WorldWideScience

Sample records for replacement materials implants

  1. Stress shielding in periprosthetic bone following a total knee replacement: Effects of implant material, design and alignment.

    Science.gov (United States)

    Zhang, Qing-Hang; Cossey, Andrew; Tong, Jie

    2016-12-01

    Periprosthetic bone strain distributions in some of the typical cases of total knee replacement (TKR) were studied with regard to the selection of material, design and the alignments of tibial components to examine which conditions are more forgiving than the others to stress shielding post a TKR. Four tibial components with two implant designs (cruciate sacrificing and cruciate retaining) and material properties (metal-backed (MB) and all-polyethylene (AP)) were considered in a specimen-specific finite element tibia bone model loaded in a neutral position. The influence of tibial material and design on the periprosthetic bone strain response was investigated under the peak loads of walking and stair descending/ascending. Two of the models were also modified to examine the effect of selected implant malalignment conditions (7° posterior, 5° valgus and 5° varus) on stress shielding in the bone, where the medio-lateral load share ratios were adjusted accordingly. The predicted increases of bone density due to implantation for the selected cases studied were also presented. For the cases examined, the effect of stress shielding on the periprosthetic bone seems to be more significantly influenced by the implant material than by the implant geometry. Significant stress shielding is found in MB cases, as opposed to increase in bone density found in AP cases, particularly in the bones immediately beneath the baseplate. The effect of stress shielding is reduced somewhat for the MB components in the malaligned positions compared with the neutral case. In AP cases, the effect of stress shielding is mostly low except in the varus position, possibly due to off-loading of lateral condyle. Increases in bone density are found in both MB and AP cases for the malaligned conditions. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  2. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    Directory of Open Access Journals (Sweden)

    Bloemer Wilhelm

    2010-01-01

    Full Text Available Abstract Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68 of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years and the average weight 102.3 kg (75 to 130 kg. The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck

  3. Degradation of implant materials

    CERN Document Server

    Eliaz, Noam

    2012-01-01

    This book surveys the degradation of implant materials, reviewing in detail such failure mechanisms as corrosion, fatigue and wear, along with monitoring techniques. Surveys common implant biomaterials, as well as procedures for implant retrieval and analysis.

  4. Synthetic Versus Tissue-Engineered Implants for Joint Replacement

    Directory of Open Access Journals (Sweden)

    Duncan E. T. Shepherd

    2007-01-01

    Full Text Available Human synovial joints are remarkable as they can last for a lifetime. However, they can be affected by disease that may lead to destruction of the joint surface. The most common treatment in the advanced stages of joint disease is artificial joint replacement, where the diseased synovial joint is replaced with an artificial implant made from synthetic materials, such as metals and polymers. A new technique for repairing diseased synovial joints is tissue engineering where cells are used to grow replacement tissue. This paper explores the relative merits of synthetic and tissue-engineered implants, using joint replacement as an example. Synthetic joint replacement is a well-established procedure with the advantages of early mobilisation, pain relief and high patient satisfaction. However, synthetic implants are not natural tissues; they can cause adverse reactions to the body and there could be a mismatch in mechanical properties compared to natural tissues. Tissue-engineered implants offer great potential and have major advantages over synthetic implants as they are natural tissue, which should ensure that they are totally biocompatible, have the correct mechanical properties and integrate well with the existing tissue. However, there are still many limitations to be addressed in tissue engineering such as scaling up for production, bioreactor design, appropriate regulation and the potential for disease to attack the new tissue-engineered implant.

  5. Bonding over Dentin Replacement Materials.

    Science.gov (United States)

    Meraji, Naghmeh; Camilleri, Josette

    2017-08-01

    Dentin replacement materials are necessary in large cavities to protect the pulp and reduce the bulk of filling material. These materials are layered with a composite resin restorative material. Microleakage caused by poor bonding of composite resin to underlying dentin replacement material will result in pulp damage. The aim of this study was to characterize the interface between dentin replacement materials and composite resin and to measure the shear bond strength after dynamic aging. Biodentine (Septodont, Saint Maur-des-Fosses, France), Theracal LC (Bisco, Schaumburg, IL), and Fuji IX (GC, Tokyo, Japan) were used as dentin replacement materials. They were then overlaid with a total-etch and bonding agent or a self-etch primer and composite resin or a glass ionomer cement. All combinations were thermocycled for 3000 cycles. The interface was characterized using scanning electron microscopy and elemental mapping. Furthermore, the shear bond strength was assessed. The Biodentine surface was modified by etching. The Theracal LC and Fuji IX microstructure was unchanged upon the application of acid etch. The Biodentine and glass ionomer interface showed an evident wide open space, and glass particles from the glass ionomer adhered to the Biodentine surface. Elemental migration was shown with aluminum, barium, fluorine, and ytterbium present in Biodentine from the overlying composite resin. Calcium was more stable. The bond strength between Theracal LC and composite using a total-etch technique followed by self-etch primer achieved the best bond strength values. Biodentine exhibited the weakest bond with complete failure of bonding shown after demolding and thermocycling. Dynamic aging is necessary to have clinically valid data. Bonding composite resin to water-based dentin replacement materials is still challenging, and further alternatives for restoration of teeth using such materials need to be developed. Copyright © 2017 American Association of Endodontists

  6. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas;

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacement....... We report the first case of surgical valve replacement in a patient with a dysfunctional transcatheter-implanted aortic valve prosthesis 4 months after implantation....

  7. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

    Directory of Open Access Journals (Sweden)

    Banerjee Nandini

    2013-08-01

    Full Text Available A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness and predictability of endosseous implants. Implant placement is a viable option in the treatment of partial and full edentulism and has become an integral facet of periodontal therapy. The available implants are remarkably successful. This review discusses the different aspects of dental implant including its advantages over the contemporary removable implants, its procedure in detail and the financial outlook of the same. The review also has a small consideration on minidental implant.

  8. Carbon offers advantages as implant material in human body

    Science.gov (United States)

    Benson, J.

    1969-01-01

    Because of such characteristics as high strength and long-term biocompatability, aerospace carbonaceous materials may be used as surgical implants to correct pathological conditions in the body resulting from disease or injury. Examples of possible medical uses include bone replacement, implantation splints and circulatory bypass implants.

  9. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

    OpenAIRE

    Banerjee Nandini; Singh Sushma

    2013-01-01

    A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness a...

  10. A Retrospective Analysis of Dental Implants Replacing Failed Implants in Grafted Maxillary Sinus: A Case Series.

    Science.gov (United States)

    Manor, Yifat; Chaushu, Gavriel; Lorean, Adi; Mijiritzky, Eithan

    2015-01-01

    To evaluate the survival rate of dental implants replacing failed implants in grafted maxillary sinuses using the lateral approach vs nongrafted posterior maxillae. A retrospective analysis was conducted to study the survival of secondary dental implants inserted in the posterior maxilla in previously failed implant sites between the years 2000 and 2010. The study group consisted of patients who had also undergone maxillary sinus augmentation, and the control group consisted of patients in whom implants in the posterior maxilla had failed. Clinical and demographic data were analyzed using a structured form. Seventy-five patients with a total of 75 replaced implants were included in the study. The study group comprised 40 patients and the control group, 35 patients. None of the replaced implants in the study group failed, resulting in an overall survival of 100%; three replaced implants in the control group failed (92% survival). The main reason for the primary implant removal was lack of osseointegration (35 [87.5%] of 40 study group implants and 23 [65.7%] of 35 control group implants [P = .027]). The difference between the groups with regard to the timing of primary implant failure was statistically significant. The study group had more early failures of the primary implant than did the control group (77% vs 62%; P = .038). Dental implants replaced in the posterior maxilla had a high survival rate. A higher rate of survival was found in augmented maxillary sinus sites. Within the limits of the present study, it can be concluded that previous implant failures in the grafted maxillary sinus should not discourage practitioners from a second attempt.

  11. Implant materials modified by colloids

    Directory of Open Access Journals (Sweden)

    Zboromirska-Wnukiewicz Beata

    2016-03-01

    Full Text Available Recent advances in general medicine led to the development of biomaterials. Implant material should be characterized by a high biocompatibility to the tissue and appropriate functionality, i.e. to have high mechanical and electrical strength and be stable in an electrolyte environment – these are the most important properties of bioceramic materials. Considerations of biomaterials design embrace also electrical properties occurring on the implant-body fluid interface and consequently the electrokinetic potential, which can be altered by modifying the surface of the implant. In this work, the surface of the implants was modified to decrease the risk of infection by using metal colloids. Nanocolloids were obtained using different chemical and electrical methods. It was found that the colloids obtained by physical and electrical methods are more stable than colloids obtained by chemical route. In this work the surface of modified corundum implants was investigated. The implant modified by nanosilver, obtained by electrical method was selected. The in vivo research on animals was carried out. Clinical observations showed that the implants with modified surface could be applied to wounds caused by atherosclerotic skeleton, for curing the chronic and bacterial inflammations as well as for skeletal reconstruction surgery.

  12. Fiber glass-bioactive glass composite for bone replacing and bone anchoring implants.

    Science.gov (United States)

    Vallittu, Pekka K; Närhi, Timo O; Hupa, Leena

    2015-04-01

    Although metal implants have successfully been used for decades, devices made out of metals do not meet all clinical requirements, for example, metal objects may interfere with some new medical imaging systems, while their stiffness also differs from natural bone and may cause stress-shielding and over-loading of bone. Peer-review articles and other scientific literature were reviewed for providing up-dated information how fiber-reinforced composites and bioactive glass can be utilized in implantology. There has been a lot of development in the field of composite material research, which has focused to a large extent on biodegradable composites. However, it has become evident that biostable composites may also have several clinical benefits. Fiber reinforced composites containing bioactive glasses are relatively new types of biomaterials in the field of implantology. Biostable glass fibers are responsible for the load-bearing capacity of the implant, while the dissolution of the bioactive glass particles supports bone bonding and provides antimicrobial properties for the implant. These kinds of combination materials have been used clinically in cranioplasty implants and they have been investigated also as oral and orthopedic implants. The present knowledge suggests that by combining glass fiber-reinforced composite with particles of bioactive glass can be used in cranial implants and that the combination of materials may have potential use also as other types of bone replacing and repairing implants. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Minimally Invasive Mitral Valve Replacement and Transfemoral Aortic Valve Implantation.

    Science.gov (United States)

    Rustenbach, Christian; Baumbach, Hardy; Hill, Stephan; Franke, Ulrich F W

    2015-01-01

    The case is reported of a symptomatic elderly patient with severe mitral regurgitation, severe aortic valve stenosis, and coronary heart disease. The coronary artery disease had been interventionally treated four years previously with stent implantation into the right coronary artery. Published studies have shown that a combination of mitral and aortic valve surgery is associated with a significantly increased risk of mortality and morbidity, particularly in elderly patients. In the present patient, both valvular malformations were successfully treated with a single-step interdisciplinary approach, namely an initial surgical mitral valve replacement followed by transfemoral transcatheter aortic valve replacement.

  14. Magnesium as Biodegradable Implant Material

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Drawbacks associated with permanent metallic implants lead to the search for degradable metallic biomaterials. Magnesium alloys have been highly considered as Mg has a high biocorrosion potential and is essential to bodies. In this study, corrosion behaviour of pure magnesium and magnesium alloy AZ31 in both static and dynamic physiological conditions (Hank's solution) has been investigated. It is found that the materials degrade fast at beginning, then stabilize after 5 days of immersion. High purity in th...

  15. [Carbon fiber-reinforced plastics as implant materials].

    Science.gov (United States)

    Bader, R; Steinhauser, E; Rechl, H; Siebels, W; Mittelmeier, W; Gradinger, R

    2003-01-01

    Carbon fiber-reinforced plastics have been used clinically as an implant material for different applications for over 20 years.A review of technical basics of the composite materials (carbon fibers and matrix systems), fields of application,advantages (e.g., postoperative visualization without distortion in computed and magnetic resonance tomography), and disadvantages with use as an implant material is given. The question of the biocompatibility of carbon fiber-reinforced plastics is discussed on the basis of experimental and clinical studies. Selected implant systems made of carbon composite materials for treatments in orthopedic surgery such as joint replacement, tumor surgery, and spinal operations are presented and assessed. Present applications for carbon fiber reinforced plastics are seen in the field of spinal surgery, both as cages for interbody fusion and vertebral body replacement.

  16. Neutrophil Responses to Sterile Implant Materials

    OpenAIRE

    Siddharth Jhunjhunwala; Stephanie Aresta-DaSilva; Katherine Tang; David Alvarez; Webber, Matthew J.; Tang, Benjamin C.; Lavin, Danya M.; Omid Veiseh; Doloff, Joshua C; Suman Bose; Arturo Vegas; Minglin Ma; Gaurav Sahay; Alan Chiu; Andrew Bader

    2015-01-01

    In vivo implantation of sterile materials and devices results in a foreign body immune response leading to fibrosis of implanted material. Neutrophils, one of the first immune cells to be recruited to implantation sites, have been suggested to contribute to the establishment of the inflammatory microenvironment that initiates the fibrotic response. However, the precise numbers and roles of neutrophils in response to implanted devices remains unclear. Using a mouse model of peritoneal microcap...

  17. Bone remodeling induced by dental implants of functionally graded materials.

    Science.gov (United States)

    Lin, Daniel; Li, Qing; Li, Wei; Swain, Michael

    2010-02-01

    Functionally graded material (FGM) had been developed as a potential implant material to replace titanium for its improved capability of initial osseointegration. The idea behind FGM dental implant is that its properties can be tailored in accordance with the biomechanical needs at different regions adapting to its hosting bony tissues, therefore creating an improved overall integration and stability in the entire restoration. However, there have been very few reports available so far on predicting bone remodeling induced by FGM dental implants. This article aims to evaluate bone remodeling when replacing the titanium with a hydroxyapatite/collagen (HAP/Col) FGM model. A finite element model was constructed in the buccal-lingual section of a dental implant-bone structure generated from in vivo CT scan images. The remodeling simulation was performed over a 4 year healing period. Comparisons were made between the titanium implant and various FGM implants of this model. The FGM implants showed an improved bone remodeling outcome. The study is expected to provide a basis for future development of FGM implants.

  18. Predictably replacing maxillary incisors with implants using 3-D planning and guided implant surgery.

    Science.gov (United States)

    Wöhrle, Peter S

    2014-01-01

    Replacement of multiple adjacent teeth in the esthetic zone with dental implants is a surgical and restorative challenge, especially when an esthetic outcome is essential. Sound diagnosis and treatment planning can be combined with use of cone-beam computed tomography (CBCT) and 3-dimensional (3-D) software to achieve desired results. Placement of implants using guided surgical templates is critical when there is limited space between adjacent teeth or limited bone volume. Slight deviations in implant positioning during placement can lead to implants being too close to adjacent teeth, resulting in bone loss, recession, and encroachment upon adjacent papillae. Placement of implants in anatomically deficient or compromised areas is difficult when using a freehand drill protocol, because attaining the necessary precision cannot be achieved routinely. Esthetically demanding patients require precise implant placement. Use of guided surgical planning and implant placement enables the surgeon to take maximum advantage of available bone in anatomically restricted areas. Restoratively, ideal implant placement facilitates rehabilitation; therefore, all parameters must be observed in order to achieve an esthetically pleasing final restoration.

  19. Dental implant as an option for tooth replacement: The awareness of patients at a tertiary hospital in a developing country

    Directory of Open Access Journals (Sweden)

    Olaide Shakeerah Gbadebo

    2014-01-01

    Full Text Available Aim: A survey was set out to evaluate the knowledge of patients about tooth replacement as a whole, and assess their awareness of implant-retained prosthesis as an option of tooth replacement. Materials and Methods: Information on sociodemographic characteristics, knowledge about implant-retained tooth as an option for missing tooth replacement, cost implication, source of information and knowledge about other options of tooth replacement were obtained from patients attending the dental clinics of the University College Hospital, Ibadan, using structured self-administered questionnaires. Data were analyzed using SPSS version 20. Result: A total of 220 patients aged 18-84 years with a mean age of 37.6 (±16.5 years participated in the study, with a male to female ratio of 1:1.1. The majority (92.5% knew that missing teeth can be replaced, while a significantly lower proportion (28.9% knew about dental implants as an option (P < 0.01. Dentists were the major source of information on dental implants (68%. Only 21 (36.8% of those who had heard about dental implant had knowledge about the cost (P < 0.000. Conclusion: A low level of awareness about dental implant as tooth replacement option exist in this environment, although most of the study participants were aware that missing teeth can be replaced.

  20. Cardiovascular implantable electronic device replacement infections and prevention: results from the REPLACE Registry.

    Science.gov (United States)

    Uslan, Daniel Z; Gleva, Marye J; Warren, David K; Mela, Theofanie; Chung, Mina K; Gottipaty, Venkateshwar; Borge, Richard; Dan, Dan; Shinn, Timothy; Mitchell, Kevin; Holcomb, Richard G; Poole, Jeanne E

    2012-01-01

    Infection following cardiovascular implantable electronic device (CIED) replacement is a serious complication, and rates of infection have increased. Analysis of procedural and clinical data from device replacement procedures collected by the REPLACE Registry may provide insights into infection prevention strategies and outcomes. We prospectively evaluated procedural complications in patients undergoing CIED replacement over 6 months from 72 U.S. sites. Major and minor infections were predefined and adjudicated by an independent blinded clinical events committee. Data regarding infection prevention strategies and infectious outcomes were analyzed for their potential relationships. A total of 1,744 patients were included in REPLACE. All patients received preoperative intravenous antibiotics and 68.7% received postoperative systemic antibiotic therapy. CIED infection developed in 22 patients (1.3%), of which 14 cases were major (0.8%, 95% confidence interval [CI] 0.4%-1.3%) and eight were minor (0.5%, 95% CI 0.2%-0.9%). Patients with infections were more likely to have had postoperative hematomas (five of 22 [22.7%] vs 17 of 1,722 [0.98%], P = 0.002). Participating sites experiencing infection rates >5% were more likely to use povidone-iodine for topical antisepsis, had lower implantation volume, and had patients with higher Charlson Comorbidity Index (2.79 vs 2.32, 95% CI for difference 0.08-0.86, P = 0.019). In this multicenter prospective study with 6 months of follow-up, infections associated with CIED replacements were surprisingly infrequent, possibly due to the use of preoperative antibiotics. Patients with infections were more likely to have had a postoperative hematoma, and sites with higher infection rates had sicker patients and lower overall procedural volume. ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.

  1. Neutrophil Responses to Sterile Implant Materials.

    Directory of Open Access Journals (Sweden)

    Siddharth Jhunjhunwala

    Full Text Available In vivo implantation of sterile materials and devices results in a foreign body immune response leading to fibrosis of implanted material. Neutrophils, one of the first immune cells to be recruited to implantation sites, have been suggested to contribute to the establishment of the inflammatory microenvironment that initiates the fibrotic response. However, the precise numbers and roles of neutrophils in response to implanted devices remains unclear. Using a mouse model of peritoneal microcapsule implantation, we show 30-500 fold increased neutrophil presence in the peritoneal exudates in response to implants. We demonstrate that these neutrophils secrete increased amounts of a variety of inflammatory cytokines and chemokines. Further, we observe that they participate in the foreign body response through the formation of neutrophil extracellular traps (NETs on implant surfaces. Our results provide new insight into neutrophil function during a foreign body response to peritoneal implants which has implications for the development of biologically compatible medical devices.

  2. Development of continuous implantable renal replacement: past and future.

    Science.gov (United States)

    Fissell, William H; Fleischman, Aaron J; Humes, H David; Roy, Shuvo

    2007-12-01

    Most of the 400,000+ patients in the United States with kidney failure depend on dialysis treatments in dedicated dialysis centers for 3 h to 5 h, usually 3 times a week, but they still suffer from accelerated cardiovascular disease and infections. Extended daily dialysis, for 6 to 8 hours every day, seems to be associated with better outcomes but would overwhelm the dialysis networks and severely limit patient activity. Technology to miniaturize and automate home dialysis will be necessary to offer extended daily dialysis to most dialysis patients. Miniaturization of existing hollow-fiber polymer membranes is constrained by requirements for high driving pressures for circulation and convective clearance. Recent advances in membrane technology based on microelectromechanical systems (MEMS) promise to enable the development of continuous implantable renal replacement therapy. Silicon nanoporous membranes with a highly monodisperse pore size distribution have been produced using protocols amenable to low-cost batch fabrication similar to those used to produce microelectronics. Hydraulic permeability of the flat-sheet membranes with critical pore sizes in the range of 8-100 nm has been measured to confirm that conventional fluid transport models are sufficiently accurate for predictive design for bulk liquid flow in an implantable hemofilter. Membrane biocompatibility was tested in vitro with human proximal tubule cells and revealed that silicon does not exhibit cytotoxicity, as evidenced by the formation of confluent cell layers with tight junctions and central cilia. Filtration characterization demonstrated that the nanoporous membranes exhibit size-dependent solute rejection in agreement with steric hindrance models. These advances in membrane technology are fundamentally enabling for a paradigm shift from an in-center to implantable dialysis system.

  3. Ion Implantation and Synthesis of Materials

    CERN Document Server

    Nastasi, Michael

    2006-01-01

    Ion implantation is one of the key processing steps in silicon integrated circuit technology. Some integrated circuits require up to 17 implantation steps and circuits are seldom processed with less than 10 implantation steps. Controlled doping at controlled depths is an essential feature of implantation. Ion beam processing can also be used to improve corrosion resistance, to harden surfaces, to reduce wear and, in general, to improve materials properties. This book presents the physics and materials science of ion implantation and ion beam modification of materials. It covers ion-solid interactions used to predict ion ranges, ion straggling and lattice disorder. Also treated are shallow-junction formation and slicing silicon with hydrogen ion beams. Topics important for materials modification, such as ion-beam mixing, stresses, and sputtering, are also described.

  4. Investigation of Biodentine as dentine replacement material.

    Science.gov (United States)

    Camilleri, Josette

    2013-07-01

    Biodentine was compared to glass ionomer and resin modified cements in an "open sandwich" restoration. Fuji IX, Vitrebond and Biodentine were characterised using various techniques. The effect of etching with 35% phosphoric acid was investigated by assessment of surface topography, Fourier transform infrared (FT-IR) spectroscopy, surface micro-hardness and micro-leakage using tagged carboxylated-modified fluorescent microspheres and tracing the presence of these particles with a confocal microscope. Acid etching resulted in erosion of the material surface with exposure of the glass particles in the glass ionomer-based materials. Biodentine exhibited a reduction in the chlorine peak and the calcium-silicon ratio. There was no difference in the micro-hardness in etched and un-etched materials. The FT-IR plots did not show any chemical changes caused by etching for all the materials investigated. Both Vitrebond and Fuji IX exhibited no leakage at the dentine to material interface while Biodentine exhibited leakage both when it was etched and also when the surface was left unprepared. The sandwich technique was effective and prevented micro-leakage with glass ionomer-based materials but micro-leakage occurred with Biodentine. Biodentine demonstrated both structural and chemical changes when etched with 37% phosphoric acid. Biodentine exhibited a lower calcium to silicon ratio and a reduction in the chloride peak height when etched. When used as a dentine replacement material in the sandwich technique overlayed with composite, significant leakage occurred at the dentine to material interface. On the other hand materials based on glass ionomer cement were etched successfully and no chemical and physical changes or micro-leakage were detected when the materials were used as bases under composite restorations. The micro-hardness of all the materials was unaffected by etching. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. 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

  6. Artificial implantation materials; Sztuczne materialy implantacyjne

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowska-Szumiel, M. [Akademia Medyczna, Warsaw (Poland)

    1997-10-01

    The radiation techniques for sterilization of orthopedic materials and high performance biomaterials have been reviewed. The radiation formulation of synthetic biomaterials for implantation and other medical use have been also performed. 18 refs, 3 tabs.

