to provide a safe and simple surgery. Computed tomography (CT) scans of temporal bones from 22 subjects were virtually reconstructed. With an algorithm in MATLAB, the maximum transducer diameter as function of the maximum transducer depth in the temporal bone, and the most suitable position were calculated in all subjects. An implanted transducer diameter of 16 mm inserted at a depth of 4 mm statistically fitted 95% of the subjects. If changing the transducer diameter to 12 mm, a depth of 6 mm would fit in 95% of the subjects. The most suitable position was found to be around 20 mm behind the ear canal. The present BCI transducer casing, used in ongoing clinical trials, was designed from the results in this study, demonstrating that the present BCI transducer casing (largest diameter [diagonal]: 15.5 mm, height: 6.4 mm) will statistically fit more than 95% of the subjects. Hence, the present BCI transducer is concluded to be sufficiently small to fit most normal-sized temporal bones and should be placed approximately 20 mm behind the ear canal.

  18. Cd doping of AlN via ion implantation studied with perturbed angular correlation

    CERN Document Server

    Kessler, Patrick; Miranda, Sérgio MC; Simon, R; Correia, João Guilherme; Johnston, Karl; Vianden, Reiner

    2012-01-01

    AlN with a wide bandgap of 6.2 eV is a promising candidate for ultraviolet light-emitting diodes and laser diodes. However, the production of the required p-type AlN is still challenging. As a possible dopant Cd was suggested among other Group II atoms (Be, Mg, and Zn). In this study the annealing condition of implanted Cd in AlN was investigated with the method of the perturbed angular correlation (PAC). Therefore radioactive $^{117}$Cd or $^{111m}$Cd ions were implanted into thin AlN films on sapphire substrate with an energy of 30 keV and fluences in the range of 10$^{11}$ ions/cm$^{2}$. After thorough annealing with a proximity cap of the same material most of the Cd-probes occupy substitutional lattice sites and almost all implantation damage can be annealed. This results in a distinct frequency in the PAC spectra which increases with temperature. In contrast to the formation of an indium nitrogen-vacancy complex observed with the probe $^{111}$In on substitutional Al-sites no defects are bound to substi...

  19. Auditory and oral language abilities in children with cochlear implants: a case study.

    Science.gov (United States)

    Melo, Tatiana Mendes de; Lara, Jessica Domingues

    2012-01-01

    The cochlear implant (CI) represents the most important advance in the treatment of individuals with severe to profound bilateral hearing loss who do not benefit from hearing aids. Children who receive the CI during the critical period of neuroplasticity of the auditory system, when combined with speech therapy, have the chance to develop the auditory and linguistic skills similarly to their normal hearing peers. Two cases of implanted children are presented in this study, and one of them was not enrolled in a formal aurioral therapeutic program since the implantation surgery. At the moment of language and auditory assessment, the children were 2 years and 5 months old, and the CI had been used for 11 months. According to the results presented, it was observed that the child enrolled in rehabilitation program had better auditory and language performance when compared to the other child. Despite the remarkable benefits that the CI provides to children with hearing impairment, the device itself only provides the child with the audibility of environmental sounds and speech signal. For the auditory and language development to happen, it is necessary, among other factors, a speech-language intervention, with partnership between professionals and parents.

  20. Music therapy as specific and complementary training for adults after cochlear implantation: A pilot study.

    Science.gov (United States)

    Hutter, E; Argstatter, H; Grapp, M; Plinkert, P K

    2015-09-01

    Although cochlear implant (CI) users achieve good speech comprehension, they experience difficulty perceiving music and prosody in speech. As the provision of music training in rehabilitation is limited, a novel concept of music therapy for rehabilitation of adult CI users was developed and evaluated in this pilot study. Twelve unilaterally implanted, postlingually deafened CI users attended ten sessions of individualized and standardized training. The training started about 6 weeks after the initial activation of the speech processor. Before and after therapy, psychological and musical tests were applied in order to evaluate the effects of music therapy. CI users completed the musical tests in two conditions: bilateral (CI + contralateral, unimplanted ear) and unilateral (CI only). After therapy, improvements were observed in the subjective sound quality (Hearing Implant Sound Quality Index) and the global score on the self-concept questionnaire (Multidimensional Self-Concept Scales) as well as in the musical subtests for melody recognition and for timbre identification in the unilateral condition. Discussion Preliminary results suggest improvements in subjective hearing and music perception, with an additional increase in global self-concept and enhanced daily listening capacities. The novel concept of individualized music therapy seems to provide an effective treatment option in the rehabilitation of adult CI users. Further investigations are necessary to evaluate effects in the area of prosody perception and to separate therapy effects from general learning effects in CI rehabilitation.