  7. In-situ photopolymerization and monitoring device for controlled shaping of tissue fillers, replacements, or implants

    Science.gov (United States)

    Schmocker, Andreas M.; Khoushabi, Azadeh; Bourban, Pierre-Etienne; Schizas, Constantin; Pioletti, Dominique; Moser, Christophe

    2015-03-01

    Photopolymerization is a common tool to harden materials initially in a liquid state. A surgeon can directly trigger the solidification of a dental implant or a bone or tissue filler simply by illumination. Traditionally, photopolymerization has been used mainly in dentistry. Over the last decade advances in material development including a wide range of biocompatible gel- and cement-systems open up a new avenue for in-situ photopolymerization. However, at the device level, surgical endoscopic probes are required. We present a miniaturized light probe where a photoactive material can be 1) mixed, pressurized and injected 2) photopolymerized or photoactivated and 3) monitored during the chemical reaction. The device enables surgeries to be conducted through a hole smaller than 1 mm in diameter. Beside basic injection mechanics, the tool consists of an optical fiber guiding the light required for photopolymerization and for chemical analysis. Combining photorheology and fluorescence spectroscopy, the current state of the photopolymerization is inferred and monitored in real time. Biocompatible and highly tuneable Poly-Ethylene-Glycol (PEG) hydrogels were used as the injection material. The device was tested on a model for intervertebral disc replacement. Gels were successfully implanted into a bovine caudal model and mechanically tested in-vitro during two weeks. The photopolymerized gel was evaluated at the tissue level (adherence and mechanical properties of the implant), at the cellular level (biocompatibility and cytotoxicity) and ergonomic level (sterilization procedure and feasibility study). This paper covers the monitoring aspect of the device.

  8. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

  9. Dental implants from functionally graded materials.

    Science.gov (United States)

    Mehrali, Mehdi; Shirazi, Farid Seyed; Mehrali, Mohammad; Metselaar, Hendrik Simon Cornelis; Kadri, Nahrizul Adib Bin; Osman, Noor Azuan Abu

    2013-10-01

    Functionally graded material (FGM) is a heterogeneous composite material including a number of constituents that exhibit a compositional gradient from one surface of the material to the other subsequently, resulting in a material with continuously varying properties in the thickness direction. FGMs are gaining attention for biomedical applications, especially for implants, owing to their reported superior composition. Dental implants can be functionally graded to create an optimized mechanical behavior and achieve the intended biocompatibility and osseointegration improvement. This review presents a comprehensive summary of biomaterials and manufacturing techniques researchers employ throughout the world. Generally, FGM and FGM porous biomaterials are more difficult to fabricate than uniform or homogenous biomaterials. Therefore, our discussion is intended to give the readers about successful and obstacles fabrication of FGM and porous FGM in dental implants that will bring state-of-the-art technology to the bedside and develop quality of life and present standards of care.

  10. Materials and technologies for soft implantable neuroprostheses

    Science.gov (United States)

    Lacour, Stéphanie P.; Courtine, Grégoire; Guck, Jochen

    2016-10-01

    Implantable neuroprostheses are engineered systems designed to restore or substitute function for individuals with neurological deficits or disabilities. These systems involve at least one uni- or bidirectional interface between a living neural tissue and a synthetic structure, through which information in the form of electrons, ions or photons flows. Despite a few notable exceptions, the clinical dissemination of implantable neuroprostheses remains limited, because many implants display inconsistent long-term stability and performance, and are ultimately rejected by the body. Intensive research is currently being conducted to untangle the complex interplay of failure mechanisms. In this Review, we emphasize the importance of minimizing the physical and mechanical mismatch between neural tissues and implantable interfaces. We explore possible materials solutions to design and manufacture neurointegrated prostheses, and outline their immense therapeutic potential.

  11. Replacing worn overdenture abutments of an unknown implant system by using laser welding: a clinical report.

    Science.gov (United States)

    Mohunta, Vrinda V; Stevenson, James A; Lee, Damian J

    2014-09-01

    This clinical report describes a procedure for replacing worn ball abutments with low-profile resilient abutments by using laser welding when the implant system for a mandibular implant-supported overdenture could not be identified. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  12. Materials characteristics of uncoated/ceramic-coated implant materials.

    Science.gov (United States)

    Lacefield, W R

    1999-06-01

    In this paper, the biocompatibility of dental implant materials is discussed in the context of both the mechanical characteristics of the materials and the type of surface presented to the surrounding tissues. The proper functioning of the implant depends on whether it possesses the strength necessary to withstand loading within the expected range, with other properties such as elongation being of importance in some instances. A suitable modulus of elasticity may be of major importance in situations when optimum load transmission from the implant into the surrounding bone is key to the successful functioning of the device. Dental implants present a wide range of surfaces to the surrounding tissues based on surface composition, texture, charge energy, and cleanliness (sterility). Metallic implants are characterized by protective oxide layers, but ion release is still common with these materials, and is a function of passivation state, composition, and corrosion potential. An effective surface treatment for titanium appears to be passivation or anodization in a suitable solution prior to implantation. Inert ceramic surfaces exhibit minimal ion release, but are similar to metals in that they do not form a high energy bond to the surrounding bone. Some of the newly developed dental implant alloys such as titanium alloys, which contain zirconium and niobium, and high-strength ceramics such as zirconia may offer some advantages (such as lower modulus of elasticity) over the conventional materials. Calcium phosphate ceramic coatings are commonly used to convert metallic surfaces into a more bioactive state and typically cause faster bone apposition. There is a wide range of ceramic coatings containing calcium and phosphorus, with the primary difference in many of these materials being in the rate of ion release. Although their long-term success rate is unknown, the calcium phosphate surfaces seem to have a higher potential for attachment of osteoinductive agents than do

  13. 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

  14. Root analog zirconia implants: true anatomical design for molar replacement--a case report.

    Science.gov (United States)

    Pirker, Wolfgang; Kocher, Alfred

    2011-01-01

    Replacement of lost teeth using oral implants is an accepted treatment modality with well-documented high long-term success rates. Conventional screw- or threaded cylinder-type implants have been used almost exclusively. Their incongruence with the extraction socket necessitates the use of a barrier membrane or bone augmentation to prevent down-growth of connective tissue or epithelium between the implant and socket. Although some minor changes in implant design have been made, the neck and abutment connection areas have not changed much in the past 30 years. Custom-made root analog implants have been employed clinically in rare instances; however, they yielded failure rates of up to 96% at 1 year of follow-up. So far, ovoid implants are the closest in design regarding resemblance to the natural tooth anatomy. Root analog zirconia implants with macroretentions were developed and produced for immediate single-stage replacement of missing or hopeless teeth. This article discusses the treatment and 3-year follow-up of a patient with such an implant for replacement of a maxillary molar.

  15. The AbioCor totally implantable replacement heart.

    Science.gov (United States)

    Holmes, Elena C

    2003-01-01

    An artificial heart with adequate circulatory support and an acceptable quality of life remains one of the holy grails of heart failure medicine and surgery. The totally implantable AbioCor is powered electrically via an external power source and has no skin-piercing cables. To date, seven critically ill patients with end-stage heart failure have been implanted with it. Four patients survived beyond 2 months, and two patients were discharged from the hospital. Both enjoyed improved quality of life with frequent social excursions; another patient is about to be discharged. While three patients died, early trials suggest that this device holds promise.

  16. An Automated Size Recognition Technique for Acetabular Implant in Total Hip Replacement

    CERN Document Server

    Shapi'i, Azrulhizam; Hasan, Mohammad Khatim; Kassim, Abdul Yazid Mohd; 10.5121/ijcsit.2011.3218

    2011-01-01

    Preoperative templating in Total Hip Replacement (THR) is a method to estimate the optimal size and position of the implant. Today, observational (manual) size recognition techniques are still used to find a suitable implant for the patient. Therefore, a digital and automated technique should be developed so that the implant size recognition process can be effectively implemented. For this purpose, we have introduced the new technique for acetabular implant size recognition in THR preoperative planning based on the diameter of acetabulum size. This technique enables the surgeon to recognise a digital acetabular implant size automatically. Ten randomly selected X-rays of unidentified patients were used to test the accuracy and utility of an automated implant size recognition technique. Based on the testing result, the new technique yielded very close results to those obtained by the observational method in nine studies (90%).

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

    Science.gov (United States)

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

    2014-02-01

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

  18. 21 CFR 872.3645 - Subperiosteal implant material.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3645 Subperiosteal implant material. (a) Identification. Subperiosteal implant material is a device composed of titanium or cobalt chrome molybdenum... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Subperiosteal implant material. 872.3645...

  19. Surgical aortic-valve replacement with a transcatheter implant.

    Science.gov (United States)

    Nowell, Justin L; Dewhurst, Alex; van Besouw, Jean-Pierre; Jahangiri, Marjan

    2011-04-01

    We describe a bailout procedure when surgical aortic-valve replacement was not possible due to severe calcification of the ascending aorta and the root and a very small annulus. A 21-mm CoreValve Revalving prosthesis was inserted via the aortotomy in the presence of a mitral prosthesis.

  20. Replacement of hopeless retained primary teeth by immediate dental implants: a case report.

    Science.gov (United States)

    de Oliveira, Rafael R; Macedo, Guilherme O; Muglia, Valdir A; Souza, Sérgio L S; Novaes, Arthur B; Taba, Mário

    2009-01-01

    Hopeless retained primary teeth without permanent successors represent a restorative challenge for clinicians, along with esthetic and functional problems for patients. While various treatment approaches for congenitally missing teeth have been proposed, the replacement of a missing tooth with a dental implant offers specific advantages, such as preservation of the alveolar crest and elimination of the need to restore the adjacent teeth, over other options for tooth replacement. The aim of this article was to illustrate the surgical and prosthetic treatment with implants of a patient with primary teeth without permanent successors.

  1. Selective laser sintering of calcium phosphate materials for orthopedic implants

    Science.gov (United States)

    Lee, Goonhee

    Two technologies, Solid Freeform Fabrication (SFF) and bioceramics are combined in this work to prepare bone replacement implants with complex geometry. SFF has emerged as a crucial technique for rapid prototyping in the last decade. Selective Laser Sintering (SLS) is one of the established SFF manufacturing processes that can build three-dimensional objects directly from computer models without part-specific tooling or human intervention. Meanwhile, there have been great efforts to develop implantable materials that can assist in regeneration of bone defects and injuries. However, little attention has been focused in shaping bones from these materials. The main thrust of this research was to develop a process that can combine those two separate efforts. The specific objective of this research is to develop a process that can construct bone replacement material of complex geometry from synthetic calcium phosphate materials by using the SLS process. The achievement of this goal can have a significant impact on the quality of health care in the sense that complete custom-fit bone and tooth structures suitable for implantation can be prepared within 24--48 hours of receipt of geometric information obtained either from patient Computed Tomographic (CT) data, from Computer Aided Design (CAD) software or from other imaging systems such as Magnetic Resonance Imaging (MRI) and Holographic Laser Range Imaging (HLRI). In this research, two different processes have been developed. First is the SLS fabrication of porous bone implants. In this effort, systematic procedures have been established and calcium phosphate implants were successfully fabricated from various sources of geometric information. These efforts include material selection and preparation, SLS process parameter optimization, and development of post-processing techniques within the 48-hour time frame. Post-processing allows accurate control of geometry and of the chemistry of calcium phosphate, as well as

  2. Off-pump replacement of the INCOR implantable axial-flow pump.

    Science.gov (United States)

    Nakashima, Kuniki; Kirsch, Matthias E W; Vermes, Emmanuelle; Rosanval, Odile; Loisance, Daniel

    2009-02-01

    Owing to the actual increase of mechanical circulatory support durations, total or partial replacement of ventricular assist devices (VADs) will most certainly have to be performed with increasing frequency. Herein we report the case of a patient in whom an INCOR (Berlin Heart AG, Berlin) implantable axial-flow pump was replaced without the use of cardiopulmonary bypass (CPB), underscoring some of the unique features provided by this system.

  3. Transcatheter aortic valve implantation vs. surgical aortic valve replacement for treatment of severe aortic stenosis

    DEFF Research Database (Denmark)

    Siontis, George C M; Praz, Fabien; Pilgrim, Thomas

    2016-01-01

    AIMS: In view of the currently available evidence from randomized trials, we aimed to compare the collective safety and efficacy of transcatheter aortic valve implantation (TAVI) vs. surgical aortic valve replacement (SAVR) across the spectrum of risk and in important subgroups. METHODS AND RESULTS...

  4. New-onset atrial fibrillation after surgical aortic valve replacement and transcatheter aortic valve implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav;

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...

  5. New-Onset Atrial Fibrillation After Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav;

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...

  6. New-Onset Atrial Fibrillation After Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...

  7. 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...

  8. 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...

  9. Economic evaluation of single-tooth replacement: dental implant versus fixed partial denture.

    Science.gov (United States)

    Kim, Younhee; Park, Joo-Yeon; Park, Sun-Young; Oh, Sung-Hee; Jung, YeaJi; Kim, Ji-Min; Yoo, Soo-Yeon; Kim, Seong-Kyun

    2014-01-01

    This study assessed the cost-effectiveness from a societal perspective of a dental implant compared with a three-unit tooth-supported fixed partial denture (FPD) for the replacement of a single tooth in 2010. A decision tree was developed to estimate cost-effectiveness over a 10-year period. The survival rates of single-tooth implants and FPDs were extracted from a meta-analysis of single-arm studies. Medical costs included initial treatment costs, maintenance costs, and costs to treat complications. Patient surveys were used to obtain the costs of the initial single-tooth implant or FPD. Maintenance costs and costs to treat complications were based on surveys of seven clinical experts at dental clinics or hospitals. Transportation costs were calculated based on the number of visits for implant or FPD treatment. Patient time costs were estimated using the number of visits and time required, hourly wage, and employment rate. Future costs were discounted by 5% to convert to present values. The results of a 10-year period model showed that a single dental implant cost US $261 (clinic) to $342 (hospital) more than an FPD and had an average survival rate that was 10.4% higher. The incremental cost-effectiveness ratio was $2,514 in a clinic and $3,290 in a hospital for a prosthesis in situ for 10 years. The sensitivity analysis showed that initial treatment costs and survival rate influenced the cost-effectiveness. If the cost of an implant were reduced to 80% of the current cost, the implant would become the dominant intervention. Although the level of evidence for effectiveness is low, and some aspects of single-tooth implants or FPDs, such as satisfaction, were not considered, this study will help patients requiring single-tooth replacement to choose the best treatment option.

  10. The Influence of Partial Knee Replacement Designs on Tensile Strain at Implant-Bone Interface

    Directory of Open Access Journals (Sweden)

    He Wang

    2012-01-01

    Full Text Available Partial knee replacement (PKR results in fast recovery and good knee mechanics and is ideal to treat medial knee osteoarthritis. Cementless PKR depends on bone growing into the implant surface for long-term fixation. Implant loosening may occur due to high tensile strain resulted from large mechanical loads during rehab exercises. The purpose of this study is to investigate whether external fixations such as superior screw and frontal flange could reduce the tensile strain at the implant-bone interface. Three medial PKRs were designed. The first PKR had no external fixations. A superior screw and a frontal flange were then added to the first PKR to form the second and third PKR designs, respectively. Finite element analysis was performed to examine the tensile strain at the implant-bone interface during weight-bearing exercises. The PKR with no external fixations exhibited high tensile strain at the anterior implant-bone interface. Both the screwed and flanged PKRs effectively reduced the tensile strain at the anterior implant-bone interface. Furthermore, the flanged PKR resulted in a more uniform reduction of the tensile strain than the screwed PKR. In conclusion, external fixations are necessary to alleviate tensile strain at the implant-bone interface during knee rehab exercises.

  11. The effect of mucosal cuff shrinkage around dental implants during healing abutment replacement.

    Science.gov (United States)

    Nissan, J; Zenziper, E; Rosner, O; Kolerman, R; Chaushu, L; Chaushu, G

    2015-10-01

    Soft tissue shrinkage during the course of restoring dental implants may result in biological and prosthodontic difficulties. This study was conducted to measure the continuous shrinkage of the mucosal cuff around dental implants following the removal of the healing abutment up to 60 s. Individuals treated with implant-supported fixed partial dentures were included. Implant data--location, type, length, diameter and healing abutments' dimensions--were recorded. Mucosal cuff shrinkage, following removal of the healing abutments, was measured in bucco-lingual direction at four time points--immediately after 20, 40 and 60 s. anova was used to for statistical analysis. Eighty-seven patients (49 women and 38 men) with a total of 311 implants were evaluated (120 maxilla; 191 mandible; 291 posterior segments; 20 anterior segments). Two-hundred and five (66%) implants displayed thick and 106 (34%) thin gingival biotype. Time was the sole statistically significant parameter affecting mucosal cuff shrinkage around dental implants (P < 0.001). From time 0 to 20, 40 and 60 s, the mean diameter changed from 4.1 to 4.07, 3.4 and 2.81 mm, respectively. The shrinkage was 1%, 17% and 31%, respectively. The gingival biotype had no statistically significant influence on mucosal cuff shrinkage (P = 0.672). Time required replacing a healing abutment with a prosthetic element should be minimised (up to 20/40 s), to avoid pain, discomfort and misfit.

  12. The short stem GHEs in total hip replacement – experience after 380 implantations

    Directory of Open Access Journals (Sweden)

    Ghanem, Mohamed

    2013-11-01

    Full Text Available Introduction: Standard straight stems have been recognized as a gold standard implant in the field of hip replacement surgery. However, lately uncemented bone-preserving short stems started to gain more and more popularity. This was reflected in the increasing variety of available models. Up till now, short and mid-term results are available.Patients and methods: In 2002, the cementless short stemmed GHEs was introduced. 380 patients were included in our study between 2002 and 2008. Only GHEs short stems were implanted. The clinical and radiological evaluations were performed in the Orthopaedic Department, Leipzig University Hospitals, on the average of 24 months (3 to 60 months postoperatively.Results: 365 primary implantations and 15 revision implantations were carried out. Average age 60 years. Favourable clinical and radiological outcome was seen in 361/380 patients (95%. Postoperative complications were seen in 19/380 patients (5%: 8 fissures/fractures (2.1%, 5 infections (1.3%, 4 aseptic loosenings (1.1%, 2 dislocations (0.5%.Conclusions: Short stem implants, including our own experience with GHEs model, are satisfying and promising. They represent a valuable supplementation of the treatment modalities in hip replacement surgery. However, long term results are still awaited.

  13. Three-dimensional printing and nanotechnology for enhanced implantable materials

    Science.gov (United States)

    Tappa, Karthik Kumar

    Orthopedic and oro-maxillofacial implants have revolutionized treatment of bone diseases and fractures. Currently available metallic implants have been in clinical use for more than 40 years and have proved medically efficacious. However, several drawbacks remain, such as excessive stiffness, accumulation of metal ions in surrounding tissue, growth restriction, required removal/revision surgery, inability to carry drugs, and susceptibility to infection. The need for additional revision surgery increases financial costs and prolongs recovery time for patients. These metallic implants are bulk manufactured and often do not meet patient's requirements. A surgeon must machine (cut, weld, trim or drill holes) them in order to best suit the patient specifications. Over the past few decades, attempts have been made to replace these metallic implants with suitable biodegradable materials to prevent secondary/revision surgery. Recent advances in biomaterials have shown multiple uses for lactic acid polymers in bone implant technology. However, a targeted/localized drug delivery system needs to be incorporated in these polymers, and they need to be customized to treat orthopedic implant-related infections and other bone diseases such as osteomyelitis, osteosarcoma and osteoporosis. Rapid Prototyping (RP) using additive manufacturing (AM) or 3D printing could allow customization of constructs for personalized medicine. The goal of this study was to engineer customizable and biodegradable implant materials that can elute bioactive compounds for personalized medicine and targeted drug delivery. Post-operative infections are the most common complications following dental, orthopedic and bone implant surgeries. Preventing post-surgical infections is therefore a critical need that current polymethylmethacrylate (PMMA) bone cements fail to address. Calcium Phosphate Cements (CPCs) are unique in their ability to crystallize calcium and phosphate salts into hydroxyapatite (HA) and

  14. Intervention for replacing missing teeth: Different types of implants - evidence summary of updated Cochrane review

    Directory of Open Access Journals (Sweden)

    Balendra Pratap Singh

    2015-01-01

    Full Text Available Around 1300 different types of dental implants are available worldwide and the implant manufacturers are resorting to aggressive marketing strategies; claiming their implants to provide a superior outcome. The clinician is left with a constant dilemma on which implant to choose for better clinical outcome and welfare of the patient. Moreover, in India, economical consideration is a concern too. The dentist has to select an implant that provides a good result and is economical. Cochrane systematic reviews provide the gold standard evidence for intervention, diagnosis, etc., and follow a strict quality control. A Cochrane systematic review was done to shed light on whether the different implant surface modifications, shapes or materials significantly influence clinical outcomes. All randomized controlled trials (RCTs till January 17, 2014 were searched and out of the 81 trials, only 27 met the inclusion criteria. This evidence summary from the review concludes that based on the available literature; there is no evidence of any one type of implant being superior to another. There is weak evidence showing roughened dental implants are more prone to bone loss due to periimplantitis. This review indicated that there is a need for well-designed RCTs, with long-term follow-up and low bias. Moreover, none of the included studies was from India, which also points out the need for improving the quality of RCTs conducted in India.

  15. The articular surface replacement implant recall: a United Kingdom district hospital experience.

    Science.gov (United States)

    Whitwell, George S; Shine, Ashokan; Young, Steve K

    2012-01-01

    We present our experience of the articular surface replacement (ASR) hip and the implant recall process. One hundred and twenty-one ASR components were implanted (21 resurfacing hip arthroplasty (RHA) and 100 ASR/XL modular total hip replacements). At the time of the implant recall in August 2010 there were 111 surviving hips (92%) with a mean follow-up of 44 months. Nine hips had been revised and one had been listed for revision surgery. Ninety-two percent of surviving implants were reviewed in the recall clinics, and blood metal ion levels or ultrasound scans were indicated in 38 hips (34%). Immediately after the recall process seven hips (6 ASR/XL and 1 RHA) were listed for revision and a further 9 were kept under close surveillance. One year after completion of the recall process 23 hips (19 ASR/XL and 4 RHA's) had been revised. A diagnosis of adverse reaction to metal debris (ARMD) was made at surgery in all but two hips. Our current revision rate for ASR RHA is 19% (mean follow-up 62 months, range 29-80) and for the ASR/XL is 19% (mean follow-up 53 months, range 10-80). The 5-year cumulative survival rates with revision for any reason for the ASR/XL, was 80.8% (95% confidence interval 72.0 - 89.5). Given experience elsewhere we expect this rate may increase significantly with time.

  16. Hydrogels as a Replacement Material for Damaged Articular Hyaline Cartilage

    Directory of Open Access Journals (Sweden)

    Charlotte M. Beddoes

    2016-06-01

    Full Text Available Hyaline cartilage is a strong durable material that lubricates joint movement. Due to its avascular structure, cartilage has a poor self-healing ability, thus, a challenge in joint recovery. When severely damaged, cartilage may need to be replaced. However, currently we are unable to replicate the hyaline cartilage, and as such, alternative materials with considerably different properties are used. This results in undesirable side effects, including inadequate lubrication, wear debris, wear of the opposing articular cartilage, and weakening of the surrounding tissue. With the number of surgeries for cartilage repair increasing, a need for materials that can better mimic cartilage, and support the surrounding material in its typical function, is becoming evident. Here, we present a brief overview of the structure and properties of the hyaline cartilage and the current methods for cartilage repair. We then highlight some of the alternative materials under development as potential methods of repair; this is followed by an overview of the development of tough hydrogels. In particular, double network (DN hydrogels are a promising replacement material, with continually improving physical properties. These hydrogels are coming closer to replicating the strength and toughness of the hyaline cartilage, while offering excellent lubrication. We conclude by highlighting several different methods of integrating replacement materials with the native joint to ensure stability and optimal behaviour.

  17. Ion implantation in crystalline and amorphous materials

    Science.gov (United States)

    Tasch, Al F.

    1998-05-01

    Ion implantation continues to be the selective doping technique of choice in silicon integrated circuit (IC) manufacturing, and its applications continue to grow in doping, damage gettering, and process simplification. However, in both technology and manufacturing equipment development there is a rapidly increasing need to understand in detail the dependence of implanted impurity profiles and implant-induced damage profiles in silicon on all key implant parameters. These reasons include largely reduced thermal budgets in IC processing, heavy emphasis on control of equipment and process costs, and the need for rigid manufacturing control. Towards this end, accurate, comprehensive, and computationally efficient models for ion implanted profiles (impurity and damage) in silicon are indispensable. These models greatly facilitate more timely technology development and implementation in manufacturing, improved manufacturing process control; and the development of new ion implantation tools can be executed more efficiently. This talk describes ion implant models and simulators developed in the ion implant modeling research/education project at the University of Texas at Austin. Physically based models for ion implantation into single-crystal Si have been developed for the commonly used implant species B, BF(2), As, P, and Si for the most commonly used implant energy ranges. These models have explicit dependence on the major implant parameters (energy, dose, tilt angle and rotation angle). In addition, the models have been extensively verified by the vast amount of experimental data which has been obtained in the experimental part of this project. The models have been extended down to ultra-low implant energies (model has been developed which accurately predicts as-implanted profiles for B and P up to at least 2.5 and 5 MeV, respectively. In addition, for energies below 200keV (the most commonly used energies), a rigorous physically based implant-induced damage model has

  18. Catheterization of the AbioCor™ Implantable Replacement Heart: Evaluation of the Unique Physiology Created by the Device

    OpenAIRE

    Delgado, Reynolds M.; Nawar, Mohamad; Loghin, Catalin; Myers, Timothy J.; Gregoric, Igor D.; Pool, Toni; Scroggins, Nancy; Radovancevic, Branislav; Frazier, O. H.

    2006-01-01

    We performed the 1st catheterization of an AbioCor™ implantable replacement heart, in a patient who had developed high right-sided pump pressures, to determine whether the high pressures were caused by graft kinking or obstruction.

  19. Replacement

    Directory of Open Access Journals (Sweden)

    S. Radhakrishnan

    2014-03-01

    Full Text Available The fishmeal replaced with Spirulina platensis, Chlorella vulgaris and Azolla pinnata and the formulated diet fed to Macrobrachium rosenbergii postlarvae to assess the enhancement ability of non-enzymatic antioxidants (vitamin C and E, enzymatic antioxidants (superoxide dismutase (SOD and catalase (CAT and lipid peroxidation (LPx were analysed. In the present study, the S. platensis, C. vulgaris and A. pinnata inclusion diet fed groups had significant (P < 0.05 improvement in the levels of vitamins C and E in the hepatopancreas and muscle tissue. Among all the diets, the replacement materials in 50% incorporated feed fed groups showed better performance when compared with the control group in non-enzymatic antioxidant activity. The 50% fishmeal replacement (best performance diet fed groups taken for enzymatic antioxidant study, in SOD, CAT and LPx showed no significant increases when compared with the control group. Hence, the present results revealed that the formulated feed enhanced the vitamins C and E, the result of decreased level of enzymatic antioxidants (SOD, CAT and LPx revealed that these feeds are non-toxic and do not produce any stress to postlarvae. These ingredients can be used as an alternative protein source for sustainable Macrobrachium culture.

  20. Use of a trabecular metal implant in ankle arthrodesis after failed total ankle replacement

    Science.gov (United States)

    2010-01-01

    Background and purpose Arthrodesis after failed total ankle replacement is complicated and delayed union, nonunion, and shortening of the leg often occur—especially with large bone defects. We investigated the use of a trabecular metal implant and a retrograde intramedullary nail to obtain fusion. Patients and methods 13 patients with a migrated or loose total ankle implant underwent arthrodesis with the use of a retrograde intramedullary nail through a trabecular metal Tibial Cone. The mean follow-up time was 1.4 (0.6–3.4) years. Results At the last examination, 7 patients were pain-free, while 5 had some residual pain but were satisfied with the procedure. 1 patient was dissatisfied and experienced pain and swelling when walking. The implant-bone interfaces showed no radiographic zones or gaps in any patient, indicating union. Interpretation The method is a new way of simplifying and overcoming some of the problems of performing arthrodesis after failed total ankle replacement. PMID:21067435

  1. Surgical double valve replacement after transcatheter aortic valve implantation and interventional mitral valve repair.

    Science.gov (United States)

    Wendeborn, Jens; Donndorf, Peter; Westphal, Bernd; Steinhoff, Gustav

    2013-11-01

    Transcatheter aortic valve implantation, as well as interventional mitral valve repair, offer reasonable therapeutic options for high-risk surgical patients. We report a rare case of early post-interventional aortic valve prosthesis migration to the left ventricular outflow tract, with paravalvular leakage and causing severe mitral valve regurgitation. Initial successful interventional mitral valve repair using a clipped edge-to-edge technique revealed, in a subsequent procedure, the recurrence of mitral valve regurgitation leading to progressive heart failure and necessitating subsequent surgical aortic and mitral valve replacement.

  2. APPLICATION OF A BIODEGRADABLE MATERIAL FOR BONE REPLACEMENT IN TRAUMATOLOGY

    Directory of Open Access Journals (Sweden)

    T. V. Druzhinina

    2014-01-01

    Full Text Available 20 men (medium age (31.5 ± 13.5 years were studied. All patients underwent arthroscopic auditing plastic anterior cruciate ligament of the knee. Osteoregeneration dynamics were determined by biochemical testing of blood serum and X-ray computed tomography (CT of the fracture in 1–4 months after surgery. As a result, an estimation of the bone tissue reparative regeneration according to CT data in 10 patients with a defect of the patella, treated with the material is provided. The obtained results of the clinical study indicate the reparative effect of the biodegradable material for bone replacing on bone regeneration

  3. In-situ photopolymerized and monitored implants: successful application to an intervertebral disc replacement

    Science.gov (United States)

    Schmocker, Andreas M.; Khoushabi, Azadeh; Bourban, Pierre-Etienne; Schizas, Constantin; Pioletti, Dominique; Moser, Christophe

    2016-02-01

    Photopolymerization is a common method to harden materials initially in a liquid state. A surgeon can directly trigger the solidification of a dental implant or a bone or tissue filler by using ultra-violet light. Traditionally, photopolymerization has been used mainly in dentistry. Over the last decade advances in material development including a wide range of biocompatible gel- and cement-systems open up a new avenue for in-situ photopolymerization. We designed a miniaturized light probe where a photoactive material can be 1) mixed, pressurized and injected 2) photopolymerized or photoactivated and 3) monitored during the chemical reaction. The device enables surgeries to be conducted through a hole smaller than 500 μm in diameter. Using a combination of Raman and fluorescence spectroscopy, the current state of the photopolymerization was inferred and monitored in real time within an in-vitro tissue model. It was also possible to determine roughly the position of the probe within the tissue cavity by analysing the fluorescence signal. Using the technique hydrogels were successfully implanted into a bovine intervertebral disc model. Mechanical tests could not obstruct the functionality of the implant. Finally, the device was also used for other application such as the implantation of a hydrogel into an aneurysm tissue cavity which will be presented at the conference.

  4. Novel surface coating materials for endodontic dental implant

    Energy Technology Data Exchange (ETDEWEB)

    Fathi, M.H. [Isfahan Univ. of Technology, Materials Engineering Dept., Isfahan (Iran, Islamic Republic of); Mortazavi, V.; Moosavi, S.B. [Isfahan Univ. of Medical Sciences, Faculty of Dentistry, Isfahan (Iran, Islamic Republic of)

    2003-07-01

    The aim of this study was to design and produce novel coating materials in order to obtain two goals including; improvement of the corrosion behavior of metallic dental endodontic implant and the bone osteointegration simultaneously. Stainless steel 316L (SS) was used as a metallic substrate and a novel Hydroxyapatite/Titanium (HA/Ti) composite coating was prepared on it. Structural characterization techniques including XRD, SEM and EDX were utilized to investigate the microstructure and morphology of the coating. Electrochemical tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility. Two types of endodontic implants including; SS with and without (HA/Ti) composite coating were prepared and subsequently implanted in the mandibular canine of 20 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, osteointegration evaluation and histopathological interpretation was carried out using SEM and optical microscopy. Results indicate that the novel HA/Ti composite coating improves the corrosion behavior and biocompatibility of SS endodontic dental implant. The clinical evaluation (in vivo test) results showed that there was significant difference in osteointegration between coated and uncoated endodontic dental implants and average bone osteointegration of coated implants were more than uncoated implants. The histopathological results and bone tissue response to the coated implants was acceptable and it was concluded that HA/Ti composite coated SS could be used as well as an endodontic dental implant. (author)

  5. COMPARATIVE CHARACTERISTICS OF MATERIALS USED IN DENTAL IMPLANTATION

    Directory of Open Access Journals (Sweden)

    A. A. Yegorov

    2014-01-01

    Full Text Available The objective of the research is a review of some characteristics of dental implants’ products and an analysis of prospects of using them in modern medicine.Dental implantation as a high-technology method of restoring the natural anatomical structure has no competitors at present. The advantages of dental implants consist in their high operational dependability, a longer life time, a higher functionality and a lesser rate of complications as compared to the use of complete or bridge prostheses.The materials used in dental implantation for this purpose are rather diverse. Doctors using them rely on extensive clinical experience, a developed industry of accessory materials, instruments, that is everything that ensures comfortable work and conveniences for the patient.At the same time, the data mentioned in the article testify to the effect that ceramic implants as compared to titanium alloy implants have comparable or better indices. This is guaranteed, for example, by the requirements of the new international standard ISO6474-2:2012: first-rate strength and wear resistance; thermal stability and corrosion resistance; ceramics’ four point bending strength over 750 MPa.The result of the conducted analysis is a review of using various materials in dental implantation. The author compares the aesthetic indices and durability of titanium or metal alloy implants to those of ceramic ones. The comparison shows that, under the current level of ceramic materials’ structural property, it is actual for dentistry to develop its own methodological approaches in relation to a wide use of ceramic implants and creation of various ceramic mono-implants with the purpose of improving the results of treatment of patients, suffering from secondary partial or complete adentia accompanied by bone tissue deficiency, by applying the methods of dental implantation.

  6. Multisite Infection with Mycobacterium abscessus after Replacement of Breast Implants and Gluteal Lipofilling.

    Science.gov (United States)

    Rüegg, Eva; Cheretakis, Alexandre; Modarressi, Ali; Harbarth, Stephan; Pittet-Cuénod, Brigitte

    2015-01-01

    Introduction. Medical tourism for aesthetic surgery is popular. Nontuberculous mycobacteria (NTM) occasionally cause surgical-site infections. As NTM grow in biofilms, implantations of foreign bodies are at risk. Due to late manifestation, infections occur when patients are back home, where they must be managed properly. Case Report. A 39-year-old healthy female was referred for acute infection of the right gluteal area. Five months before, she had breast implants replacement, abdominal liposuction, and gluteal lipofilling in Mexico. Three months postoperatively, implants were removed for NTM-infection in Switzerland. Adequate antibiotic treatment was stopped after seven days for drug-related hepatitis. At entrance, gluteal puncture for bacterial analysis was performed. MRI showed large subcutaneous collection. Debridement under general anaesthesia was followed by open wound management. Total antibiotic treatment was 20 weeks. Methods. Bacterial analysis of periprosthetic and gluteal liquids included Gram-stain plus acid-fast stain, and aerobic, anaerobic and mycobacterial cultures.  Results. In periprosthetic fluid, Mycobacterium abscessus, Propionibacterium, and Staphylococcus epidermidis were identified. The same M. abscessus strain was found gluteally. The gluteal wound healed within six weeks. At ten months' follow-up, gluteal asymmetry persists for deep scarring. Conclusion. This case presents major complications of multisite aesthetic surgery. Surgical-site infections in context of medical tourism need appropriate bacteriological investigations, considering potential NTM-infections.

  7. Multisite Infection with Mycobacterium abscessus after Replacement of Breast Implants and Gluteal Lipofilling

    Directory of Open Access Journals (Sweden)

    Eva Rüegg

    2015-01-01

    Full Text Available Introduction. Medical tourism for aesthetic surgery is popular. Nontuberculous mycobacteria (NTM occasionally cause surgical-site infections. As NTM grow in biofilms, implantations of foreign bodies are at risk. Due to late manifestation, infections occur when patients are back home, where they must be managed properly. Case Report. A 39-year-old healthy female was referred for acute infection of the right gluteal area. Five months before, she had breast implants replacement, abdominal liposuction, and gluteal lipofilling in Mexico. Three months postoperatively, implants were removed for NTM-infection in Switzerland. Adequate antibiotic treatment was stopped after seven days for drug-related hepatitis. At entrance, gluteal puncture for bacterial analysis was performed. MRI showed large subcutaneous collection. Debridement under general anaesthesia was followed by open wound management. Total antibiotic treatment was 20 weeks. Methods. Bacterial analysis of periprosthetic and gluteal liquids included Gram-stain plus acid-fast stain, and aerobic, anaerobic and mycobacterial cultures.  Results. In periprosthetic fluid, Mycobacterium abscessus, Propionibacterium, and Staphylococcus epidermidis were identified. The same M. abscessus strain was found gluteally. The gluteal wound healed within six weeks. At ten months’ follow-up, gluteal asymmetry persists for deep scarring. Conclusion. This case presents major complications of multisite aesthetic surgery. Surgical-site infections in context of medical tourism need appropriate bacteriological investigations, considering potential NTM-infections.

  8. Bicompartmental individualized knee replacement : Use of patient-specific implants and instruments (iDuo™).

    Science.gov (United States)

    Steinert, A F; Beckmann, J; Holzapfel, B M; Rudert, M; Arnholdt, J

    2017-02-01

    Bicompartmental knee replacement in patients with combined osteoarthritis (OA) of the medial or lateral and patellofemoral compartment. Patient-specific instruments and implants (ConforMIS iDuo™) with a planning protocol for optimal implant fit. Bicompartmental OA of the knee (Kellgren & Lawrence stage IV) affecting both the medial or lateral and patellofemoral compartment after unsuccessful conservative or joint-preserving surgery. Tricompartmental OA, knee ligament instabilities, knee deformities >15° (varus, valgus, extension deficit). Relative contraindication: body mass index >40; prior unicompartmental knee replacement or osteotomies. Midline or parapatellar medial skin incision, medial arthrotomy; identify mechanical contact zone of the intact femoral condyle (linea terminalis); remove remaining cartilage and all osteophytes that may interfere with the correct placement of the individually designed instruments. Balance knee in extension with patient-specific balancing chips. Resection of proximal tibia with an individual cutting block; confirm axial alignment using an extramedullary alignment guide, balance flexion gap using spacer blocks in 90° flexion. Final femur preparation with resection of the anterior trochlea. After balancing and identification of insert heights, final tibial preparation is performed. Implant is cemented in 45° of knee flexion. Remove excess cement and final irrigation, followed by closure. Sterile wound dressing; compressive bandage. No limitation of active/passive range of motion (ROM). Partial weight bearing the first 2 weeks, then transition to full weight bearing. Follow-up directly after surgery, at 12 and 52 weeks, then every 1-2 years. In all, 44 patients with bicompartmental OA of the medial and patellofemoral compartment were treated. Mean age 59 years. Minimum follow-up 12 months. Implant converted to TKA due to tibial loosening (1 patient); patella resurfacing (3 patients). No further revisions or

  9. UHMWPE-based nanocomposite as a material for damaged cartilage replacement

    Energy Technology Data Exchange (ETDEWEB)

    Senatov, F.S., E-mail: Senatov@misis.ru [National University of Science and Technology “MISIS”, 119049, Leninskiy pr. 4, Moscow (Russian Federation); Kopylov, A.N.; Anisimova, N.Yu.; Kiselevsky, M.V. [N.N. Blokhin Russian Cancer Research Center, 115478, Kashirskoye sh. 23, Moscow (Russian Federation); Maksimkin, A.V. [National University of Science and Technology “MISIS”, 119049, Leninskiy pr. 4, Moscow (Russian Federation)

    2015-03-01

    In the present work dispersion-strengthened nanocomposites based on ultra-high molecular weight polyethylene (UHMWPE) after mechanical activation were studied. Mechanical activation was performed for hardening of the boundaries between the polymer particles, reducing the fusion defects and increasing of wear-resistance. Three types of samples were prepared: UHMWPE, UHMWPE/Al{sub 2}O{sub 3} nanocomposite and UHMWPE/Al{sub 2}O{sub 3} nanocomposite after mechanical activation. UHMWPE/Al{sub 2}O{sub 3} nanocomposites prepared with mechanical activation show the best mechanical properties in compression and higher wear-resistance. UHMWPE/Al{sub 2}O{sub 3} nanocomposites prepared with mechanical activation were chosen for in vivo study by orthotopical transplantation in rats. Animals' activity has been being monitored for 60 days after surgery. No signs of inflammation, cellular infiltration, destruction of material or bone–cartilage defect were found. Implanted sample has not changed its position of implantation, there were no any shifts. Obtained data shows that UHMWPE-based nanocomposite is a promising material for creating bioimplants for cartilage defect replacement. - Highlights: • Mechanical activation of UHMWPE composite leads to changing of fracture mechanism. • Mechanical activation leads to increasing of wear-resistance of UHMWPE composite. • The presence of Al{sub 2}O{sub 3} in grain boundaries of UHMWPE inhibits crack growth. • Complete integration of UHMWPE-based implant in cartilage defect of rat was shown. • UHMWPE/Al{sub 2}O{sub 3} nanocomposite may be recommended for use in cartilage replacement.

  10. Accuracy of different impression materials in parallel and nonparallel implants

    Science.gov (United States)

    Vojdani, Mahroo; Torabi, Kianoosh; Ansarifard, Elham

    2015-01-01

    Background: A precise impression is mandatory to obtain passive fit in implant-supported prostheses. The aim of this study was to compare the accuracy of three impression materials in both parallel and nonparallel implant positions. Materials and Methods: In this experimental study, two partial dentate maxillary acrylic models with four implant analogues in canines and lateral incisors areas were used. One model was simulating the parallel condition and the other nonparallel one, in which implants were tilted 30° bucally and 20° in either mesial or distal directions. Thirty stone casts were made from each model using polyether (Impregum), additional silicone (Monopren) and vinyl siloxanether (Identium), with open tray technique. The distortion values in three-dimensions (X, Y and Z-axis) were measured by coordinate measuring machine. Two-way analysis of variance (ANOVA), one-way ANOVA and Tukey tests were used for data analysis (α = 0.05). Results: Under parallel condition, all the materials showed comparable, accurate casts (P = 0.74). In the presence of angulated implants, while Monopren showed more accurate results compared to Impregum (P = 0.01), Identium yielded almost similar results to those produced by Impregum (P = 0.27) and Monopren (P = 0.26). Conclusion: Within the limitations of this study, in parallel conditions, the type of impression material cannot affect the accuracy of the implant impressions; however, in nonparallel conditions, polyvinyl siloxane is shown to be a better choice, followed by vinyl siloxanether and polyether respectively. PMID:26288620

  11. Utilization of Palm Oil Clinker as Cement Replacement Material

    Directory of Open Access Journals (Sweden)

    Jegathish Kanadasan

    2015-12-01

    Full Text Available The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with palm oil clinker powder as a binder material in self-compacting mortar. The fresh, hardened and microstructure properties were evaluated throughout this study. In addition, sustainability component analysis was also carried out to assess the environmental impact of introducing palm oil clinker powder as a replacement material for cement. It can be inferred that approximately 3.3% of cement production can be saved by substituting palm oil clinker powder with cement. Reducing the utilization of cement through a high substitution level of this waste material will also help to reduce carbon emissions by 52%. A cleaner environment free from pollutants can be created to ensure healthier living. Certain industries may benefit through the inclusion of this waste material as the cost and energy consumption of the product can be minimized.

  12. A personalized 3D-printed prosthetic joint replacement for the human temporomandibular joint: From implant design to implantation.

    Science.gov (United States)

    Ackland, David C; Robinson, Dale; Redhead, Michael; Lee, Peter Vee Sin; Moskaljuk, Adrian; Dimitroulis, George

    2017-05-01

    Personalized prosthetic joint replacements have important applications in cases of complex bone and joint conditions where the shape and size of off-the-shelf components may not be adequate. The objective of this study was to design, test and fabricate a personalized 3D-printed prosthesis for a patient requiring total joint replacement surgery of the temporomandibular joint (TMJ). The new 'Melbourne' prosthetic TMJ design featured a condylar component sized specifically to the patient and fixation screw positions that avoid potential intra-operative damage to the mandibular nerve. The Melbourne prosthetic TMJ was developed for a 58-year-old female recipient with end-stage osteoarthritis of the TMJ. The load response of the prosthesis during chewing and a maximum-force bite was quantified using a personalized musculoskeletal model of the patient's masticatory system developed using medical images. The simulations were then repeated after implantation of the Biomet Microfixation prosthetic TMJ, an established stock device. The maximum condylar stresses, screw stress and mandibular stress at the screw-bone interface were lower in the Melbourne prosthetic TMJ (259.6MPa, 312.9MPa and 198.4MPa, respectively) than those in the Biomet Microfixation device (284.0MPa, 416.0MPa and 262.2MPa, respectively) during the maximum-force bite, with similar trends also observed during the chewing bite. After trialing surgical placement and evaluating prosthetic TMJ stability using cadaveric specimens, the prosthesis was fabricated using 3D printing, sterilized, and implanted into the female recipient. Six months post-operatively, the prosthesis recipient had a normal jaw opening distance (40.0 mm), with no complications identified. The new design features and immediate load response of the Melbourne prosthetic TMJ suggests that it may provide improved clinical and biomechanical joint function compared to a commonly used stock device, and reduce risk of intra-operative nerve damage

  13. Replace种植系统在即刻种植中的临床应用研究%Clinical application of Replace implant system in the immediate implantation

    Institute of Scientific and Technical Information of China (English)

    张庆元; 张兆强; 张清彬; 刘佳钰

    2012-01-01

    目的:评价Replace种植系统应用于即刻种植的临床效果.方法:收集2006年2月~2008年2月期间具有即刻种植适应症的28例患者,行Replace种植系统植入术,术后3~6个月根据临床和影像学结果行二期手术及上部结构修复,随访观察18~36个月(平均15个月).结果:共植入47枚种植体,其中45枚获得成功,在随访期内无明显并发症,种植体负重后第1年牙槽骨吸收水平<1 mm.1例糖尿病患者2枚种植体于二期修复后7周脱落,成功率为95.74%(45/47).种植体周围龈炎4枚,烤瓷冠崩瓷2枚.结论:Replace即刻种植可缩短患者缺牙时间,减缓牙槽嵴吸收,患者满意度较高,但必须严格掌握适应症.%Objective: To evaluate the clinical effect of Replace implant system in application of the immediate implantation. Method:The Replace implant system was implanted in 28 patients who adapted to immediate implantation during February in 2006 to February in 2008. The dental implant rehabilitation was administered 3-6 months after the implant surgery in accordance lo the clinical and radiographic parameters. The clinical effect was followed up over 18-36 months (average IS months). Result:45 of all the 47 implants were successive and without obvious complication in the follow-up period t the absorption level of alveolar bone was less than I mm in the first year after rehabilitation. 2 implants embedded in the patient with diabetes dropped 7 weeks after the rehabilitation. The success rate was 95.74 % (45 / 47). There were 4 implants involved with peri-implant mucositis and 2 metal-porcelain full crowns yielded ceramic chipping. Conclusion: Immediate implantation with the Replace system could shorten the anodonlia time and slow down the absorption pace of alveolar bone. Patients were highly satisfied with the immediate implantation, However.the indication must be controlled strictly.

  14. Bone graft materials in fixation of orthopaedic implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    2013-01-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many...... orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include...... bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA...

  15. 10 CFR 35.75 - Release of individuals containing unsealed byproduct material or implants containing byproduct...

    Science.gov (United States)

    2010-01-01

    ... material or implants containing byproduct material. 35.75 Section 35.75 Energy NUCLEAR REGULATORY... containing unsealed byproduct material or implants containing byproduct material. (a) A licensee may... material or implants containing byproduct material if the total effective dose equivalent to any...

  16. Aortic valve stenosis after previous coronary bypass: Transcatheter valve implantation or aortic valve replacement?

    Directory of Open Access Journals (Sweden)

    Jegaden Olivier

    2012-05-01

    Full Text Available Abstract We report a prospective comparison between transcatheter valve implantation (TAVI, n = 13 and surgical aortic valve replacement (AVR, n = 10 in patients with severe aortic valve stenosis and previous coronary bypass surgery (CABG. All patients had at least bilateral patent internal thoracic arteries bypass without indication of repeat revascularization. After a similar post-procedure outcome, despite one early death in TAVI group, the 1-year survival was 100% in surgical group and in transfemoral TAVI group, and 73% in transapical TAVI group. When previous CABG is the lone surgical risk factor, indications for a TAVI procedure have to be cautious, specially if transfemoral approach is not possible.