  1. Evaluation of guided bone generation around implants placed into fresh extraction sockets: an experimental study in dogs

    DEFF Research Database (Denmark)

    Gotfredsen, K; Nimb, L; Buser, D

    1993-01-01

    . The objective of this study was to evaluate the crestal bone healing response adjacent to implants placed immediately into fresh extraction sockets with and without covering membranes. Eight adult mongrel dogs had the third and fourth mandibular premolars extracted bilaterally. Thirty-two submerged titanium...... an implant is placed immediately into an extraction socket, it may not engage the walls of the socket near the crest of the alveolar ridge. With the presence of a bone defect around an implant, ingrowth of soft tissue could compromise the achievement of osseointegration in the crestal bone area...

  2. Estudio piloto comparativo entre cubetas individuales en implantoprótesis Comparative pilot study between custom trays in implant prosthetic

    OpenAIRE

    A. Orozco Varo; R. Martínez de Fuentes; P Domínguez Cardoso; D. Cañadas Rodríguez; E Jiménez Castellanos

    2006-01-01

    El presente trabajo tiene por objeto realizar un estudio piloto sobre las características más idóneas de las cubetas de impresión para prótesis sobre implantes, adjuntando una revisión de la literatura y proponiendo un material y diseño específico para cubetas individuales en prótesis sobre implantes.The present work have to object to make a pilot study about the ideal characteristcs of impression trays for implant prosthodontic, attaching a literature review and suggesting a specific materia...

  3. Frequency of Dental Implants Placed in the Esthetic Zone in Dental Clinic of Tehran University: A Descriptive Study

    Directory of Open Access Journals (Sweden)

    Amir Alireza Rasouli Ghahroudi

    2016-08-01

    Full Text Available Objectives: Anterior maxilla, known as the esthetic zone, plays an important role in facial and smile esthetics. This study assessed the frequency of implant treatments in the esthetic zone of patients presenting to Dental Implant Department of Tehran University during 2002-2012.Materials and Methods: This descriptive study was conducted on dental records of patients receiving implant treatment during 2002-2012. Patient records were retrieved from the archives and patient demographics, implant characteristics, failure rate, prevalence of complications and implant systems were collected. The data were reported as frequency and percentage.Results: Of a total of 2,381 implants placed in the mentioned time period, 492 (20.8% had been placed in the anterior maxilla and 531 (22.3% had been placed in the anterior mandible from canine to canine.  Timing of implant placement was immediate in 12.0%, early in 0.5% and late in 87.4%. Survival rate was 99.1%. Rate of failure was 0.8%. Failure rate was 0.4% in the maxillary and 1.1% in the mandibular canine to canine region. Complications were reported in 10.1% of patients. Rate of complications was 18.3% in the maxillary canine to canine, 8.9% in the mandibular canine to canine, 18.1% in the maxillary first premolar to first premolar and 9.5% in the mandibular first premolar to first premolar. The frequency of bone grafts placed in these areas was 17.6%, 33.9%, 13.6%, 32.1% and 14.3%, respectively.Conclusion: Of implants placed in our center, around 20% were in the anterior maxilla, and delayed implant placement was the most commonly adopted technique.

  4. 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.

  5. Bone Morphometric Evaluation around Immediately Placed Implants Covered with Porcine-Derived Pericardium Membrane: An Experimental Study in Dogs

    Directory of Open Access Journals (Sweden)

    Ryo Jimbo

    2012-01-01

    Full Text Available Objective. To investigate whether porcine-derived bioresorbable pericardium membrane coverage enhances the osseointegration around implants placed in fresh extraction sockets. Study Design. Twenty-four commercially available endosseous implants were placed in the fresh extraction sockets of the mandibular first molar of mature beagles (. On one side, implants and osteotomy sites were covered with porcine-derived bioresorbable pericardium membranes, whereas on the other side, no membranes were used. After 6 weeks, samples were retrieved and were histologically processed for histomorphometric analysis. Results. The histological observation showed that bone loss and soft tissue migration in the coronal region of the implant were evident for the control group, whereas bone fill was evident up to the neck of the implant for the membrane-covered group. Bone-to-implant contact was significantly higher for the membrane-covered group compared to the control group, 75% and 45% (, respectively. Conclusion. The experimental membranes proved to regenerate bone around implants placed in fresh extraction sockets without soft tissue intrusion.