  17. Update on Renal Replacement Therapy: Implantable Artificial Devices and Bioengineered Organs.

    Science.gov (United States)

    Attanasio, Chiara; Latancia, Marcela T; Otterbein, Leo E; Netti, Paolo A

    2016-08-01

    Recent advances in the fields of artificial organs and regenerative medicine are now joining forces in the areas of organ transplantation and bioengineering to solve continued challenges for patients with end-stage renal disease. The waiting lists for those needing a transplant continue to exceed demand. Dialysis, while effective, brings different challenges, including quality of life and susceptibility to infection. Unfortunately, the majority of research outputs are far from delivering satisfactory solutions. Current efforts are focused on providing a self-standing device able to recapitulate kidney function. In this review, we focus on two remarkable innovations that may offer significant clinical impact in the field of renal replacement therapy: the implantable artificial renal assist device (RAD) and the transplantable bioengineered kidney. The artificial RAD strategy utilizes micromachining techniques to fabricate a biohybrid system able to mimic renal morphology and function. The current trend in kidney bioengineering exploits the structure of the native organ to produce a kidney that is ready to be transplanted. Although these two systems stem from different technological approaches, they are both designed to be implantable, long lasting, and free standing to allow patients with kidney failure to be autonomous. However, for both of them, there are relevant issues that must be addressed before translation into clinical use and these are discussed in this review.

  18. Long-term implant-bone fixation of the femoral component in total knee replacement.

    Science.gov (United States)

    Cristofolini, L; Affatato, S; Erani, P; Leardini, W; Tigani, D; Viceconti, M

    2008-04-01

    Success of total knee replacement (TKR) depends on the prosthetic design. Aseptic loosening of the femoral component is a significant failure mode that has received little attention. Despite the clinical relevance of failures, no protocol is available to test long-term implant-bone fixation of TKR in vitro. The scope of this work was to develop and validate a protocol to assess pre-clinically the fixation of TKR femoral components. An in vitro protocol was designed to apply a simplified but relevant loading profile using a 6-degrees-of-freedom knee simulator for 1,000000 cycles. Implant-bone inducible micromotions and permanent migrations were measured at three locations throughout the test. After test completion, fatigue damage in the cement was quantified. The developed protocol was successfully applied to a commercial TKR. Additional tests were performed to exclude artefacts due to swelling or creep of the composite femur models. The components migrated distally; they tilted towards valgus in the frontal plane and in extension in the sagittal plane. The migration patterns were consistent with clinical roentgen-stereophotogrammetric recordings with TKR. Additional indicators were proposed that could quantify the tendency to loosen/stabilize. The type and amount of damage found in the cement, as well as the migration patterns, were consistent with clinical experience with the specific TKR investigated. The proposed pre-clinical test yielded repeatable results, which were consistent with the clinical literature. Therefore, its relevance and reliability was proved.

  19. Transcatheter aortic valve implantation versus surgical aortic valve replacement for severe aortic stenosis: a meta analysis

    Institute of Scientific and Technical Information of China (English)

    WU Yi-cheng; ZHANG Jian-feng; SHEN Wei-feng; ZHAO Qiang

    2013-01-01

    Background Transcatheter aortic valve implantation (TAVI) has emerged as the treatment choice for non-operable patients with severe symptomatic aortic stenosis (AS) and may be a good alternative to surgery for those at very high or prohibitive surgical risk.We performed a meta-analysis to evaluate the comparative benefits of TAVI versus surgical aortic valve replacement (SAVR) in patients with severe AS.Methods A comprehensive literature search of PubMed,Embase,ScienceDirect and Cochrane Central Register of Controlled trials was performed,and randomized trials as well as cohort studies with propensity score analysis were included.Results One randomized trial (n=699) and six retrospective cohort studies (n=781) were selected for meta-analysis.Mortality at 30-day and 1-year follow-up was comparable between TAVI and SAVR.Despite similar incidences of stroke,myocardial infarction,re-operation for bleeding,and renal failure requiring dialysis,TAVI was associated with a lower occurrence rate of new-onset atrial fibrillation (OR 0.51,95% CI 0.33-0.78) and shorter procedural time (mean difference -67.50 minutes,95% CI-87.20 to-47.81 minutes).Post-operative aortic regurgitation and permanent pacemaker implantation were more common in patients after TAVI than in those with SAVR (OR 5.53,95% CI 3.41-8.97; OR 1.71,95% Cl 1.02-2.84,respectively).Conclusion In patients with severe symptomatic AS,TAVI and SAVR did not differ with respect to short-and mid-term survival,but the incidence of permanent pacemaker implantation and post-procedural aortic regurgitation remain relatively high after TAVI.

  20. Total hip replacement: A meta-analysis to evaluate survival of cemented, cementless and hybrid implants

    Science.gov (United States)

    Phedy, Phedy; Ismail, H Dilogo; Hoo, Charles; Djaja, Yoshi P

    2017-01-01

    AIM To determine whether cemented, cementless, or hybrid implant was superior to the other in terms of survival rate. METHODS Systematic searches across MEDLINE, CINAHL, and Cochrane that compared cemented, cementless and hybrid total hip replacement (THR) were performed. Two independent reviewers evaluated the risk ratios of revision due to any cause, aseptic loosening, infection, and dislocation rate of each implants with a pre-determined form. The risk ratios were pooled separately for clinical trials, cohorts and registers before pooled altogether using fixed-effect model. Meta-regressions were performed to identify the source of heterogeneity. Funnel plots were analyzed. RESULTS Twenty-seven studies comprising 5 clinical trials, 9 cohorts, and 13 registers fulfilled the research criteria and analyzed. Compared to cementless THR, cemented THR have pooled RR of 0.47 (95%CI: 0.45-0.48), 0.9 (0.84-0.95), 1.29 (1.06-1.57) and 0.69 (0.6-0.79) for revision due to any reason, revision due to aseptic loosening, revision due to infection, and dislocation respectively. Compared to hybrid THR, the pooled RRs of cemented THR were 0.82 (0.76-0.89), 2.65 (1.14-6.17), 0.98 (0.7-1.38), and 0.67 (0.57-0.79) respectively. Compared to hybrid THR, cementless THR had RRs of 0.7 (0.65-0.75), 0.85 (0.49-1.5), 1.47 (0.93-2.34) and 1.13 (0.98-1.3). CONCLUSION Despite the limitations in this study, there was some tendency that cemented fixation was still superior than other types of fixation in terms of implant survival.

  1. Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

    Directory of Open Access Journals (Sweden)

    Zeeshan Sheikh

    2015-05-01

    Full Text Available Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses.

  2. UHMWPE-based nanocomposite as a material for damaged cartilage replacement.

    Science.gov (United States)

    Senatov, F S; Kopylov, A N; Anisimova, N Yu; Kiselevsky, M V; Maksimkin, A V

    2015-03-01

    In the present work dispersion-strengthened nanocomposites based on ultra-high molecular weight polyethylene (UHMWPE) after mechanical activation were studied. Mechanical activation was performed for hardening of the boundaries between the polymer particles, reducing the fusion defects and increasing of wear-resistance. Three types of samples were prepared: UHMWPE, UHMWPE/Al2O3 nanocomposite and UHMWPE/Al2O3 nanocomposite after mechanical activation. UHMWPE/Al2O3 nanocomposites prepared with mechanical activation show the best mechanical properties in compression and higher wear-resistance. UHMWPE/Al2O3 nanocomposites prepared with mechanical activation were chosen for in vivo study by orthotopical transplantation in rats. Animals' activity has been being monitored for 60days after surgery. No signs of inflammation, cellular infiltration, destruction of material or bone-cartilage defect were found. Implanted sample has not changed its position of implantation, there were no any shifts. Obtained data shows that UHMWPE-based nanocomposite is a promising material for creating bioimplants for cartilage defect replacement.

  3. Load transfer in the proximal tibia following implantation with a unicompartmental knee replacement: a static snapshot.

    Science.gov (United States)

    Simpson, D J; Kendrick, B J L; Dodd, C A F; Price, A J; Gill, H S; Murray, D W

    2011-05-01

    Unicompartmental knee replacement (UKR) is an appealing alternative to total knee replacement when the patient has isolated medial compartment osteoarthritis. A common observation post-operatively is radiolucency between the tibial tray wall and the bone. In addition, some patients complain of persistent pain over the proximal tibia antero-medially; this may be related to elevated bone strains in the tibia. Currently, there is no intentionally made mechanical bond between the vertical wall of an Oxford UKR and the adjacent bone; whether one exists or not will influence the load transmission in the proximal tibia and may affect the elevated tibia strain. The aim of this study was to investigate how introducing a mechanical tie between the tibial tray wall and the adjacent bone might alter the load carried into the tibia for both cemented and cementless UKRs. Strain energy density in the region of bone adjacent to the tray wall was considerably increased when a mechanical tie was introduced; this has the potential of reducing the likelihood of a radiolucency occurring in that region. Moreover, a mechanical tie had the effect of reducing proximal tibia strain, which may decrease the incidence of pain following implantation with a UKR.

  4. PURIFIED WASTE FCC CATALYST AS A CEMENT REPLACEMENT MATERIAL

    Directory of Open Access Journals (Sweden)

    Danute Vaiciukyniene

    2015-06-01

    Full Text Available Zeolites are commonly used in the fluid catalytic cracking process. Zeolite polluted with oil products and became waste after some time used. The quantity of this waste inevitably rises by expanding rapidly oil industry. The composition of these catalysts depends on the manufacturer and on the process that is going to be used. The main factors retarding hydration process of cement systems and modifying them strength are organic compounds impurities in the waste FCC catalyst. The present paper shows the results of using purified waste FCC catalyst (pFCC from Lithuania oil refinery, as Portland cement replacement material. For this purpose, the purification of waste FCC catalyst (FCC samples was treated with hydrogen peroxide. Hydrogen peroxide (H2O2 is one of the most powerful oxidizers known. By acting of waste with H2O2 it can eliminate the aforementioned waste deficiency, and the obtained product becomes one of the most promising ingredients, in new advanced building materials. Hardened cement paste samples with FCC or pFCC were formed. It was observed that the pFCC blended cements developed higher strength, after 28 days, compared to the samples with FCC or reference samples. Typical content of Portland cement substituting does not exceed 30 % of mass of Portland cement in samples. Reducing the consumption of Portland cement with utilizing waste materials is preferred for reasons of environmental protection.

  5. Bone graft materials in fixation of orthopaedic implants in sheep.

    Science.gov (United States)

    Babiker, Hassan

    2013-07-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking skeletal bones. The osteoconductive properties of the composite might be improved by adding bone marrow aspirate (BMA), which can be harvested during surgery. Other alternatives to bone graft are demineralised bone matrix (DBM) and human cancellous bone (CB). DBM is prepared by acid extraction of human bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA/Collagen composite alone and in combination with BMA on the early fixation of porous coated titanium implants. In addition, the study compares also the effect of autograft with the gold standard allograft. By using a sheep model, the implants were inserted in the trabecular bone of femoral condyles. The test biomaterials were placed in a well defined peri-implant gap. After the observation period, the bone-implant specimens were harvested and evaluated mechanically by a destructive push

  6. Microstructure, cytotoxicity and corrosion of powder-metallurgical iron alloys for biodegradable bone replacement materials

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Bernd; Sievers, Birte; Utzschneider, Sandra; Mueller, Peter; Jansson, Volkmar [Department of Orthopedic Surgery, Ludwig-Maximilians-University of Munich, Marchioninistrasse 15, 81377 Muenchen (Germany); Roessler, Sophie; Nies, Berthold [InnoTERE GmbH, Tatzberg 47, 01307 Dresden (Germany); Stephani, Guenter; Kieback, Bernd [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany); Quadbeck, Peter, E-mail: peter.quadbeck@ifam-dd.fraunhofer.de [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany)

    2011-12-15

    Up to now biodegradable bone implants with the ability of bearing high loads for the temporary replacement of bones or as osteosynthesis material are not available. Iron and iron based alloys have been identified as appropriate materials, since they combine high strength at medium corrosion rates. Thus, the aim of the present study is the development of a degradable iron based alloy with the perspective of using them as matrix material of cellular structures with biomechanical tailored properties. A powder metallurgical approach has been used to manufacture Fe-C, Fe-0.6P, Fe-1.6P, Fe-B and Fe-Ag samples, which have been tested with respect to their microstructure, their cytotoxicity, and their degradation rate. In order to determine the cytotoxicity of the material a monolayer culture of fibroblast and a perfusion chamber system has been chosen, which was recommended by the ISO 10993-5:1999 for biological testing of medical devices. It has been found, that in particular phosphorus features beneficial properties, since density and thus the strength of the material are increased. No corrosion inhibiting effects of phosphorus on the degradation rate have been found.

  7. Predictors of clinical outcome in total hip and knee replacement : a methodological appraisal of implants and patient factors

    NARCIS (Netherlands)

    Keurentjes, Johan Christiaan

    2014-01-01

    In this thesis, we studied both implants and patient and surgeon factors as predictors of clinical outcome after total hip and knee replacement. Additionally, we studied a number of methodological aspects of orthopaedic research, such as competing risks in estimating the probability of revision

  8. A prospective, randomised trial of transapical transcatheter aortic valve implantation vs. surgical aortic valve replacement in operable elderly patients with aortic stenosis

    DEFF Research Database (Denmark)

    Nielsen, Hans Henrik Møller; Klaaborg, Kaj E; Nissen, Henrik

    2012-01-01

    In a prospective randomised trial we aimed to compare transapical transcatheter aortic valve implantation (a-TAVI) with surgical aortic valve replacement (SAVR) in operable elderly patients.......In a prospective randomised trial we aimed to compare transapical transcatheter aortic valve implantation (a-TAVI) with surgical aortic valve replacement (SAVR) in operable elderly patients....

  9. Accuracy of different impression materials in parallel and nonparallel implants

    Directory of Open Access Journals (Sweden)

    Mahroo Vojdani

    2015-01-01

    Conclusion: Within the limitations of this study, in parallel conditions, the type of impression material cannot affect the accuracy of the implant impressions; however, in nonparallel conditions, polyvinyl siloxane is shown to be a better choice, followed by vinyl siloxanether and polyether respectively.

  10. Clinical Application of Ophthalmic Implant Materials and Biocompatibility

    Directory of Open Access Journals (Sweden)

    Ke Feng

    2017-01-01

    Full Text Available A biomedical material, which is a material to diagnose, treat and repair a living body or to replace its damaged tissue and organ, or to enhance its functions, is one of effective tools that human uses to fight against diseases.

  11. Tissue reactions after intraosseous implantation of three retrofilling materials.

    Science.gov (United States)

    Morinaga, Kazuki; Nakagawa, Kan-Ichi; Carr, Gary B

    2003-02-01

    Bone tissue reactions to EBA, IRM, and cyanoacrylate cement (Base Liner) were studied in the rat mandible using an intraosseous implant method. Osseous cavities (1.4 mm in diameter) were surgically created in the mandibles, and materials were implanted in 60 male Wistar rats. Each specimen was evaluated histologically after 4 and 8 weeks. The development of fibrous connective tissue in direct apposition to the material was observed in the EBA and IRM groups at 4 weeks. A slight degree of macrophage infiltration was seen in the EBA group. After the 8-week observation period, IRM and EBA were frequently separated from the bone cavity by a fibrous connective tissue layer (p IRM materials tested and seems to be a biocompatible material.

  12. Titanium: the mystery metal of implant dentistry. Dental materials aspects.

    Science.gov (United States)

    Parr, G R; Gardner, L K; Toth, R W

    1985-09-01

    A number of important points concerning titanium and its alloys have been discussed. They are summarized as follows. Ti and its alloys, particularly the alpha-beta alloys, possess mechanical properties that make them ideal implant materials. Ti and its alloys oxidize readily in air. This surface oxide is extremely stable in the physiologic environment of the body. The stability and inertness of this surface oxide layer acts to protect Ti from corrosive breakdown when used in the body. The elimination of surface irregularities and contaminants is important when preparing a metal for implantation. Titanium can be coupled with equally passive metals in the body without causing galvanic corrosion.

  13. Material de suturas en periodoncia e implantes.

    OpenAIRE

    Canales, Johnny; Facultad de Estomatología. Universidad Peruana Cayetano Heredia. Lima.; Espinoza-Montes, Carlos; Facultad de Estomatología. Universidad Peruana Cayetano Heredia. Lima.; Alarcón-Palacios, Marco; Facultad de Estomatología. Universidad Peruana Cayetano Heredia. Lima,

    2014-01-01

    Entre los biomateriales más usados en Periodoncia e Implantología Oral las suturas constituyen parte fundamental del éxito de los tratamientos quirúrgicos. En la extensa revisión de la literatura disponible no hay una idea clara del material ideal de sutura  para la cirugía periodontal e implantológica. A pesar de varias evaluaciones comparativas que se han publicado existen controversias de las propiedades, la biodegradabilidad y el rendimiento de los materiales de sutura. El presente artícu...

  14. Implant-Supported Single Crowns Replacing Congenitally Missing Maxillary Lateral Incisors: A 5-Year Follow-Up.

    Science.gov (United States)

    Branzén, Marie; Eliasson, Alf; Arnrup, Kristina; Bazargani, Farhan

    2015-12-01

    Knowledge of the long-term survival of single implants in cases of congenitally missing lateral incisors in the maxilla is limited. This retrospective study aimed to evaluate the 5-year survival of implants and implant-supported crowns (ISCs) and to assess the functional and aesthetic outcomes from the professional and patient perspectives. From a total of 46 patients with congenitally missing upper lateral incisors, 36 patients treated with 54 Brånemark® (Nobel Biocare AB, Göteborg, Sweden) implants and ISCs participated in the study. A clinical examination, California Dental Association (CDA) evaluation, and patient questionnaire were used to rate and compare the objective and subjective evaluations of the ISCs. The survival of implants and ISCs was 100%. The CDA ratings were satisfactory for all ISCs, with 70% being rated excellent. The patient rating was also high for the overall satisfaction item, with 21 being completely satisfied and 14 fairly satisfied. However, 12 patients wished for the replacement of their ISCs. Logistic regression analysis indicated that a less optimal embrasure fill was the most discriminating factor though not statistically significant (p = .082). One-third of the patients wished for the replacement of their ISCs. Soft tissue adaptation seems to be an important factor for overall satisfaction. © 2014 Wiley Periodicals, Inc.

  15. The effect of placing a bone replacement graft in the gap at immediately placed implants: a randomized clinical trial.

    Science.gov (United States)

    Sanz, Mariano; Lindhe, Jan; Alcaraz, Jaime; Sanz-Sanchez, Ignacio; Cecchinato, Denis

    2017-08-01

    To assess the added value of using a bone replacement graft in combination with immediate implants in reducing the bone dimensional changes occurring in the residual ridge. Randomized parallel controlled clinical trial to study the efficacy of grafting with demineralized bovine bone mineral with 10% collagen (DBBM-C) in the gap between the implant surface and the inner bone walls when the implants were immediately placed in the anterior maxilla. The changes between implant placement and 16 weeks later in the horizontal and vertical crestal bone changes in relation to the implant were evaluated through direct bone measurements using a periodontal probe. Mean changes were compared between the experimental and control sites using parametric statistics. A total of 86 implant sites in 86 subjects were included in the analysis (43 in the test group and 43 in the control group). The horizontal crest dimension underwent marked changes during healing mainly at the buccal aspect of the alveolar crest where this reduction amounted to 1.1 (29%) in the test group and 1.6 mm (38%) in the control group, being these statistically significant (P = 0.02). This outcome was even more pronounced at sites in the anterior maxilla and with thinner buccal bone plates. In conclusion, the results from this clinical trial demonstrated that placing a DBBM-C bone replacement graft significantly reduced the horizontal bone resorptive changes occurring in the buccal bone after the immediate implantation in fresh extraction sockets. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Biocompatibility of implantable materials: An oxidative stress viewpoint.

    Science.gov (United States)

    Mouthuy, Pierre-Alexis; Snelling, Sarah J B; Dakin, Stephanie G; Milković, Lidija; Gašparović, Ana Čipak; Carr, Andrew J; Žarković, Neven

    2016-12-01

    Oxidative stress occurs when the production of oxidants surpasses the antioxidant capacity in living cells. Oxidative stress is implicated in a number of pathological conditions such as cardiovascular and neurodegenerative diseases but it also has crucial roles in the regulation of cellular activities. Over the last few decades, many studies have identified significant connections between oxidative stress, inflammation and healing. In particular, increasing evidence indicates that the production of oxidants and the cellular response to oxidative stress are intricately connected to the fate of implanted biomaterials. This review article provides an overview of the major mechanisms underlying the link between oxidative stress and the biocompatibility of biomaterials. ROS, RNS and lipid peroxidation products act as chemo-attractants, signalling molecules and agents of degradation during the inflammation and healing phases. As chemo-attractants and signalling molecules, they contribute to the recruitment and activation of inflammatory and healing cells, which in turn produce more oxidants. As agents of degradation, they contribute to the maturation of the extracellular matrix at the healing site and to the degradation of the implanted material. Oxidative stress is itself influenced by the material properties, such as by their composition, their surface properties and their degradation products. Because both cells and materials produce and react with oxidants, oxidative stress may be the most direct route mediating the communication between cells and materials. Improved understanding of the oxidative stress mechanisms following biomaterial implantation may therefore help the development of new biomaterials with enhanced biocompatibility.

  17. Single-tooth replacement by osseointegrated Astra Tech dental implants: a 2-year report

    DEFF Research Database (Denmark)

    Karlsson, U; Gotfredsen, K; Olsson, C

    1998-01-01

    This study presents the outcome of single-tooth restorations supported by Astra Tech single-tooth implants followed for 2 years. Forty-seven implants were placed in the same number of patients. Forty-three patients attended the second recall visit, and none of the evaluated implants have been...

  18. 21 CFR 878.3500 - Polytetrafluoroethylene with carbon fibers composite implant material.

    Science.gov (United States)

    2010-04-01

    ... composite implant material. 878.3500 Section 878.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION... Prosthetic Devices § 878.3500 Polytetrafluoroethylene with carbon fibers composite implant material. (a) Identification. A polytetrafluoroethylene with carbon fibers composite implant material is a porous...

  19. The Use of Ion Implantation for Materials Processing.

    Science.gov (United States)

    1980-10-06

    IPreEEhhh I l...fflllffllff NRL Memorandum Report 4341 TheUseofIon Implantation for Materials Processing Semana Progres Report for the Period 1 Oct. 1979...beam current. The temperature was judged by observing of results to be expected from such a Gaussian distribution the color of the samples through a...light multiply tion." ion channeling,’ ’ Coates-Kikuchi lines,’ physical ap- reflected between the front surface and the interface between pearance ( color

  20. Titanium Nitride and Nitrogen Ion Implanted Coated Dental Materials

    Directory of Open Access Journals (Sweden)

    David W. Berzins

    2012-07-01

    Full Text Available Titanium nitride and/or nitrogen ion implanted coated dental materials have been investigated since the mid-1980s and considered in various applications in dentistry such as implants, abutments, orthodontic wires, endodontic files, periodontal/oral hygiene instruments, and casting alloys for fixed restorations. Multiple methodologies have been employed to create the coatings, but detailed structural analysis of the coatings is generally lacking in the dental literature. Depending on application, the purpose of the coating is to provide increased surface hardness, abrasion/wear resistance, esthetics, and corrosion resistance, lower friction, as well as greater beneficial interaction with adjacent biological and material substrates. While many studies have reported on the achievement of these properties, a consensus is not always clear. Additionally, few studies have been conducted to assess the efficacy of the coatings in a clinical setting. Overall, titanium nitride and/or nitrogen ion implanted coated dental materials potentially offer advantages over uncoated counterparts, but more investigation is needed to document the structure of the coatings and their clinical effectiveness.

  1. Raman microprobe measurements of stress in ion implanted materials

    Energy Technology Data Exchange (ETDEWEB)

    Nugent, K.W.; Prawer, S.; Weiser, P.S.; Dooley, S.P. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Raman microprobe measurements of ion implanted diamond and silicon have shown significant shifts in the Raman line due to stresses in the materials. The Raman line shifts to higher energy if the stress is compressive and to lower energy for tensile stress{sup 1}. The silicon sample was implanted in a 60 {mu}m square with 2.56 x 10{sup 17} ions per square centimeter of 2 MeV Helium. This led to the formation of raised squares with the top 370mm above the original surface. In Raman studies of silicon using visible light, the depth of penetration of the laser beam into the sample is much less than one micron. It was found that the Raman line is due to the silicon overlying the damage region. The diamond sample was implanted with 2 x 10{sup 15} ions per square centimeter of 2.8 MeV carbon. It was concluded that the Raman spectrum could provide information concerning both the magnitude and the direction of stress in an ion implanted sample. It was possible in some cases to determine whether the stress direction is parallel or perpendicular to the sample surface. 1 refs., 2 figs.

  2. Alternative materials to improve total hip replacement tribology.

    Science.gov (United States)

    Santavirta, Seppo; Böhler, Max; Harris, William H; Konttinen, Yrjö T; Lappalainen, Reijo; Muratoglu, Orhun; Rieker, Claude; Salzer, Martin

    2003-08-01

    An improvement in tribology of bearing surfaces is an effective means of increasing the longevity of total hip replacement (THR). Currently, 3 approaches are available to achieve this aim: first, use of highly cross-linked UHMWPE; second, aluminum oxide ceramic bearings, and third, metal-on-metal bearings. Cross-linking reduces the wear resistance of UHMWPE markedly without impairment of other significant properties of the material. Simulator studies and some clinical long-term (10-22 years) follow-up surveys suggest an almost immeasurable wear of the highly cross-linked UHMWPE-based acetabular components during an expected clinical life span. Bioinert alumina ceramic (aluminum oxide) was introduced 3 decades ago for THR-bearing surfaces to improve performance and longevity. Alumina ceramic is entirely biostable and bioinert and has good mechanical properties. For correctly positioned alumina-on-alumina bearings, the annual linear wear rate has been reported to be 3.9 microm. Alumina heads have been successfully used in combination with polyethylene sockets, but as regards wear, the best results have been obtained with alumina-on-alumina bearings. In ceramic THR bearings, precise manufacture and contact surface geometry, including optimal clearance, are most important. For the currently available products, the component fracture risk is almost nonexistent (less than 1 per 1000). Metal-on-metal bearings were used in the early stage of THR surgery, although not all old designs were successful. More recent analyses of the early series have shown the advantages of metal-on-metal to be better and have led to a renaissance of this articulation. Initially, stainless steel was used because it was easy to manufacture and polish. Current metal-on-metal bearings are based on cobalt-chromium-molybdenum alloys with varying carbon contents. Such bearings are self-polishing. Linear wear rates remain at the level of a few microm a year. An improvement in technology has increased

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

    Science.gov (United States)

    Rubino, Caroline

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

  4. Influence of implant position on clinical crown length and peri-implant soft tissue dimensions at implant-supported single crowns replacing maxillary central incisors

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana

    2013-01-01

    as controls. Paired sample t-testand Pearson´s correlation analysis were used to analyze implant position, dimension of crownand papilla fill.Cohen’s ¿ andSpearman correlation were used to validate the PIS.The implant-supported crown was statistically longer than the contra-lateral tooth......The aims of the present study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors, and to validate the papilla index score (PIS). Twenty-five patients, who had lost one......, and there was significant correlation between the oro-facial position of the implant and the crown length difference (r=.607, p=.001). The distalpapilla was significantly shorter than the mesialpapilla at implant-supported crowns (p

  5. Mg-Zr-Sr alloys as biodegradable implant materials.

    Science.gov (United States)

    Li, Yuncang; Wen, Cuie; Mushahary, Dolly; Sravanthi, Ragamouni; Harishankar, Nemani; Pande, Gopal; Hodgson, Peter

    2012-08-01

    Novel Mg-Zr-Sr alloys have recently been developed for use as biodegradable implant materials. The Mg-Zr-Sr alloys were prepared by diluting Mg-Zr and Mg-Sr master alloys with pure Mg. The impact of Zr and Sr on the mechanical and biological properties has been thoroughly examined. The microstructures and mechanical properties of the alloys were characterized using optical microscopy, X-ray diffraction and compressive tests. The corrosion resistance was evaluated by electrochemical analysis and hydrogen evolution measurement. The in vitro biocompatibility was assessed using osteoblast-like SaOS2 cells and MTS and haemolysis tests. In vivo bone formation and biodegradability were studied in a rabbit model. The results indicated that both Zr and Sr are excellent candidates for Mg alloying elements in manufacturing biodegradable Mg alloy implants. Zr addition refined the grain size, improved the ductility, smoothed the grain boundaries and enhanced the corrosion resistance of Mg alloys. Sr addition led to an increase in compressive strength, better in vitro biocompatibility, and significantly higher bone formation in vivo. This study demonstrated that Mg-xZr-ySr alloys with x and y ≤5 wt.% would make excellent biodegradable implant materials for load-bearing applications. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. Functional tooth restoration by next-generation bio-hybrid implant as a bio-hybrid artificial organ replacement therapy.

    Science.gov (United States)

    Oshima, Masamitsu; Inoue, Kaoru; Nakajima, Kei; Tachikawa, Tetsuhiko; Yamazaki, Hiromichi; Isobe, Tomohide; Sugawara, Ayaka; Ogawa, Miho; Tanaka, Chie; Saito, Masahiro; Kasugai, Shohei; Takano-Yamamoto, Teruko; Inoue, Takashi; Tezuka, Katsunari; Kuboki, Takuo; Yamaguchi, Akira; Tsuji, Takashi

    2014-01-01

    Bio-hybrid artificial organs are an attractive concept to restore organ function through precise biological cooperation with surrounding tissues in vivo. However, in bio-hybrid artificial organs, an artificial organ with fibrous connective tissues, including muscles, tendons and ligaments, has not been developed. Here, we have enveloped with embryonic dental follicle tissue around a HA-coated dental implant, and transplanted into the lower first molar region of a murine tooth-loss model. We successfully developed a novel fibrous connected tooth implant using a HA-coated dental implant and dental follicle stem cells as a bio-hybrid organ. This bio-hybrid implant restored physiological functions, including bone remodelling, regeneration of severe bone-defect and responsiveness to noxious stimuli, through regeneration with periodontal tissues, such as periodontal ligament and cementum. Thus, this study represents the potential for a next-generation bio-hybrid implant for tooth loss as a future bio-hybrid artificial organ replacement therapy.

  7. A critical review of dental implant materials with an emphasis on titanium versus zirconia

    NARCIS (Netherlands)

    Osman, R.B.; Swain, M.V.

    2015-01-01

    The goal of the current publication is to provide a comprehensive literature review on the topic of dental implant materials. The following paper focuses on conventional titanium implants and more recently introduced and increasingly popular zirconia implants. Major subtopics include the material sc

  8. Novel ceramic bone replacement material CeraBall seeded with human mesenchymal stem cells.

    NARCIS (Netherlands)

    Douglas, T.E.L.; Liu, Q.; Humpe, A.; Wiltfang, J.; Sivananthan, S.; Warnke, P.H.

    2010-01-01

    OBJECTIVES: Hydroxyapatite (HA) and tricalcium phosphate (TCP) are two very common ceramic materials for bone replacement. A recently developed material for bone replacement is CeraBall, which is a mixed HA-TCP scaffold available as porous spherical scaffolds of diameter 4 and 6 mm. Before their use

  9. Influence of implant position on clinical crown length and peri-implant soft tissue dimensions at implant-supported single crowns replacing maxillary central incisors

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana

    2013-01-01

    The aims of the present study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors, and to validate the papilla index score (PIS). Twenty-five patients, who had lost one of ...

  10. Contribution of loading conditions and material properties to stress shielding near the tibial component of total knee replacements.

    Science.gov (United States)

    Au, Anthony G; James Raso, V; Liggins, A B; Amirfazli, A

    2007-01-01

    This communication reports important preliminary results of a parametric analysis into the stress shielding effects of loading conditions and material properties of a total knee replacement (TKR) prosthesis. A previously developed finite element (FE) model of the proximal tibia that incorporated orthotropic and heterogeneous bone properties was used. Tibiofemoral joint compression and soft tissue (ligament and muscle) forces were also included to better represent the loading condition in the tibia. Stress shielding effects were studied for a prosthesis similar to a commercially available model. Results from the model show that the hypothesis of relatively higher Young's modulus of implant compared to bone as the primary cause of stress shielding is not sufficiently descriptive. Loading conditions as a result of altered bone or implant condylar surface geometry, load placement on the condylar surface, and load pattern created by the TKR are at least as important or, in some cases, more important factors in observed stress shielding immediately post-operation. This finding can be used to focus new implant design on altered loading conditions as well as material selection.

  11. Materials analyses and electrochemical impedance of implantable metal electrodes.

    Science.gov (United States)

    Howlader, Matiar M R; Ul Alam, Arif; Sharma, Rahul P; Deen, M Jamal

    2015-04-21

    Implantable electrodes with high flexibility, high mechanical fixation and low electrochemical impedance are desirable for neuromuscular activation because they provide safe, effective and stable stimulation. In this paper, we report on detailed materials and electrical analyses of three metal implantable electrodes - gold (Au), platinum (Pt) and titanium (Ti) - using X-ray photoelectron spectroscopy (XPS), scanning acoustic microscopy, drop shape analysis and electrochemical impedance spectroscopy. We investigated the cause of changes in electrochemical impedance of long-term immersed Au, Pt and Ti electrodes on liquid crystal polymers (LCPs) in phosphate buffered saline (PBS). We analyzed the surface wettability, surface and interface defects and the elemental depth profile of the electrode-adhesion layers on the LCP. The impedance of the electrodes decreased at lower frequencies, but increased at higher frequencies compared with that of the short-term immersion. The increase of impedances was influenced by the oxidation of the electrode/adhesion-layers that affected the double layer capacitance behavior of the electrode/PBS. The oxidation of the adhesion layer for all the electrodes was confirmed by XPS. Alkali ions (sodium) were adsorbed on the Au and Pt surfaces, but diffused into the Ti electrode and LCPs. The Pt electrode showed a higher sensitivity to surface and interface defects than that of Ti and Au electrodes. These findings may be useful when designing electrodes for long-term implantable devices.

  12. The Relationship between Biofilm and Physical-Chemical Properties of Implant Abutment Materials for Successful Dental Implants.

    Science.gov (United States)

    de Avila, Erica Dorigatti; de Molon, Rafael Scaf; Vergani, Carlos Eduardo; de Assis Mollo, Francisco; Salih, Vehid

    2014-05-07

    The aim of this review was to investigate the relationship between biofilm and peri-implant disease, with an emphasis on the types of implant abutment surfaces. Individuals with periodontal disease typically have a large amount of pathogenic microorganisms in the periodontal pocket. If the individuals lose their teeth, these microorganisms remain viable inside the mouth and can directly influence peri-implant microbiota. Metal implants offer a suitable solution, but similarly, these remaining bacteria can adhere on abutment implant surfaces, induce peri-implantitis causing potential destruction of the alveolar bone near to the implant threads and cause the subsequent loss of the implant. Studies have demonstrated differences in biofilm formation on dental materials and these variations can be associated with both physical and chemical characteristics of the surfaces. In the case of partially edentulous patients affected by periodontal disease, the ideal type of implant abutments utilized should be one that adheres the least or negligible amounts of periodontopathogenic bacteria. Therefore, it is of clinically relevance to know how the bacteria behave on different types of surfaces in order to develop new materials and/or new types of treatment surfaces, which will reduce or inhibit adhesion of pathogenic microorganisms, and, thus, restrict the use of the abutments with indication propensity for bacterial adhesion.

  13. The Relationship between Biofilm and Physical-Chemical Properties of Implant Abutment Materials for Successful Dental Implants

    Directory of Open Access Journals (Sweden)

    Erica Dorigatti de Avila

    2014-05-01

    Full Text Available The aim of this review was to investigate the relationship between biofilm and peri-implant disease, with an emphasis on the types of implant abutment surfaces. Individuals with periodontal disease typically have a large amount of pathogenic microorganisms in the periodontal pocket. If the individuals lose their teeth, these microorganisms remain viable inside the mouth and can directly influence peri-implant microbiota. Metal implants offer a suitable solution, but similarly, these remaining bacteria can adhere on abutment implant surfaces, induce peri-implantitis causing potential destruction of the alveolar bone near to the implant threads and cause the subsequent loss of the implant. Studies have demonstrated differences in biofilm formation on dental materials and these variations can be associated with both physical and chemical characteristics of the surfaces. In the case of partially edentulous patients affected by periodontal disease, the ideal type of implant abutments utilized should be one that adheres the least or negligible amounts of periodontopathogenic bacteria. Therefore, it is of clinically relevance to know how the bacteria behave on different types of surfaces in order to develop new materials and/or new types of treatment surfaces, which will reduce or inhibit adhesion of pathogenic microorganisms, and, thus, restrict the use of the abutments with indication propensity for bacterial adhesion.

  14. Biofunctionalization of materials for implants using engineered peptides.

    Science.gov (United States)

    Khatayevich, Dmitriy; Gungormus, Mustafa; Yazici, Hilal; So, Christopher; Cetinel, Sibel; Ma, Hong; Jen, Alex; Tamerler, Candan; Sarikaya, Mehmet

    2010-12-01

    Uncontrolled interactions between synthetic materials and human tissues are a major concern for implants and tissue engineering. The most successful approaches to circumvent this issue involve the modification of the implant or scaffold surfaces with various functional molecules, such as anti-fouling polymers or cell growth factors. To date, such techniques have relied on surface immobilization methods that are often applicable only to a limited range of materials and require the presence of specific functional groups, synthetic pathways or biologically hostile environments. In this study we have used peptide motifs that have been selected to bind to gold, platinum, glass and titanium to modify surfaces with poly(ethylene glycol) anti-fouling polymer and the integrin-binding RGD sequence. The peptides have several advantages over conventional molecular immobilization techniques; they require no biologically hostile environments to bind, are specific to their substrates and could be adapted to carry various active entities. We successfully imparted cell-resistant properties to gold and platinum surfaces using gold- and platinum-binding peptides, respectively, in conjunction with PEG. We also induced a several-fold increase in the number and spreading of fibroblast cells on glass and titanium surfaces using quartz and titanium-binding peptides in conjunction with the integrin ligand RGD. The results presented here indicate that control over the extent of cell-material interactions can be achieved by relatively simple and biocompatible surface modification procedures using inorganic binding peptides as linker molecules.

  15. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    . The superficial part was used for mechanical testing and micro-CT scanning, and the profound part for histomorphometry. Push-out tests were performed on an 858 Bionix MTS hydraulic materials testing machine (MTS Systems Corporation, USA). Shear mechanical properties between implant and newly generated bone were......: No significant differences regarding failure energy (kJ/m2, p=0.44) or ultimate shear strength (MPa, p=0.17) could be seen. Shear stiffness (MPa) was significantly higher for the allograft group (p=0.04). Group 2: No significant differences regarding failure energy (p=0.11) or shear stiffness (p=0.52) could...

  16. Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release?

    Science.gov (United States)

    Medley, John B

    2016-05-01

    One of the most important mandates of physical joint simulators is to provide test results that allow the implant manufacturer to anticipate and perhaps avoid clinical wear problems with their new products. This is best done before market release. This study gives four steps to follow in conducting such wear simulator testing. Two major examples involving hip wear simulators are discussed in which attempts had been made to predict clinical wear performance prior to market release. The second one, involving the DePuy ASR implant systems, is chosen for more extensive treatment by making it an illustrative example to explore whether wear simulator testing can anticipate clinical wear problems. It is concluded that hip wear simulator testing did provide data in the academic literature that indicated some risk of clinical wear problems prior to market release of the ASR implant systems. This supports the idea that physical joint simulators have an important role in the pre-market testing of new joint replacement implants.

  17. Materials characterization studies on LANA75/85 materials for replacement beds

    Energy Technology Data Exchange (ETDEWEB)

    Shanahan, Kirk L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-30

    During FY15 and FY16, a purchase order (PO) was placed with Japan Metals and Chemicals, USA after an open bidding procurement process for 282 kg of LaNi4.25Al0.75 and 226 kg. of LaNi4.15Al0.85. These materials were to be used in Tritium Facility replacement beds for existing beds that have reached the end of their useful life. As part of the PO, a 100 g. sample of each material was delivered to the SRNL Hydrogen Processing Group for characterization studies as is typically done for all newly acquired hydride materials. The PO actually employed a “trust but verify” approach where JMCUSA was allowed to ship materials it felt met specifications without SRS confirmation, as long as the data used to do so was delivered to SRS as part of the PO documentation package. Subsequent SRNL analysis revealed that the material met all specifications and was of very high quality. This report documents those findings.

  18. When operable patients become inoperable: conversion of a surgical aortic valve replacement into transcatheter aortic valve implantation

    DEFF Research Database (Denmark)

    Olsen, Lene Kjaer; Arendrup, Henrik; Engstrøm, Thomas

    2009-01-01

    Transcatheter aortic valve implantation (TAVI) is a relatively new treatment option for inoperable patients with severe aortic stenosis (AS). This case describes how a planned conventional surgical aortic valve replacement (AVR) on a 73-year-old woman was successfully converted to a TAVI procedure....... On extracorporal circulation it was reconized that the aortic annulus, the coronary ostiae and the proximal part of the ascending aorta were severely calcified making valve implantation impossible. Surgical closure without valve substitution was estimated to be associated with a high risk of mortality due......, and the prosthesis was sutured to the ascending aorta. With some manipulation of the prosthesis it was possible to suture the aorta circumferentially around the fully expanded upper part of the prosthesis. Post-procedurally the patient recovered successfully, with improved function capacity, aortic valve area...

  19. Modern materials in fabrication of scaffolds for bone defect replacement

    Science.gov (United States)

    Bazlov, V. A.; Mamuladze, T. Z.; Pavlov, V. V.; Kirilova, I. A.; Sadovoy, M. A.

    2016-08-01

    The article defines the requirements for modern scaffold-forming materials and describes the main advantages and disadvantages of various synthetic materials. Osseointegration of synthetic scaffolds approved for use in medical practice is evaluated. Nylon 618 (certification ISO9001 1093-1-2009) is described as the most promising synthetic material used in medical practice. The authors briefly highlight the issues of individual bone grafting with the use of 3D printing technology. An example of contouring pelvis defect after removal of a giant tumor with the use of 3D models is provided.

  20. Helical rosette nanotubes: a more effective orthopaedic implant material

    Science.gov (United States)

    Chun, Ai Lin; Moralez, Jesus G.; Fenniri, Hicham; Webster, Thomas J.

    2004-04-01

    Due to the nanometric properties of some physiological components of bone, nanomaterials have been proposed as the next generation of improved orthopaedic implant materials. Yet current efforts in the design of orthopaedic materials such as titanium (Ti) are not aimed at tailoring their nanoscale features, which is now believed to be one reason why Ti sometimes fails clinically as a bone implant material. Much effort is thus being dedicated to developing improved bioactive nanometric surfaces and nanomaterials for biospecificity. Helical rosette nanotubes (HRN) are a new class of self-assembled organic nanotubes possessing biologically-inspired nanoscale dimensions. Because of their chemical and structural similarity with naturally-occurring nanostructured constituent components in bone such as collagen and hydroxyapatite, we anticipated that an HRN-coated surface may simulate an environment that bone cells are accustomed to interacting with. The objective of the present in vitro study is therefore to determine the efficacy of HRN as a bone prosthetic material. Results of this study clearly show that both HRN-K1 and HRN-Arg coated Ti displayed enhanced cell adhesion when compared to uncoated Ti. Enhanced cell adhesion was observed even at concentrations as low as 0.005 mg ml-1. These results point towards new possibilities in bone tissue engineering as they serve as a starting point for further mechanistic studies as well as future manipulation of the outer chemistries of HRN to improve the results beyond those presented here. One such effort is the incorporation of peptide sequences on the outer surface of HRN and/or growth factors known to enhance bone functions.

  1. Bio-Root and Implant-Based Restoration as a Tooth Replacement Alternative.

    Science.gov (United States)

    Gao, Z H; Hu, L; Liu, G L; Wei, F L; Liu, Y; Liu, Z H; Fan, Z P; Zhang, C M; Wang, J S; Wang, S L

    2016-06-01

    We previously reported that dental stem cell-mediated bioengineered tooth root (bio-root) regeneration could restore tooth loss in a miniature pig model. As a potential new method for tooth restoration, it is essential to compare this method with the widely used commercial dental implant-based method of tooth restoration. Tooth loss models were created by extracting mandibular incisors from miniature pigs. Allogeneic periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) were isolated and cultured. A PDLSC sheet was prepared by adding 20.0 µg/mL vitamin C to the culture medium; in addition, a hydroxyapatite tricalcium phosphate (HA/TCP)/DPSC graft was fabricated and cultured in a 3-dimensional culture system. A total of 46 bio-root implantations and 9 dental implants were inserted, and crown restorations were performed 6 mo after implantation. Histological, radiological, biomechanical, and elemental analyses were used to evaluate and compare tissue-engineered bio-roots and dental implants to the natural tooth roots. After 6 mo, both computed tomography scans and histological examinations showed that root-like structures and dentin-like tissues had formed. Three months after crown restoration, clinical assessments revealed that tooth function was equivalent in the regenerated bio-root and the dental implant. Biomechanical testing showed that the bio-roots were similar to natural tooth roots in compressive strength, modulus of elasticity, and torsional force; however, these properties were significantly higher in the dental implants. Elemental analysis revealed a higher similarity in elemental composition between bio-roots and natural tooth roots than between bio-roots and dental implants. However, the dental implant success rate was 100% (9 of 9) and the bio-root success rate was only 22% (10 of 46). Taken together, we showed that an allogeneic HA/TCP/DPSC/PDLSC sheet could successfully build a bio-root with structure and function similar to

  2. 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.

  3. Titanium implant insertion into dog alveolar ridges augmented by allogenic material

    DEFF Research Database (Denmark)

    Pinholt, E M; Haanaes, H R; Donath, K

    1994-01-01

    The purpose of this investigation was to evaluate whether titanium endosseous implants would osseointegrate in dog alveolar ridges augmented by allogenic material. In 8 dogs en bloc resection, including 2 pre-molars, was performed bilaterally in the maxilla and the mandible. After a healing period...... of 6 weeks allogenic, demineralized and lyophilized dentin or bone was implanted subperiosteally. Titanium implants were installed 5.5 months later in some of the regions. Light and fluorescence microscopic evaluation revealed fibrous encapsulation of the implanted allogenic material, no osteoinduction...... and only minimal osteoconduction, few multinuclear giant cells and a sparse inflammatory reaction. The titanium implants healed mainly by fibrous encapsulation....

  4. A Critical Review of Dental Implant Materials with an Emphasis on Titanium versus Zirconia

    Directory of Open Access Journals (Sweden)

    Reham B. Osman

    2015-03-01

    Full Text Available The goal of the current publication is to provide a comprehensive literature review on the topic of dental implant materials. The following paper focuses on conventional titanium implants and more recently introduced and increasingly popular zirconia implants. Major subtopics include the material science and the clinical considerations involving both implant materials and the influence of their physical properties on the treatment outcome. Titanium remains the gold standard for the fabrication of oral implants, even though sensitivity does occur, though its clinical relevance is not yet clear. Zirconia implants may prove to be promising in the future; however, further in vitro and well-designed in vivo clinical studies are needed before such a recommendation can be made. Special considerations and technical experience are needed when dealing with zirconia implants to minimize the incidence of mechanical failure.

  5. Bone replacement following dental trauma prior to implant surgery - present status

    NARCIS (Netherlands)

    Hallman, Mats; Mordenfeld, Arne; Strandkvist, Tomas

    2009-01-01

    Dento-alveolar trauma often leads to a need for reconstruction of the alveolar crest before an implant can be placed. Although autogenous bone grafts is considered the 'gold standard', this may be associated with patient morbidity and graft resorption. Consequently, the use of bone substitutes has i

  6. Replacing the valve restoring the flow: Effects of transcatheter aortic valve implantation

    NARCIS (Netherlands)

    Wiegerinck, E.M.A.