  6. Study of surface exfoliation on 6H-SiC induced by H{sub 2}{sup +} implantation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L. [Department of Physics, School of Science, Lanzhou University of Technology, Lanzhou 730050 (China); Li, B.S., E-mail: b.s.li@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2017-03-01

    The effect of lattice damage generated by the H{sub 2}{sup +}-implantation on exfoliation efficiency in 6H-SiC wafers is investigated. <0001> 6H-SiC wafers were implanted with 134 keV H{sub 2}{sup +} ions to ion fluences from 1.5×10{sup 16} to 5×10{sup 16} H{sub 2}{sup +} cm{sup −2} and subsequently annealed at temperatures from 973 K to 1373 K. The samples were studied by a combination of optical microscopy and transmission electron microscopy. Only after 1373 K annealing for 15 min, blisters and exfoliation occur on the H{sub 2}{sup +}-implanted sample surface. With increasing the implantation fluences from 1.5×10{sup 16} to 3.75×10{sup 16} H{sub 2}{sup +} cm{sup −2}, the exfoliation mean size decreases, while the exfoliation density increases. For the highest fluence of 5×10{sup 16} H{sub 2}{sup +} cm{sup −2}, seldom exfoliations occur on the sample surface. Microstructure analysis shows that exfoliation efficiency is largely controlled by the H{sub 2}{sup +}-implantation-induced lattice damage. The depth of the microcrack is related to the implantation fluence. The effect of implantation fluence on dislocation loops, platelet nucleation and growth is investigated.

  7. A prospective 5-year study of fixed partial prostheses supported by implants with machined and TiO2-blasted surface

    DEFF Research Database (Denmark)

    Gotfredsen, K; Karlsson, U

    2001-01-01

    PURPOSE: The aim of the present study was to evaluate whether there was a difference between machined and TiO(2)-blasted implants regarding survival rate and marginal bone loss during a 5-year observation period. MATERIALS AND METHODS: A total of 133 implants (Astra Tech Dental Implants; Astra Tech...... and 1 TiO(2)-blasted implant. The implant-supported fixed partial prostheses (ISFPP) were fabricated within 2 months after postoperative healing. A total of 52 ISFPP (17 maxillary, 35 mandibular) were inserted. The patients were clinically examined once a year for 5 years. At the annual follow......-up, biological as well as technical complications were recorded. RESULTS: Of the 133 implants placed, 3 were reported as failed after 5 years of follow-up, resulting in an overall cumulative survival rate of 97.6%. The cumulative implant survival rates were 100% for the TiO(2)-blasted implants and 95...

  8. Assessment of Myeloperoxidase and Nitric Levels around Dental Implants and Natural Teeth as a Marker of Inflammation: A Comparative Study.

    Science.gov (United States)

    Kulkarni, Gayithri H; Jadhav, Prashant; Kulkarni, Kiran; Shinde, Sachin V; Patil, Yojana B; Kumar, Manish

    2016-11-01

    Dental implants form the mainstay of dental treatment involving rehabilitation of missing teeth. One of the major concerns for the clinicians doing dental implants is the postsurgical failure of dental implants. Success of dental implants is dependent upon the skills of the surgeon and the amount and quality of the bone remaining at the edentulous area where dental implant has to be placed. Myeloperoxidase (MPO) and nitrites are few of the enzymes and molecules which are said to be altered in inflammation. However, their exact role in the inflammatory processes around natural tooth and dental implant is still unclear. Hence we comparatively evaluated the levels of MPO and nitrites in the areas around the dental implants and natural teeth. The present study comprises 42 patients who underwent prosthetic rehabilitation by dental implants from 2011 to 2014. Depth of probing value (DP), score of plaque index (SPI), gingival index (GI), and index of gingival bleeding time (GBT) were evaluated for the assessment of the periimplant soft tissue changes. Assessment of inflammation around the dental implant surface and around natural tooth was done based on the readings of these parameters. For the measurement of the MPO levels, spectrophotometric MPO assay was used. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. The mean plaque index values were 1.56 and 0.97 in periodontitis cases of natural teeth and inflamed cases of dental implants respectively. While comparing mean plaque index, mean probing depth, and mean gingival bleeding index in between the two groups, significant difference was obtained. Mean MPO concentration in periodontitis and gingivitis cases in natural teeth were 0.683 and 0.875 U/μL, while in inflamed dental implant cases, the mean value was 0.622 U/μL. While comparing the total MPO levels, total nitrite levels, and total nitrite concentration in between two study groups, significant difference was obtained

  9. 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.

  10. 3D Printing/Additive Manufacturing Single Titanium Dental Implants: A Prospective Multicenter