    2016-01-01

    When conventional surgery is not an option due to high surgical risk, transcatheter aortic valve implantation (TAVI) is a firmly established alternative and an effective and safe treatment option in this patient population. This thesis focuses on treatment of aortic valve stenosis by TAVI. The aim i

  7. Bone replacement following dental trauma prior to implant surgery - present status

    NARCIS (Netherlands)

    Hallman, Mats; Mordenfeld, Arne; Strandkvist, Tomas

    2009-01-01

    Dento-alveolar trauma often leads to a need for reconstruction of the alveolar crest before an implant can be placed. Although autogenous bone grafts is considered the 'gold standard', this may be associated with patient morbidity and graft resorption. Consequently, the use of bone substitutes has i

  8. Nitrogen ion implantation into various materials using 28 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chang Seouk [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of); School of Mechanical Engineering, Pusan National University, Pusan 609-735 (Korea, Republic of); Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Won, Mi-Sook, E-mail: mswon@kbsi.re.kr [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of); Lee, Seung Wook, E-mail: Seunglee@pusan.ac.kr [School of Mechanical Engineering, Pusan National University, Pusan 609-735 (Korea, Republic of)

    2016-02-15

    The installation of the 28 GHz electron cyclotron resonance ion source (ECRIS) ion implantation beamline was recently completed at the Korea Basic Science Institute. The apparatus contains a beam monitoring system and a sample holder for the ion implantation process. The new implantation system can function as a multipurpose tool since it can implant a variety of ions, ranging hydrogen to uranium, into different materials with precise control and with implantation areas as large as 1–10 mm{sup 2}. The implantation chamber was designed to measure the beam properties with a diagnostic system as well as to perform ion implantation with an in situ system including a mass spectrometer. This advanced implantation system can be employed in novel applications, including the production of a variety of new materials such as metals, polymers, and ceramics and the irradiation testing and fabrication of structural and functional materials to be used in future nuclear fusion reactors. In this investigation, the first nitrogen ion implantation experiments were conducted using the new system. The 28 GHz ECRIS implanted low-energy, multi-charged nitrogen ions into copper, zinc, and cobalt substrates, and the ion implantation depth profiles were obtained. SRIM 2013 code was used to calculate the profiles under identical conditions, and the experimental and simulation results are presented and compared in this report. The depths and ranges of the ion distributions in the experimental and simulation results agree closely and demonstrate that the new system will enable the treatment of various substrates for advanced materials research.

  9. Toxicity of methods of implant material sterilization on corneal endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, G.; Boehnke, Mv.; von Domarus, D.; Draeger, J.

    1985-11-01

    The toxicity of different procedures utilized for the sterilization of intraocular implant material was assessed on the endothelium of organ-cultured porcine corneas. Polymethylmethacrylate lenses sterilized by treatment with sodium hydroxide (NaOH), ethylene oxide, formaldehyde, and gamma radiation were added to a culture medium containing normal porcine corneas. Considering the viability of endothelial cells, appearance of intracellular degenerative vacuoles, and denudation of corneal Descemet's membrane as criterion for the evaluation of toxicity of different methods of sterilization, the NaOH-treated lenses were found to be the least toxic to porcine corneal endothelium. Phase-contrast microscopy and vital staining of the endothelium permitted direct viewing of the endothelium aiding in the assessment of toxicity.

  10. Effects of implant system, impression technique, and impression material on accuracy of the working cast.

    Science.gov (United States)

    Wegner, Kerstin; Weskott, Katharina; Zenginel, Martha; Rehmann, Peter; Wöstmann, Bernd

    2013-01-01

    This in vitro study aimed to identify the effects of the implant system, impression technique, and impression material on the transfer accuracy of implant impressions. The null hypothesis tested was that, in vitro and within the parameters of the experiment, the spatial relationship of a working cast to the placement of implants is not related to (1) the implant system, (2) the impression technique, or (3) the impression material. A steel maxilla was used as a reference model. Six implants of two different implant systems (Standard Plus, Straumann; Semados, Bego) were fixed in the reference model. The target variables were: three-dimensional (3D) shift in all directions, implant axis direction, and rotation. The target variables were assessed using a 3D coordinate measuring machine, and the respective deviations of the plaster models from the nominal values of the reference model were calculated. Two different impression techniques (reposition/pickup) and four impression materials (Aquasil Ultra, Flexitime, Impregum Penta, P2 Magnum 360) were investigated. In all, 80 implant impressions for each implant system were taken. Statistical analysis was performed using multivariate analysis of variance. The implant system significantly influenced the transfer accuracy for most spatial dimensions, including the overall 3D shift and implant axis direction. There was no significant difference between the two implant systems with regard to rotation. Multivariate analysis of variance showed a significant effect on transfer accuracy only for the implant system. Within the limits of the present study, it can be concluded that the transfer accuracy of the intraoral implant position on the working cast is far more dependent on the implant system than on the selection of a specific impression technique or material.

  11. Evaluation of implant-materials as cell carriers for dental stem cells under in vitro conditions

    OpenAIRE

    Gosau, Martin; Viale-Bouroncle, Sandra; Eickhoff, Hannah; Prateeptongkum, Esthera; Reck, Anja; Götz, W.; Klingelhöffer, Christoph; Müller, Steffen; Morsczeck, Christian

    2015-01-01

    Background Dental stem cells in combination with implant materials may become an alternative to autologous bone transplants. For tissue engineering different types of soft and rigid implant materials are available, but little is known about the viability and the osteogenic differentiation of dental stem cells on these different types of materials. According to previous studies we proposed that rigid bone substitute materials are superior to soft materials for dental tissue engineering. Method...

  12. [Hardened anodized aluminum as a replacement material for bracket manufacture].

    Science.gov (United States)

    Fischer-Brandies, H; Bönhoff, M

    1994-12-01

    Attention has been repeatedly drawn to the problem of corrosion and the risk of allergic reaction to nickel resulting from the use of stainless steel brackets. In the search for a suitable alternative, manufacturers have turned to thin coating technology using hardened anodized aluminium. Applying resistance to corrosion and abrasion as the criteria to be met, they have selected aluminium alloy type 6082 as the material of choice. Purpose of this study is to examine the physical suitability of this material. Using the above noted alloy, 60 prototype brackets were made with a hardened anodized surface. They were then subjected to the following 3 stress tests: first an abrasion test using a tooth polishing machine, second, a deformation test using a device designed to simulate torque movement, and, third, a corrosion test. The effects on the brackets resulting from the three types of stress were evaluated by light microscopy. A quantitative analysis of the corrosion test was performed by ICP spectrometry. The control group consisted of conventional stainless steel brackets. The light microscopic analysis revealed no evidence of surface damage or signs of deformation in the prototype brackets. The steel brackets, on the other hand, showed clear signs of wear and corrosion. The quantitative analysis of the corrosion solution revealed metallic ion wear of 1.75 ng x mm-2 x h-1 for the prototypes subjected to abrasion. The steel brackets showed at a factor of around 104.6 metallic ion wear of 183 ng x mm-2 x h-1. In addition to this, no Ni ions were found in the corrosion solution of the prototype brackets.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Bone replacement following dental trauma prior to implant surgery--status.

    Science.gov (United States)

    Hallman, Mats; Mordenfeld, Arne; Strandkvist, Tomas

    2009-02-01

    Dento-alveolar trauma often leads to a need for reconstruction of the alveolar crest before an implant can be placed. Although autogenous bone grafts is considered the 'gold standard', this may be associated with patient morbidity and graft resorption. Consequently, the use of bone substitutes has increased. Today, a substantial number of biomaterials are available on the market, but only a few are well documented. The user should be aware that these biomaterials have different properties: resorbable or non-resorbable, time of resorption and resorption mechanism. The purpose of this review is to describe the function of various bone substitutes and indications for their use in reconstructive implant surgery and to give an overview of the current situation.

  14. Patient and implant survival following joint replacement because of metastatic bone disease

    DEFF Research Database (Denmark)

    Sørensen, Michala S; Gregersen, Kristine G; Grum-Schwensen, Tomas

    2013-01-01

    Patients suffering from a pathological fracture or painful bony lesion because of metastatic bone disease often benefit from a total joint replacement. However, these are large operations in patients who are often weak. We examined the patient survival and complication rates after total joint...

  15. Methods for Implant Acceptance and Wound Healing: Material Selection and Implant Location Modulate Macrophage and Fibroblast Phenotypes.

    Science.gov (United States)

    Boddupalli, Anuraag; Zhu, Lida; Bratlie, Kaitlin M

    2016-10-01

    This review focuses on materials and methods used to induce phenotypic changes in macrophages and fibroblasts. Herein, we give a brief overview on how changes in macrophages and fibroblasts phenotypes are critical biomarkers for identification of implant acceptance, wound healing effectiveness, and are also essential for evaluating the regenerative capabilities of some hybrid strategies that involve the combination of natural and synthetic materials. The different types of cells present during the host response have been extensively studied for evaluating the reaction to different materials and there are varied material approaches towards fabrication of biocompatible substrates. We discuss how natural and synthetic materials have been used to engineer desirable outcomes in lung, heart, liver, skin, and musculoskeletal implants, and how certain properties such as rigidity, surface shape, and porosity play key roles in the progression of the host response. Several fabrication strategies are discussed to control the phenotype of infiltrating macrophages and fibroblasts: decellularization of scaffolds, surface coatings, implant shape, and pore size apart from biochemical signaling pathways that can inhibit or accelerate unfavorable host responses. It is essential to factor all the different design principles and material fabrication criteria for evaluating the choice of implant materials or regenerative therapeutic strategies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Rationale for one stage exchange of infected hip replacement using uncemented implants and antibiotic impregnated bone graft.

    Science.gov (United States)

    Winkler, Heinz

    2009-09-04

    Infection of a total hip replacement (THR) is considered a devastating complication, necessitating its complete removal and thorough debridement of the site. It is undoubted that one stage exchange, if successful, would provide the best benefit both for the patient and the society. Still the fear of re-infection dominates the surgeons decisions and in the majority of cases directs them to multiple stage protocols. However, there is no scientifically based argument for that practice. Successful eradication of infection with two stage procedures is reported to average 80% to 98%. On the other hand a literature review of Jackson and Schmalzried (CORR 2000) summarizing the results of 1,299 infected hip replacements treated with direct exchange (almost exclusively using antibiotic loaded cement), reports of 1,077 (83%) having been successful. The comparable results suggest, that the major factor for a successful outcome with traditional approaches may be found in the quality of surgical debridement and dead space management. Failures in all protocols seem to be caused by small fragments of bacterial colonies remaining after debridement, whereas neither systemic antibiotics nor antibiotic loaded bone cement (PMMA) have been able to improve the situation significantly. Reasons for failure may be found in the limited sensitivity of traditional bacterial culturing and reduced antibiotic susceptibility of involved pathogens, especially considering biofilm formation. Whenever a new prosthesis is implanted into a previously infected site the surgeon must be aware of increased risk of failure, both in single or two stage revisions. Eventual removal therefore should be easy with low risk of additional damage to the bony substance. On the other hand it should also have potential of a good long term result in case of success. Cemented revisions generally show inferior long term results compared to uncemented techniques; the addition of antibiotics to cement reduces its

  17. Rationale for one stage exchange of infected hip replacement using uncemented implants and antibiotic impregnated bone graft

    Directory of Open Access Journals (Sweden)

    Heinz Winkler

    2009-01-01

    Full Text Available Infection of a total hip replacement (THR is considered a devastating complication, necessitating its complete removal and thorough debridement of the site. It is undoubted that one stage exchange, if successful, would provide the best benefit both for the patient and the society. Still the fear of re-infection dominates the surgeons´ decisions and in the majority of cases directs them to multiple stage protocols. However, there is no scientifically based argument for that practice. Successful eradication of infection with two stage procedures is reported to average 80% to 98%. On the other hand a literature review of Jackson and Schmalzried (CORR 2000 summarizing the results of 1,299 infected hip replacements treated with direct exchange (almost exclusively using antibiotic loaded cement, reports of 1,077 (83% having been successful. The comparable results suggest, that the major factor for a successful outcome with traditional approaches may be found in the quality of surgical debridement and dead space management. Failures in all protocols seem to be caused by small fragments of bacterial colonies remaining after debridement, whereas neither systemic antibiotics nor antibiotic loaded bone cement (PMMA have been able to improve the situation significantly. Reasons for failure may be found in the limited sensitivity of traditional bacterial culturing and reduced antibiotic susceptibility of involved pathogens, especially considering biofilm formation. Whenever a new prosthesis is implanted into a previously infected site the surgeon must be aware of increased risk of failure, both in single or two stage revisions. Eventual removal therefore should be easy with low risk of additional damage to the bony substance. On the other hand it should also have potential of a good long term result in case of success. Cemented revisions generally show inferior long term results compared to uncemented techniques; the addition of antibiotics to cement

  18. The past, present and near future of materials for use in biodegradable orthopaedic implants

    Directory of Open Access Journals (Sweden)

    Clara Eugenia Plazas Bonilla

    2011-05-01

    Full Text Available  The aim of bone replacement or fracture treatment methodologies is to induce tissue regeneration respecting anatomy and try to recover functionality. This goal was initially achieved in the 17th century by using animal or human grafts and several medical devices made of natural and synthetic materials are currently used having a whole range of chemical and physical properties. Research in this field continues to seek a solution to the disadvantages usually found when using grafts: immunological reactions, the risk of microbiological contamination, the absence of donors, the need for several surgical interventions and the risk of disease transmission. Basic and applied research must thus be carried out not only in the development of biology and studies about embryonic stem cells but also in the field of new material development. This tendency may be clearly detected by looking at the vast numbers of studies related to using metallic, polymer and ceramic materials and, at present, compound or hybrid materials having potential use in orthopaedic implants. Most of them fulfil conditions regarding biocompatibility and non-toxicity and could be considered when designing biodegradable materials thereby making it feasible to identify a range of research subjects on biomaterials. This paper starts by identifying material development periods and then establishes the advantages and disadvantages of groups which have been considered for bone regeneration and identifies some guidelines which should be taken into account in the field of biodegradable materials in the near future. There is still a long way to go in this subject, especially regarding the field of materials science and technology. 

  19. High density porous polyethylene material (Medpor) as an unwrapped orbital implant

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan-hong; CUI Hong-guang

    2006-01-01

    Objective: To introduce the clinical effect among patients who received an unwrapped orbital implant with high density porous polyethylene material (Medpor) after enucleation or evisceration. Methods: Retrospective analysis of a series of 302 patients with anophthalmia who underwent placement of an unwrapped high density porous polyethylene orbital implant. We compared the patients (n=180) who accepted primary implant placement with those (n=122) who accepted secondary implant placement. Parameters evaluated included: age at time of surgery, date of surgery, sex, implant type and size, surgery type, the surgical procedure and technique performed, and complications. Results: The time of follow-up ranged from 2.0 to 58.0 months (mean 32.5 months). A total of 5 of 302 (1.66%) cases had documented postoperative complications. The following problems were noted after surgery: implant exposure, 3 patients (0.99%); implant removed due to orbital infection, 1 patient (0.34%); ptosis, 1 patient (0.34%). There were no significant complications observed in other 297 cases and all implants showed good orbital motility. The clinical effect of primary implant placement is better than that of secondary placement. Conclusion: High density porous polyethylene material can be used successfully as an unwrapped orbital implant in anopthalmic socket surgery with minimal complications. The material is well tolerated, nonantigenic and has low rate of infection and migration.

  20. Mid-luteal serum progesterone concentrations govern implantation rates for cryopreserved embryo transfers conducted under hormone replacement.

    Science.gov (United States)

    Yovich, John L; Conceicao, Jason L; Stanger, James D; Hinchliffe, Peter M; Keane, Kevin N

    2015-08-01

    This study explores the relevance of mid-luteal serum hormonal concentrations in cryopreserved embryo transfer cycles conducted under hormone replacement therapy (HRT) control and which involved single-embryo transfer (SET) of 529 vitrified blastocysts. Widely ranging mid-luteal oestradiol and progesterone concentrations ensued from the unique HRT regimen. Oestradiol had no influence on clinical pregnancy or live birth rates, but an optimal progesterone range between 70 and 99 nmol/l (P decreased implantation rates. There was no clear interaction between oestradiol and progesterone concentrations but embryo quality grading did show a significant influence on outcomes (P pregnancy and live birth rates, respectively). Multiple comparison analysis showed that the progesterone effect was influential regardless of embryo grading, body mass index or the woman's age, either at vitrification or at cryopreserved embryo transfer. The results support the argument that careful monitoring of serum progesterone concentrations in HRT-cryopreserved embryo transfer is warranted and that further studies should explore pessary adjustments to optimize concentrations for individual women to enhance implantation rates.

  1. Microstructure and mechanical properties of open-cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting.

    Science.gov (United States)

    Murr, L E; Amato, K N; Li, S J; Tian, Y X; Cheng, X Y; Gaytan, S M; Martinez, E; Shindo, P W; Medina, F; Wicker, R B

    2011-10-01

    Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily α-phase acicular platelets while the mesh and foam structures were characterized by α(')-martensite with some residual α. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced ~2 μm in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of relative stiffness versus relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone stiffness. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Are polytetrafluoroethylene (Gore-Tex) implants an alternative material for nasal dorsal augmentation in Asians?

    Science.gov (United States)

    Hong, Joon Pio; Yoon, Ji Young; Choi, Jong Woo

    2010-11-01

    Augmentation rhinoplasty is a relatively common procedure in Korea. Alloplastic materials such as silicone, supramid mesh, Proplast, Mersiline, Medpor, and hydroxyapatite are frequently used for dorsal augmentation. Alloplastic implants have advantages, such as ready availability and no donor-site morbidity, but are associated with higher infection and extrusion rates than are autogenous materials. Although polytetrafluoroethylene (Gore-Tex) implants have recently been introduced, such implants are yet to be established as an alternative for nasal augmentation because of a lack of relevant reports. From March 1998 to March 2007, we operated on 873 nasal dorsum augmentation patients using hard-type Gore-Tex implants. The patients were all of Korean ethnicity. There were 826 female and 47 male patients and aged ranging from 18 to 57 years (mean, 24 y). The Gore-Tex implant thicknesses were 3.1 to 4.9 mm (used in 59% of cases), 2 to 3 mm (8%), or 5 to 6 mm (33%). The Gore-Tex implants were used only for dorsal augmentation, whereas conchal or septal cartilage was used for nasal tip plasty. Of the total of 873 patients, 257 received long-term follow-up (mean follow-up, 34 mo). Apart from 34 patients with revision, no patient reported dissatisfaction, and there were no reports of problems with nasal contour, implant migration, or resorption of the implant material. The overall complication rate was 3.8%. Of the 257 long-term follow-up patients, 34 (13.5%) required revision. Four of these patients involved minor complications that were managed conservatively, whereas 30 patients required implant removal and revision procedures. These 30 cases included irregularity, infection, deviation, unfavorable dorsum height, and apparent implant silhouette, in addition to obvious supratip deformity. A review of the literature revealed that Gore-Tex implants seemed to have a lower implant removal rate than silicone implants. However, the overall complication rates seemed to be

  3. Effect of Hydrogen Implantation on SIMOX SOI Materials

    Institute of Scientific and Technical Information of China (English)

    易万兵; 陈静; 陈猛; 王曦; 邹世昌

    2004-01-01

    Hydrogen ions were implanted into separation by implantation of oxygen (SIMOX) silicon-on-insulator (SOI)wafers near the oxygen-implantation-induced damage peak under different conditions of energy and dose. It was found that the implanted hydrogen ions not only accelerate the diffusion of oxygen atoms from the annealing ambience into the wafer but also cause an outward diffusion of oxygen atoms in the buried oxide (BOX) layer.Thus, greatly broadened buried oxygen-rich (BOR) layers were formed in our experiments, which are 18%-79%broader than the BOX layer of standard SIMOX SOI wafers under the same conditions of oxygen implantation.The mechanism was discussed. A potential low cost method to fabricate SIMOX SOI wafers is proposed.

  4. Do we need hip-ankle radiographs to assess the coronal alignment and implant position after total knee replacement?

    Science.gov (United States)

    Dargel, Jens; Oppermann, Johannes; Eysel, Peer; Penning, Lenhard

    2016-01-01

    Aims and Objectives: Restoration of the coronal alignment of the knee is known to be one of the major criteria of a successful total knee arthroplasty (TKA). It therefore appears to be mandatory to routinely assess the postoperative limb alignment using hip-ankle radiographs and to identify implants that may be at risk of premature failure. However, there is no clear consensus whether weight-bearing hip-ankle radiographs or rather standardized a-p knee-radiographs should be used to assess implant position and coronal alignment after TKA. It is the aim of the present study to investigate if implant position and the mechanical alignment after TKA can reproducibly be assessed using standardized a-p knee-radiographs or rather if weight-bearing hip-ankle radiographs are needed. Materials and Methods: This study was performed on 100 postoperative weight-bearing hip-ankle radiographs after conventional primary TKA. The true mechanical and anatomical femorotibial angle as well as coronal implant position (MPTA, LDFA) was assessed using the MediCAD software, which served as a control. The hip-ankle radiographs were then digitally cropped to 80%, 60% and 40% of the leg-length. In each cropped radiograph, tibial coronal implant position was assessed by referencing against the visible mid-shaft, whereas femoral implant position was referenced against the visible mid-shaft (anatomical axis) or against a surrogate mechanical axis, which was drawn perpendicular to the distal tangent of the femoral component. Each measurement was performed by three independent observers. The difference between the alignment parameters in the hip-ankle radiographs were statistically compared with the cropped radiographs and the inter-observer correlation coefficient (ICC) was calculated for each parameter. Results: The ICC for inter-observer agreement of measurement of the mechanical femorotibial angle was significantly higher in hip-ankle radiographs (.95) when compared with a radiograph cropped

  5. 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.

  6. 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

  7. 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

  8. Bone graft materials in fixation of orthopaedic implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    2013-01-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many...... the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking...... bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA...

  9. Bone Adaptation Around Orthopaedic Implants of Varying Materials

    DEFF Research Database (Denmark)

    Bagge, Mette

    1998-01-01

    The bone adaptation around orthopaedic implants is simulated using a three-dimensional finite element model. The remodeling scheme has its origin in optimization methods, and includes anisotropy and time-dependent loading......The bone adaptation around orthopaedic implants is simulated using a three-dimensional finite element model. The remodeling scheme has its origin in optimization methods, and includes anisotropy and time-dependent loading...

  10. Bone Adaptation Around Orthopaedic Implants of Varying Materials

    DEFF Research Database (Denmark)

    Bagge, Mette

    1998-01-01

    The bone adaptation around orthopaedic implants is simulated using a three-dimensional finite element model. The remodeling scheme has its origin in optimization methods, and includes anisotropy and time-dependent loading......The bone adaptation around orthopaedic implants is simulated using a three-dimensional finite element model. The remodeling scheme has its origin in optimization methods, and includes anisotropy and time-dependent loading...

  11. A comparison of fatigue resistance of three materials for cusp-replacing adhesive restorations.

    NARCIS (Netherlands)

    Kuijs, R.H.; Fennis, W.M.M.; Kreulen, C.M.; Roeters, F.J.M.; Verdonschot, N.J.J.; Creugers, N.H.J.

    2006-01-01

    OBJECTIVES: To investigate the fatigue resistance and failure behaviour of cusp-replacing restorations in premolars using different types of adhesive restorative materials. METHODS: A class 2 cavity was prepared and the buccal cusp was removed in an extracted sound human upper premolar. By using a c

  12. The third generation multi-purpose plasma immersion ion implanter for surface modification of materials

    CERN Document Server

    Tang Bao Yin; Wang Xiao Feng; Gan Kong Yin; Wang Song Yan; Chu, P K; Huang Nian Ning; Sun Hong

    2002-01-01

    The third generation multi-purpose plasma immersion ion implantation (PIII) equipment has been successfully used for research and development of surface modification of biomedical materials, metals and their alloys in the Southwest Jiaotong University. The implanter equipped with intense current, pulsed cathodic arc metal plasma sources which have both strong coating function and gas and metal ion implantation function. Its pulse high voltage power supply can provide big output current. It can acquire very good implantation dose uniformity. The equipment can both perform ion implantation and combine ion implantation with sputtering deposition and coating to form many kinds of synthetic surface modification techniques. The main design principles, features of important components and achievement of research works in recent time have been described

  13. Posterior enlargement of the small annulus during aortic valve replacement versus implantation of a small prosthesis.

    Science.gov (United States)

    Pugliese, P; Bernabei, M; Santi, C; Pasqué, A; Eufrate, S

    1984-07-01

    Twenty-two patients with a small aortic annulus were identified among 196 consecutive patients undergoing aortic valve replacement (AVR). The 11 patients in Group 1 underwent posterior enlargement aortic annuloplasty, and the 11 in Group 2 received a small aortic prosthesis (less than or equal to 21 mm). The two groups were unselected. Core hypothermia, cardioplegia, and local cooling were employed for all operations. Isolated AVR was performed in 3 patients in each group. In Group 1, the mean increase in diameter of the annulus was 4.82 mm, which resulted in a mean area increase of 169.91 mm2 (51.7%). Mean aortic cross-clamp times were 140.4 minutes and 93.5 minutes in Groups 1 and 2, respectively. There were 2 operative deaths in Group 1, and 1 operative and 1 late death in Group 2. Mean follow-up was 26.5 months for Group 1 and 43.4 months for Group 2. No thomboembolic or bleeding episodes have been recorded. Considerations and conclusions are offered from the study of this small series of patients.

  14. Substrate-anchored and degradation-sensitive anti-inflammatory coatings for implant materials

    Science.gov (United States)

    Wu, Duo; Chen, Xingyu; Chen, Tianchan; Ding, Chunmei; Wu, Wei; Li, Jianshu

    2015-06-01

    Implant materials need to be highly biocompatible to avoid inflammation in clinical practice. Although biodegradable polymeric implants can eliminate the need for a second surgical intervention to remove the implant materials, they may produce acidic degradation products in vivo and cause non-bacterial inflammation. Here we show the strategy of “substrate-anchored and degradation-sensitive coatings” for biodegradable implants. Using poly(lactic acid)/hydroxyapatite as an implant material model, we constructed a layer-by-layer coating using pH-sensitive star polymers and dendrimers loaded with an anti-inflammatory drug, which was immobilised through a hydroxyapatite-anchored layer. The multifunctional coating can effectively suppress the local inflammation caused by the degradation of implant materials for at least 8 weeks in vivo. Moreover, the substrate-anchored coating is able to modulate the degradation of the substrate in a more homogeneous manner. The “substrate-anchored and degradation-sensitive coating” strategy therefore exhibits potential for the design of various self-anti-inflammatory biodegradable implant materials.

  15. Simultaneous sinus lift and implantation using platelet-rich fibrin as sole grafting material.

    Science.gov (United States)

    Jeong, Seung-Mi; Lee, Chun-Ui; Son, Jeong-Seog; Oh, Ji-Hyeon; Fang, Yiqin; Choi, Byung-Ho

    2014-09-01

    Recently, several authors have shown that simultaneous sinus lift and implantation using autologous platelet-rich fibrin as the sole filling material is a reliable procedure promoting bone augmentation in the maxillary sinus. The aim of this study was to examine the effect of simultaneous sinus lift and implantation using platelet-rich fibrin as the sole grafting material on bone formation in a canine sinus model. An implant was placed after sinus membrane elevation in the maxillary sinus of six adult female mongrel dogs. The resulting space between the membrane and sinus floor was filled with autologous platelet-rich fibrin retrieved from each dog. The implants were left in place for six months. Bone tissue was seen at the lower part of the implants introduced into the sinus cavity. The height of the newly formed bone around the implants ranged from 0 mm to 4.9 mm (mean; 2.6 ± 2.0 mm) on the buccal side and from 0 mm to 4.2 mm (mean; 1.3 ± 1.8 mm) on the palatal side. The findings from this study suggest that simultaneous sinus lift and implantation using platelet-rich fibrin as sole grafting material is not a predictable and reproducible procedure, especially with respect to the bone formation around the implants in the sinus cavity.

  16. Optimum gradient material for a functionally graded dental implant using metaheuristic algorithms.

    Science.gov (United States)

    Sadollah, Ali; Bahreininejad, Ardeshir

    2011-10-01

    Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature.

  17. Nanostructured titanium-based materials for medical implants: Modeling and development

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Levashov, Evgeny; Valiev, Ruslan Z.

    2014-01-01

    . Computational methods of nanostructure properties simulation and various approaches to the computational, "virtual" testing and numerical optimization of these materials are discussed. Applications of atomistic methods, continuum micromechanics and crystal plasticity as well as analytical models to the analysis...... of the reserves of the improvement of materials for medical implants are demonstrated. Examples of successful development of a nanomaterial-based medical implants are presented. (C) 2014 Elsevier B.V. All rights reserved....

  18. Mechanical and biological properties of human hard tissue replacement implants%人体硬组织替代材料的力学及生物学性能研究

    Institute of Scientific and Technical Information of China (English)

    高素霞; 孟和

    2005-01-01

    feature and biological properties of human hard tissue replacement implants for the indication of the direction in its development.STUDY SOURCES: Time of the search was from January 1998 to July 2004. Search range: 30 types of periodicals from CNKI digital library (Chinese Periodical Full Text database) and Science Direct digital library. Search words were hard tissue replacement implants, artificial bone,artificial root of tooth, bioceramic, and biological coat, etc. Search methods included electronic search and manual search, etc.STUDY SELECTION: Totally 200 corresponding literatures on human hard tissue replacement implants were selected for analysing and summarizing.DATA EXTRACTION: To summarize the corresponding information in the obtained research articles regarding hard tissue replacement implant.DATA SYNTHESIS: To comparatively analyze the mechanical and biological properties of each hard tissue replacement implant as well as their effects in practical application. The existing hard tissue replacement implants including metal materials, macromolecular materials, ceramics and their composite materials have been widely applied in clinics; however, their mechanical and biological properties have not been perfectly combined.CONCLUSION: It is always a key point(key point in researches) in biomedical material academia to find a replacement implant, of which the mechanical and biological properties perfectly suitable for the human hard tissues. The new generation of hard tissue replacement implants established by the application of biomimetic process, nano-technology, composite materisls and tissue engineering could hopefully satisfy the increasingly elevated demand of human beings.

  19. [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.

  20. Hardening of Metallic Materials Using Plasma Immersion Ion Implantation (PIII)

    Science.gov (United States)

    Xu, Yufan; Clark, Mike; Flanagan, Ken; Milhone, Jason; Nonn, Paul; Forest, Cary

    2016-10-01

    A new approach of Plasma Immersion Ion Implantation (PIII) has been developed with the Plasma Couette Experiment Upgrade (PCX-U). The new approach efficiently reduces the duty cycle under the same average power for PIII. The experiment uses a Nitrogen plasma at a relatively high density of 1010 1011 cm-3 with ion temperatures of working cycle. The samples (Alloy Steel 9310) are analyzed by a Vicker Hardness Tester to study the hardness and X-ray Photoelectron Spectroscopy (XPS) to study implantation density and depth. Different magnetic fields are also applied on samples to reduce the energy loss and secondary emission. Higher efficiency of implantation is expected from this experiment and the results will be presented. Hilldale Undergraduate/Faculty Research Fellowship of University of Wisconsin-Madison; Professor Cary Forest's Kellett Mid-Career Faculty Award.

  1. KCP Activities Supporting the W76LEP Stress Cushions and LK3626 RTV Replacement Material Development

    Energy Technology Data Exchange (ETDEWEB)

    J. W. Schneider

    2009-10-01

    The S-5370 RTV blown foam previously produced by Dow Corning is no longer commercially available. The S-5370 material has been used on all of Los Alamos National Laboratory (LANL) programs to manufacture Stress Cushions up through the W88. The Kansas City Plant (KCP) did not have a sufficient supply of S-5370 material to cover the schedule requirements for the Program. This report provides information on the numerous activities conducted at KCP involving the development of the Program Stress Cushion and replacement RTV material.

  2. Effect of addition of bioactive materials on dental implantation based on the examination histology (Literature review

    Directory of Open Access Journals (Sweden)

    Richard Tetelepta

    2016-06-01

    Full Text Available Dental implants in alveolar bone is one method to provide retention and support the strength of the installation of dentures, denture prosthesis either fixed or removable. Long-term success of dental implants is highly dependent on rapid healing with secure integration into the jawbone. Performance of the implant is indicated by the mechanism of interaction between the implant material with the surrounding tissue. To overcome these problems, various surface modification of titanium implants have been done so are bioactive resulting in osseointegration, which are made of titanium into the bioactive surface through modification of the chemical composition and surface topography corresponding implant as retention of bone cells on the surface of titanium implants. Histology picture of microstructural characterization by Scanning Electron Microscope (SEM shows the hydroxyapatite found in the outermost surface of the implant is a surface modification that aims to add the bioactivity of attachment of the implant and the bone tissue, so that the resulting mechanical and biological adhesion was good.

  3. A Review on Biodentine, a Contemporary Dentine Replacement and Repair Material

    Science.gov (United States)

    Malkondu, Özlem; Kazandağ, Meriç Karapinar; Kazazoğlu, Ender

    2014-01-01

    Biodentine is a calcium-silicate based material that has drawn attention in recent years and has been advocated to be used in various clinical applications, such as root perforations, apexification, resorptions, retrograde fillings, pulp capping procedures, and dentine replacement. There has been considerable research performed on this material since its launching; however, there is scarce number of review articles that collates information and data obtained from these studies. Therefore, this review article was prepared to provide the reader with a general picture regarding the findings about various characteristics of the material. The results of a PubMed search were classified and presented along with some critical comments where necessary. The review initially focuses on various physical properties of the material with subheadings and continues with biocompatibility. Another section includes the review of studies on Biodentine as a vital pulp treatment material and the article is finalized with the summary of some case reports where the material has been used. PMID:25025034

  4. Experimental and computational analysis of micromotions of an uncemented femoral knee implant using elastic and plastic bone material models.

    Science.gov (United States)

    Berahmani, Sanaz; Janssen, Dennis; Verdonschot, Nico

    2017-08-16

    It is essential to calculate micromotions at the bone-implant interface of an uncemented femoral total knee replacement (TKR) using a reliable computational model. In the current study, experimental measurements of micromotions were compared with predicted micromotions by Finite Element Analysis (FEA) using two bone material models: linear elastic and post-yield material behavior, while an actual range of interference fit was simulated. The primary aim was to investigate whether a plasticity model is essential in order to calculate realistic micromotions. Additionally, experimental bone damage at the interface was compared with the FEA simulated range. TKR surgical cuts were applied to five cadaveric femora and micro- and clinical CT- scans of these un-implanted specimens were made to extract geometrical and material properties, respectively. Micromotions at the interface were measured using digital image correlation. Cadaver-specific FEA models were created based on the experimental set-up. The average experimental micromotion of all specimens was 53.1±42.3µm (mean±standard deviation (SD)), which was significantly higher than the micromotions predicted by both models, using either the plastic or elastic material model (26.5±23.9µm and 10.1±10.1µm, respectively; p-valuematerial models). The difference between the two material models was also significant (p-value<0.001). The predicted damage had a magnitude and distribution which was comparable to the experimental bone damage. We conclude that, although the plastic model could not fully predict the micro motions, it is more suitable for pre-clinical assessment of a press-fit TKR implant than using an elastic bone model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Research Update: Materials design of implantable nanogenerators for biomechanical energy harvesting

    Directory of Open Access Journals (Sweden)

    Jun Li

    2017-07-01

    Full Text Available Implantable nanogenerators are rapidly advanced recently as a promising concept for harvesting biomechanical energy in vivo. This review article presents an overview of the most current progress of implantable piezoelectric nanogenerator (PENG and triboelectric nanogenerator (TENG with a focus on materials selection, engineering, and assembly. The evolution of the PENG materials is discussed from ZnO nanostructures, to high-performance ferroelectric perovskites, to flexible piezoelectric polymer mesostructures. Discussion of TENGs is focused on the materials and surface features of friction layers, encapsulation materials, and device integrations. Challenges faced by this promising technology and possible future research directions are also discussed.

  6. Research Update: Materials design of implantable nanogenerators for biomechanical energy harvesting

    Science.gov (United States)

    Li, Jun; Wang, Xudong

    2017-07-01

    Implantable nanogenerators are rapidly advanced recently as a promising concept for harvesting biomechanical energy in vivo. This review article presents an overview of the most current progress of implantable piezoelectric nanogenerator (PENG) and triboelectric nanogenerator (TENG) with a focus on materials selection, engineering, and assembly. The evolution of the PENG materials is discussed from ZnO nanostructures, to high-performance ferroelectric perovskites, to flexible piezoelectric polymer mesostructures. Discussion of TENGs is focused on the materials and surface features of friction layers, encapsulation materials, and device integrations. Challenges faced by this promising technology and possible future research directions are also discussed.

  7. Finite Element Analysis of the Effect of Superstructure Materials and Loading Angle on Stress Distribution around the Implant

    OpenAIRE

    Jafari K; Vojdani M; Mahdavi F; Heidary H

    2014-01-01

    Statement of Problem: A general process in implant design is to determine the reason of possible problems and to find the relevant solutions. The success of the implant depends on the control technique of implant biomechanical conditions. Objectives: The goal of this study was to evaluate the influence of both abutment and framework materials on the stress of the bone around the implant by using threedimensional finite element analysis. Materials and Methods: A three-dimensi...

  8. Replacement of missing anterior tooth using screw retained implant prosthesis in the esthetic zone: a case report with 3 years of follow up.

    Science.gov (United States)

    Ahmad, Manawar; Dhanasekar, B; Aparna, I N; Naim, Hina

    2014-09-01

    As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminates unaesthetic screw access holes; have passive fit of castings; reduce stress to splinted implants because of minor misfit of the framework; reduced complexity of lab procedures; enhanced esthetics; reduced cost factors and non disrupted morphology of the occlusal table. This case report presents the replacement of missing left central incisor using screw-retained implant prosthesis due to palatal trajectory of the implant placement and inadequate abutment height for retention of cement retained prosthesis.

  9. 10 CFR 35.2075 - Records of the release of individuals containing unsealed byproduct material or implants...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of the release of individuals containing unsealed byproduct material or implants containing byproduct material. 35.2075 Section 35.2075 Energy NUCLEAR... individuals containing unsealed byproduct material or implants containing byproduct material. (a) A...

  10. Magnesium-containing layered double hydroxides as orthopaedic implant coating materials--An in vitro and in vivo study.

    Science.gov (United States)

    Weizbauer, Andreas; Kieke, Marc; Rahim, Muhammad Imran; Angrisani, Gian Luigi; Willbold, Elmar; Diekmann, Julia; Flörkemeier, Thilo; Windhagen, Henning; Müller, Peter Paul; Behrens, Peter; Budde, Stefan

    2016-04-01

    The total hip arthroplasty is one of the most common artificial joint replacement procedures. Several different surface coatings have been shown to improve implant fixation by facilitating bone ingrowth and consequently enhancing the longevity of uncemented orthopaedic hip prostheses. In the present study, two different layered double hydroxides (LDHs), Mg-Fe- and Mg-Al-LDH, were investigated as potential magnesium (Mg)-containing coating materials for orthopaedic applications in comparison to Mg hydroxide (Mg(OH)2). In vitro direct cell compatibility tests were carried out using the murine fibroblast cell line NIH 3T3 and the mouse osteosarcoma cell line MG 63. The host response of bone tissue was evaluated in in vivo experiments with nine rabbits. Two cylindrical pellets (3 × 3 mm) were implanted into each femoral condyle of the left hind leg. The samples were analyzed histologically and with μ-computed tomography (μ-CT) 6 weeks after surgery. An in vitro cytotoxicity test determined that more cells grew on the LDH pellets than on the Mg(OH)2-pellets. The pH value and the Mg(2+) content of the cell culture media were increased after incubation of the cells on the degradable samples. The in vivo tests demonstrated the formation of fibrous capsules around Mg(OH)2 and Mg-Fe-LDH. In contrast, the host response of the Mg-Al-LDH samples indicated that this Mg-containing biomaterial is a potential candidate for implant coating.

  11. Surface modification of polymeric materials by plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Ricky K.Y. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Cheung, I.T.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Mei, Y.F. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Shek, C.H. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Siu, G.G. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: paul.chu@cityu.edu.hk; Yang, W.M. [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Leng, Y.X. [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Huang, Y.X. [State Key Laboratory of Welding Production Technology, Harbin Institute of Technology, Harbin (China); Tian, X.B. [State Key Laboratory of Welding Production Technology, Harbin Institute of technology, Harbin (China); Yang, S.Q. [State Key Laboratory of Welding Production Technology, Harbin Institute of Technology, Harbin (China)

    2005-08-01

    Polymer surfaces typically have low surface tension and high chemical inertness and so they usually have poor wetting and adhesion properties. The surface properties can be altered by modifying the molecular structure using plasma immersion ion implantation (PIII). In this work, Nylon-6 was treated using oxygen/nitrogen PIII. The observed improvement in the wettability is due to the oxygenated and nitrogen (amine) functional groups created on the polymer surface by the plasma treatment. X-ray photoelectron spectroscopy (XPS) results show that nitrogen and oxygen plasma implantation result in C-C bond breaking to form the imine and amine groups as well as alcohol and/or carbonyl groups on the surface. The water contact angle results reveal that the surface wetting properties depend on the functional groups, which can be adjusted by the ratio of oxygen-nitrogen mixtures.

  12. 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...

  13. 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

  14. The effect of insert conformity and material on total knee replacement wear.

    Science.gov (United States)

    Abdelgaied, Abdellatif; Brockett, Claire L; Liu, Feng; Jennings, Louise M; Jin, Zhongmin; Fisher, John

    2014-01-01

    The mean average life is increasing; therefore, there is a need to increase the lifetime of the prostheses. To fulfil this requirement, new prosthetic designs and materials are being introduced. Two of the design parameters that may affect wear of total knee replacements, and hence the expected lifetime, are the insert conformity and material. Computational models have been used extensively for wear prediction and optimisation of artificial knee designs. The objective of the present study was to use a previously validated non-dimensional wear coefficient-based computational wear model to investigate the effect of insert conformity and material on the predicted wear in total knee replacements. Four different inserts (curved, lipped, partial flat and custom flat), with different conformity levels, were tested against the same femoral and under two different kinematic inputs (intermediate and high), with different levels of cross-shear. The insert bearing materials were either conventional or moderately cross-linked ultra-high molecular weight polyethylene (UHMWPE). Wear predictions were validated against the experimental data from Leeds knee simulation tests. The predicted wear rates for the curved insert (most conformed) were more than three times those for the flat insert (least conformed). In addition, the computationally predicted average volumetric wear rates for moderately cross-linked UHMWPE bearings were less than half of their corresponding conventional UHMWPE bearings. Moreover, the wear of the moderately cross-linked UHMWPE was shown to be less dependent on the degree of cross-shear, compared to conventional UHMWPE. These results along with supporting experimental studies provide insight into the design variables, which may reduce wear in knee replacements.

  15. A simple ion implanter for material modifications in agriculture and gemmology

    Science.gov (United States)

    Singkarat, S.; Wijaikhum, A.; Suwannakachorn, D.; Tippawan, U.; Intarasiri, S.; Bootkul, D.; Phanchaisri, B.; Techarung, J.; Rhodes, M. W.; Suwankosum, R.; Rattanarin, S.; Yu, L. D.

    2015-12-01

    In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X-Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

  16. A simple ion implanter for material modifications in agriculture and gemmology

    Energy Technology Data Exchange (ETDEWEB)

    Singkarat, S. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Wijaikhum, A. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Suwannakachorn, D.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Intarasiri, S. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Bootkul, D. [Department of General Science, Faculty of Science, Srinakharinwirot University, Bangkok 10110 (Thailand); Phanchaisri, B.; Techarung, J. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Rhodes, M.W.; Suwankosum, R.; Rattanarin, S. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2015-12-15

    In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X–Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

  17. Is Graphene a Promising Nano-Material for Promoting Surface Modification of Implants or Scaffold Materials in Bone Tissue Engineering?

    Science.gov (United States)

    Gu, Ming; Liu, Yunsong; Chen, Tong; Du, Feng; Zhao, Xianghui; Xiong, Chunyang

    2014-01-01

    Bone tissue engineering promises to restore bone defects that are caused by severe trauma, congenital malformations, tumors, and nonunion fractures. How to effectively promote the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) or seed cells has become a hot topic in this field. Many researchers are studying the ways of conferring a pro-osteodifferentiation or osteoinductive capability on implants or scaffold materials, where osteogenesis of seed cells is promoted. Graphene (G) provides a new kind of coating material that may confer the pro-osteodifferentiation capability on implants and scaffold materials by surface modification. Here, we review recent studies on the effects of graphene on surface modifications of implants or scaffold materials. The ability of graphene to improve the mechanical and biological properties of implants or scaffold materials, such as nitinol and carbon nanotubes, and its ability to promote the adhesion, proliferation, and osteogenic differentiation of MSCs or osteoblasts have been demonstrated in several studies. Most previous studies were performed in vitro, but further studies will explore the mechanisms of graphene's effects on bone regeneration, its in vivo biocompatibility, its ability to promote osteodifferentiation, and its potential applications in bone tissue engineering. PMID:24447041

  18. Wear behaviour of laser melted an ion implanted materials.

    NARCIS (Netherlands)

    Beurs, Hans de

    1988-01-01

    The emphasis in this thesis is on the development of wear resistant materials by laser melting. Furthermore, the principle aim is to search for the dislocation characteristics common to the wear process in heterogeneous materials. ... Zie: Summary

  19. Biofilm formation on dental restorative and implant materials.

    Science.gov (United States)

    Busscher, H J; Rinastiti, M; Siswomihardjo, W; van der Mei, H C

    2010-07-01

    Biomaterials for the restoration of oral function are prone to biofilm formation, affecting oral health. Oral bacteria adhere to hydrophobic and hydrophilic surfaces, but due to fluctuating shear, little biofilm accumulates on hydrophobic surfaces in vivo. More biofilm accumulates on rough than on smooth surfaces. Oral biofilms mostly consist of multiple bacterial strains, but Candida species are found on acrylic dentures. Biofilms on gold and amalgam in vivo are thick and fully covering, but barely viable. Biofilms on ceramics are thin and highly viable. Biofilms on composites and glass-ionomer cements cause surface deterioration, which enhances biofilm formation again. Residual monomer release from composites influences biofilm growth in vitro, but effects in vivo are less pronounced, probably due to the large volume of saliva into which compounds are released and its continuous refreshment. Similarly, conflicting results have been reported on effects of fluoride release from glass-ionomer cements. Finally, biomaterial-associated infection of implants and devices elsewhere in the body is compared with oral biofilm formation. Biomaterial modifications to discourage biofilm formation on implants and devices are critically discussed for possible applications in dentistry. It is concluded that, for dental applications, antimicrobial coatings killing bacteria upon contact are more promising than antimicrobial-releasing coatings.

  20. The electrochemical behavior of metallic implant materials as an indicator of their biocompatibility.

    Science.gov (United States)

    Zitter, H; Plenk, H

    1987-07-01

    This study introduces a simple in vitro arrangement to measure current densities of implant metals. The in vivo condition of a metallic implant lying in tissues exhibiting different redox potentials is simulated in so-called straddle tests by applying a constant potential difference of 250 mV in saline containing the stable, fast-reacting redox system K4Fe(CN)6/K3Fe(CN)6. From a variety of corrosion-resistant implant metals and alloys, gold showed the highest current densities, followed by the stainless steel, the cobalt-based alloy, and the TiAIV-alloy. The pure metals titanium, niobium, and tantalum showed the lowest values. This can be explained by the stable oxide layer on these base metals, preventing an exchange of electrons and thus any redox reaction. This rating of metallic implant materials based on in vitro measurements of current densities is in good accordance with their biocompatibility rating reported from in vivo experiences. It seems that simple and cheap electrochemical tests allow an even more precise differentiation of the suitability of metallic materials for implant purposes than most of the conventional implantation tests, considering that biocompatibility is not only determined by corrosion products, but also by exchange currents and reaction products of redox processes involving tissue compounds.

  1. The effect of plasma surface treatment on the bioactivity of titanium implant materials (in vitro).

    Science.gov (United States)

    Abdelrahim, Ramy A; Badr, Nadia A; Baroudi, Kusai

    2016-01-01

    The surface of an implantable biomaterial plays a very important role in determining the biocompatibility, osteoinduction, and osteointegration of implants because it is in intimate contact with the host bone and soft tissues. This study was aimed to assess the effect of plasma surface treatment on the bioactivity of titanium alloy (Ti-6Al-4V). Fifteen titanium alloy samples were used in this study. The samples were divided into three groups (with five samples in each group). Five samples were kept untreated and served as control (group A). Another five plasma samples were sprayed for nitrogen ion implantation on their surfaces (group B) and the last five samples were pre-etched with acid before plasma treatment (group C). All the investigated samples were immersed for 7 days in Hank's balanced salt solution (HBSS) which was used as a simulating body fluid (SBF) at pH 7.4 and 37°C. HBSS was renewed every 3 days. The different surfaces were characterized by X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDXA), and Fourier Transformation Infrared Spectroscopy (FTIR). Nitriding of Ti-alloy samples via plasma nitrogen ion implantation increased the bioactivity of titanium. Moreover, the surface topography affected the chemical structure of the formed apatite. Increasing the surface roughness enhanced the bioactivity of the implant material. Nitridation can be exploited as an effective way to promote the formation of bone-like material on the implant surface.

  2. Superelastic Orthopedic Implant Coatings

    Science.gov (United States)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  3. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    OpenAIRE

    Marzieh Alikhasi; Hakimeh Siadat; Elaheh Beyabanaki; Mohammad Javad Kharazifard

    2015-01-01

    Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials.Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl siloxane (PVS) impressions with square and conical transfer copings using open tray and closed tray ...

  4. Evaluation of implant calcium-phosphate materials depending on their mineral content

    Directory of Open Access Journals (Sweden)

    I. A. Talashova

    2012-01-01

    Full Text Available Biocompatibility of original implant calcium-phosphate materials was evaluated in the experiment on animals. The methods of radiological electron-probe microanalysis (REMA and light and scan electron microscopy (SEM were used. Studied materials had the properties of biodegradation, osteoinduction and osteoconduction at different extent. The materials with the composite maximally close to the the bone tissue had the greatest grade of biocompatibility.

  5. A Review on Biodentine, a Contemporary Dentine Replacement and Repair Material

    Directory of Open Access Journals (Sweden)

    Özlem Malkondu

    2014-01-01

    Full Text Available Biodentine is a calcium-silicate based material that has drawn attention in recent years and has been advocated to be used in various clinical applications, such as root perforations, apexification, resorptions, retrograde fillings, pulp capping procedures, and dentine replacement. There has been considerable research performed on this material since its launching; however, there is scarce number of review articles that collates information and data obtained from these studies. Therefore, this review article was prepared to provide the reader with a general picture regarding the findings about various characteristics of the material. The results of a PubMed search were classified and presented along with some critical comments where necessary. The review initially focuses on various physical properties of the material with subheadings and continues with biocompatibility. Another section includes the review of studies on Biodentine as a vital pulp treatment material and the article is finalized with the summary of some case reports where the material has been used.

  6. Influence of Abutment Material on the Stress of Implant-supported All-ceramic Single Crown

    Institute of Scientific and Technical Information of China (English)

    GAO Shaohuai; DUAN Haiying; LI Zhiyong

    2012-01-01

    In order to investigate the influence of abutment material on the stress of implant-supported all-ceramic single crown,a 3D finite element model of implant-supported mandibular first premolar was computed by COSMOS/M 2.85 software.Alumina,zirconia,and titanium were used as abutment materials respectively.Vertical 600 N and horizontal 225 N load was applied on the occlusal surface.The results show that the stress distribution of implant-supported single crown was similar for different abutment materials.Maximum stresses within the crown were higher when titanium abutment was used.Maximum stress of titanium abutment was lower than that of ceramic abutment.Within the screw and fixture,maximum stresses had no difference under vertical loading but higher as titanium abutment was used under horizontal loading.There was no difference of maximum stress within the bone when different abutment materials were used.The present findings indicate that the abutment material had no influence on the stress distribution of implant-supported allceramic single crown but maximum stress when the titanium abutment was lower than that of ceramic abument.

  7. 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.

  8. Influence of limestone waste as partial replacement material for sand and marble powder in concrete properties

    Directory of Open Access Journals (Sweden)

    Omar M. Omar

    2012-12-01

    Full Text Available Green concrete are generally composed of recycling materials as hundred or partial percent substitutes for aggregate, cement, and admixture in concrete. Limestone waste is obtained as a by-product during the production of aggregates through the crushing process of rocks in rubble crusher units. Using quarry waste as a substitute of sand in construction materials would resolve the environmental problems caused by the large-scale depletion of the natural sources of river and mining sands. This paper reports the experimental study undertaken to investigate the influence of partial replacement of sand with limestone waste (LSW, with marble powder (M.P as an additive on the concrete properties. The replacement proportion of sand with limestone waste, 25%, 50%, and 75% were practiced in the concrete mixes except in the concrete mix. Besides, proportions of 5%, 10% and 15% marble powder were practiced in the concrete mixes. The effects of limestone waste as fine aggregate on several fresh and hardened properties of the concretes were investigated. The investigation included testing of compressive strength, indirect tensile strength, flexural strength, modulus of elasticity, and permeability. It was found that limestone waste as fine aggregate enhanced the slump test of the fresh concretes. But the unit weight concretes were not affected. However, the good performance was observed when limestone waste as fine aggregate was used in presence of marble powder.

  9. Assessment of human gingival fibroblast interaction with dental implant abutment materials.

    Science.gov (United States)

    Rutkunas, Vygandas; Bukelskiene, Virginija; Sabaliauskas, Vaidotas; Balciunas, Evaldas; Malinauskas, Mangirdas; Baltriukiene, Daiva

    2015-04-01

    The biocompatibility of dental implant abutment materials depends on numerous factors including the nature of the material, its chemical composition, roughness, texture, hydrophilicity and surface charge. The aim of the present study was to compare the viability and adhesion strength of human gingival fibroblasts (HGFs) grown on several dental materials used in implant prosthodontics. Surfaces of the tested materials were assessed using an optical imaging profiler. For material toxicity and cellular adhesion evaluation, primary human gingival fibroblast cells were used. To evaluate the strength of cellular adhesion, gingival fibroblasts were cultured on the tested materials and subjected to lateral shear forces by applying 300 and 500 rpm shaking intensities. Focal adhesion kinase (FAK) expression and phosphorylation in cells grown on the specimens were registered by cell-based ELISA. There was a tendency of fibroblast adhesion strength to decrease in the following order: sandblasted titanium, polished titanium, sandblasted zirconium oxide, polished zirconium oxide, gold-alloy, chrome-cobalt alloy. Higher levels of total as well as phospho-FAK protein were registered in HGFs grown on roughened titanium. Material type and surface processing technique have an impact on gingival fibroblast interaction with dental implant abutment materials.

  10. Evaluation of implant-materials as cell carriers for dental stem cells under in vitro conditions.

    Science.gov (United States)

    Gosau, Martin; Viale-Bouroncle, Sandra; Eickhoff, Hannah; Prateeptongkum, Esthera; Reck, Anja; Götz, W; Klingelhöffer, Christoph; Müller, Steffen; Morsczeck, Christian

    2015-12-01

    Dental stem cells in combination with implant materials may become an alternative to autologous bone transplants. For tissue engineering different types of soft and rigid implant materials are available, but little is known about the viability and the osteogenic differentiation of dental stem cells on these different types of materials. According to previous studies we proposed that rigid bone substitute materials are superior to soft materials for dental tissue engineering. We evaluated the proliferation, the induction of apoptosis and the osteogenic differentiation of dental stem/progenitor cells on a synthetic bone-like material and on an allograft product. The soft materials silicone and polyacrylamide (PA) were used for comparison. Precursor cells from the dental follicle (DFCs) and progenitor cells from the dental apical papilla of retained third molar tooth (dNC-PCs) were applied as dental stem cells in our study. Both dental cell types attached and grew on rigid bone substitute materials, but they did not grow on soft materials. Moreover, rigid bone substitute materials only sustained the osteogenic differentiation of dental stem cells, although the allograft product induced apoptosis in both dental cell types. Remarkably, PA, silicone and the synthetic bone substitute material did not induce the apoptosis in dental cells. Our work supports the hypothesis that bone substitute materials are suitable for dental stem cell tissue engineering. Furthermore, we also suggest that the induction of apoptosis by bone substitute materials may not impair the proliferation and the differentiation of dental stem cells.

  11. Cranioplasty and Craniofacial Reconstruction: A Review of Implant Material, Manufacturing Method and Infection Risk

    Directory of Open Access Journals (Sweden)

    Jeremy Kwarcinski

    2017-03-01

    Full Text Available Analysis of current literature highlights a wide variation in reported infection risk for different materials in cranial repair. The purpose of these composite materials are to mimic natural bone and assist in restoring function (structurally and aesthetically to the human skull. This review aims to examine the meta-data in order to provide an amalgamated overview of potential trends between implant material, manufacturing method and infection risk, in order to provide a core reference point for future studies surrounding emerging biomedical materials in the fields of cranioplasty by providing base point for understanding the capabilities and limitations of current technologies. Methods: A search for articles was conducted, with the following criteria seen as fundamental in providing an accurate picture of the current landscape: publication in the last decade, provision of a numerical value for both number of implants and infection cases, patient sample of 10+, adult patients, and cranioplasty/cranial repair. Results: A total of 41 articles were seen to meet the author’s inclusion criteria. Average infection rates per material ranged between 2.04% and 10.98%. The results indicate that there is variation between materials in regards to total infection risk, however, depending on the materials compared, this value may be insignificant. Alternative risk factors associated with infection, including surgical time, revisions and previous infection, have a greater impact on infection potential than material variation. Comparison of fabrication methods did highlight a notable effect on average infection rate. Trends can be observed showing that materials with greater levels of surface interaction and active support of tissue ingrowth presented greater infection resistance. Such characteristics are due to the physical structures of the implants. Conclusions: It can be said that the manufacturing methods can influence biomedical materials to assist in

  12. Design-Optimization and Material Selection for a Proximal Radius Fracture-Fixation Implant

    Science.gov (United States)

    Grujicic, M.; Xie, X.; Arakere, G.; Grujicic, A.; Wagner, D. W.; Vallejo, A.

    2010-11-01

    The problem of optimal size, shape, and placement of a proximal radius-fracture fixation-plate is addressed computationally using a combined finite-element/design-optimization procedure. To expand the set of physiological loading conditions experienced by the implant during normal everyday activities of the patient, beyond those typically covered by the pre-clinical implant-evaluation testing procedures, the case of a wheel-chair push exertion is considered. Toward that end, a musculoskeletal multi-body inverse-dynamics analysis is carried out of a human propelling a wheelchair. The results obtained are used as input to a finite-element structural analysis for evaluation of the maximum stress and fatigue life of the parametrically defined implant design. While optimizing the design of the radius-fracture fixation-plate, realistic functional requirements pertaining to the attainment of the required level of the devise safety factor and longevity/lifecycle were considered. It is argued that the type of analyses employed in the present work should be: (a) used to complement the standard experimental pre-clinical implant-evaluation tests (the tests which normally include a limited number of daily-living physiological loading conditions and which rely on single pass/fail outcomes/decisions with respect to a set of lower-bound implant-performance criteria) and (b) integrated early in the implant design and material/manufacturing-route selection process.

  13. Guided bone regeneration for immediate non-submerged implant placement using bioabsorbable materials in Beagle dogs.

    Science.gov (United States)

    Brunel, G; Benqué, E; Elharar, F; Sansac, C; Duffort, J F; Barthet, P; Baysse, E; Miller, N

    1998-10-01

    The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri-implant defects after placement of non-submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow-screw non-submerged dental implants. For each animal, the coronal peri-implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site; 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures (P > 0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%, P < 0.05) or sites grafted with HA (22.2%, P < 0.02). Total BIC in sites treated with the HA-membrane combination (43%) was only significantly different from sites treated with HA (P < 0.05). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.

  14. Plasma immersion ion implantation for the efficient surface modification of medical materials

    Energy Technology Data Exchange (ETDEWEB)

    Slabodchikov, Vladimir A., E-mail: dipis1991@mail.ru; Borisov, Dmitry P., E-mail: borengin@mail.ru; Kuznetsov, Vladimir M., E-mail: kuznetsov@rec.tsu.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-10-27

    The paper reports on a new method of plasma immersion ion implantation for the surface modification of medical materials using the example of nickel-titanium (NiTi) alloys much used for manufacturing medical implants. The chemical composition and surface properties of NiTi alloys doped with silicon by conventional ion implantation and by the proposed plasma immersion method are compared. It is shown that the new plasma immersion method is more efficient than conventional ion beam treatment and provides Si implantation into NiTi surface layers through a depth of a hundred nanometers at low bias voltages (400 V) and temperatures (≤150°C) of the substrate. The research results suggest that the chemical composition and surface properties of materials required for medicine, e.g., NiTi alloys, can be successfully attained through modification by the proposed method of plasma immersion ion implantation and by other methods based on the proposed vacuum equipment without using any conventional ion beam treatment.

  15. Titanium implant insertion into dog alveolar ridges augmented by allogenic material

    DEFF Research Database (Denmark)

    Pinholt, E M; Haanaes, H R; Donath, K

    1994-01-01

    The purpose of this investigation was to evaluate whether titanium endosseous implants would osseointegrate in dog alveolar ridges augmented by allogenic material. In 8 dogs en bloc resection, including 2 pre-molars, was performed bilaterally in the maxilla and the mandible. After a healing perio...

  16. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    Directory of Open Access Journals (Sweden)

    Antônio Francisco GRANDO

    2014-06-01

    Full Text Available Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application. Results: The results showed that both variables had influence on the studied factors (deformation by compression and tension. Conclusion: The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant.

  17. Maxillary Sinus Membrane Elevation With Simultaneous Installation of Implants Without the Use of a Graft Material

    DEFF Research Database (Denmark)

    Starch-Jensen, Thomas; Schou, Søren

    2017-01-01

    in sinuses augmented with blood clot compared to bone substitute, whereas no significant difference was found when compared to autogenous bone. Noncomparative studies demonstrated high long-term implant survival and new bone formation after sinus membrane elevation without graft material. CONCLUSIONS: Sinus...

  18. Socket seal surgery: Clinical uses in implant dentistry and guided bone regeneration procedures for single tooth replacement in the esthetic zone.

    Science.gov (United States)

    Negri, Bruno; Zuhr, Otto; Fickl, Stefan; Ciurana, Xavier Rodríguez; Navarro Martínez, José Manuel; Blanco, Víctor Méndez

    2016-02-01

    Restoring failing anterior teeth with a dental implant is considered a complex treatment even with thorough biologic knowledge of the situation. The goal is to produce a result in which the labial soft tissues and the papillae remain stable over time. Treatment of the fresh extraction socket in the alveolar ridge presents a challenge in everyday clinical practice. Regardless of the subsequent treatment, maintenance of the ridge contour will frequently facilitate all further therapeutic steps. Socket seal surgery and socket preservation in combination with immediate, early, or delayed implant placement can be valuable procedures for single tooth replacement. However, their potential as ridge preservation techniques in these different situations still needs to be demonstrated. The use of these procedures is illustrated in three consecutive cases.

  19. [Implant materials for the internal fixation of midfacial fractures].

    Science.gov (United States)

    Stuck, B A; Heller, T

    2011-11-01

    The material used for osteosynthesis plays a crucial role in the management of facial fractures. Plates need to be flexible enough to be bent and should not be palpable through the skin, while ensuring stable fixation und adequate biocompatibility. Although stainless steel was initially the material of choice, titanium has become the standard material due to its superior biocompatibility. While the explantation of titanium plates and screws appears unnecessary in general, it should be considered in cases of dislocation, cosmetic concerns, pain and infection. Due to their limited initial stability and a potential increase in local complications, resorbable materials based on polymeric lactose are used with caution in midfacial fractures in adults. Our own retrospective study comparing the postoperative complications after fixation of lateral midfacial fractures with titanium and resorbable systems demonstrated a low complication rate for both systems (7-8%) and no statistically significant difference between the two. The appropriate material for fixation should be selected based on the localization and severity of the fracture, the experience of the surgeon as well as on the age and overall condition of the patient.

  20. Laser vibrometry for investigation of tympanic membrane implant materials

    Science.gov (United States)

    Zahnert, Thomas; Kuster, Manfred; Vogel, Uwe; Hofmann, Gert; Huettenbrink, Karl-Bernd

    1996-12-01

    The human tympanic membrane has reasonably good sound sensing properties. A destroyed tympanic membrane due to middle ear diseases or traumata may be repaired by different types of grafts. Middle ear surgery mostly uses autologous temporal fascia, cartilage, or cartilage perichondrium transplants. We have investigated the acoustical and mechanical properties of these materials and compared them with human tympanic membrane by constructing an ear canal model completed by an artificial tympanic membrane. Circular stretched human fascia, perichondrium, and cartilage preparations were exposed to static pressures up to 4 kPa and white noise sound pressure levels of 70 dB. The vibrational amplitudes and displacements due to static pressure of the graft material were measured by laser Doppler vibrometry and compared. The thin materials temporal fascia and perichondrium show similar amplitude frequency responses compared to the tympanic membrane for dynamic excitation. The displacement of these materials at static pressures above 4 kPA yields a higher compliance than tympanic membrane. The acoustical and mechanical properties of cartilage transplants change with the thickness of the slices. However, the thinner the cartilage slice combined with lower stability, the more similar is the frequency response with the intact tympanic membrane. The vibration amplitudes decrease more and more for layer thicknesses above 500 micrometers. Cartilage acts as an excellent transplant material which provides a better prognosis than different materials in cases of ventilation disorders with long-term middle ear pressure changes. Large cartilage slice transplants should not exceed layer thicknesses of 500 micrometer in order to prevent drawbacks to the transfer characteristics of the tympanic membrane.

  1. Uso de osteocoral como material de implante en bolsas infraóseas de dientes Monorradiculares

    OpenAIRE

    . Yamilé Hernández Alemán,; Nereyda Riesgo Lobaina; Gladys Rodríguez Méndez; Natividad Alfonso Betancourt

    1999-01-01

    Se evaluó la eficacia del osteocoral como material de implante en el tratamiento de bolsas infraóseas de dientes monorradiculares. Se realizaron 18 injertos en 17 dientes con defectos angulares, en 6 pacientes de ambos sexos; 9 implantes correspondieron al grupo control con hidroxiapatita y 9 al grupo de estudio que fue implantado con osteocoral. Se realizó preparación inicial que incluyó: remoción de cálculos y pulido de las superficies dentarias, educación y motivación sobre el tratamiento ...

  2. Dental Implants.

    Science.gov (United States)

    Griggs, Jason A

    2017-10-01

    Systematic reviews of literature over the period between 2008 and 2017 are discussed regarding clinical evidence for the factors affecting survival and failure of dental implants. The factors addressed include publication bias, tooth location, insertion torque, collar design, implant-abutment connection design, implant length, implant width, bone augmentation, platform switching, surface roughness, implant coatings, and the use of ceramic materials in the implant body and abutment. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Polymer Waste Material as Partial Replacement of Fine Aggregate in Concrete Production

    Directory of Open Access Journals (Sweden)

    D. Dahiru

    2014-05-01

    Full Text Available The aim of the study is to assess the quality of concrete produced with polymer waste as partial replacement of fine aggregate with a view to establishing areas where such concrete can be used. It is an experimental research that entails the following steps: First, the polymer waste material, PWM, was collected from dumps and processed; then its melting point determined. A varying proportion of PWM was used as partial replacement of fine aggregate A nominal mix of 1:3:6 was used to prepare 150×150×150 mm concrete cubes specimens with different proportion of 0, 10, 20 and 30%, respectively PWM partial substitution of fine aggregate. Samples were subjected to workability, compressive and tensile strength tests. Results show that PWM content has inverse relationship with the workability, compressive and tensile strengths. For example, an increase of 30% PWM results to about 53 and 73.3% decrease in compressive and tensile strengths, respectively. The compressive strength of the samples is in the range of 22.8-12.3 N/mm2 while the tensile strength ranges from 1.10-0.56 N/mm2. It is recommended that the concrete should not be used for structural work but such concrete has high water retention capacity. As such, the possibility of using it as a nuclear radiation shield should be investigated.

  4. Effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts

    Directory of Open Access Journals (Sweden)

    Behnaz Ebadian

    2015-01-01

    Full Text Available Background: Different factors such as impression techniques and materials can affect the passive fit between the superstructure and implant. The aim of this study was to determine the effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts. Materials and Methods: Four internal hex implants (Biohorizons Ψ4 mm were placed on a metal maxillary model perpendicular to the horizontal plane in maxillary lateral incisors, right canine and left first premolar areas. Three impression techniques including open tray, closed tray using ball top screw abutments and closed tray using short impression copings and two impression materials (polyether and polyvinyl siloxane were evaluated (n = 60. The changes in distances between implant analogues in mediolateral (x and anteroposterior (y directions and analogue angles in x/z and y/z directions in the horizontal plane on the definitive casts were measured by coordinate measuring machine. The data were analyzed by multivariate two-way analysis of variance and one sample t-test (α = 0.05. Results: No statistical significant differences were observed between different impression techniques and materials. However, deviation and distortion of definitive casts had a significant difference with the master model when short impression copings and polyvinyl siloxane impression material were used (P < 0.05. In open tray technique, there was a significant difference in the rotation of analogs compared with the master model with both impression materials (P < 0.05. Conclusion: There was no difference between open and closed tray impression techniques; however, less distortion and deviation were observed in the open tray technique. In the closed tray impression technique, ball top screw was more accurate than short impression copings.

  5. Optimization of fly ash as sand replacement materials (SRM) in cement composites containing coconut fiber

    Science.gov (United States)

    Nadzri, N. I. M.; Jamaludin, S. B.; Mazlee, M. N.; Jamal, Z. A. Z.

    2016-07-01

    The need of utilizing industrial and agricultural wastes is very important to maintain sustainability. These wastes are often incorporated with cement composites to improve performances in term of physical and mechanical properties. This study presents the results of the investigation of the response of cement composites containing coconut fiber as reinforcement and fly ash use as substitution of sand at different hardening days. Hardening periods of time (7, 14 and 28 days) were selected to study the properties of cement composites. Optimization result showed that 20 wt. % of fly ash (FA) is a suitable material for sand replacement (SRM). Meanwhile 14 days of hardening period gave highest compressive strength (70.12 MPa) from the cement composite containing 9 wt. % of coconut fiber and fly ash. This strength was comparable with the cement without coconut fiber (74.19 MPa) after 28 days of curing.

  6. Estudo experimental da biocompatibilidade de novo material para implante orbitário

    Directory of Open Access Journals (Sweden)

    Rodrigo Beraldi Kormann

    2013-06-01

    Full Text Available OBJETIVO:Avaliar a biocompatibilidade de material FullCure 720®, que é uma resina, na confecção de implante orbitário. Avaliou-se a resposta clínica dos animais, toxicidade sistêmica e a resposta inflamatória crônica. Os animais foram pesados, exames bioquímicos e resposta inflamatória foram avaliados. Foi efetuada evisceração e colocado implante esférico orbitário. Os animais foram acompanhados durante o período de 60 dias, onde se avaliou o comportamento clínico e sinais locais. Após este período, procedeu-se a eutanásia seguida da enucleação. Foi realizada análise macroscópica e histomorfométrica. Os resultados revelaram comportamento normal dos animais, com ausência de exposição ou extrusão dos implantes, morte de algum animal e ausência de toxicidade sistêmica. Houve formação de uma cápsula fibrosa entre a capa escleral e o implante orbitário, resposta inflamatória considerada normal quando em contato com o tecido do coelho. A resina FullCure 720® utilizada como implante orbitário, mostrou-se biocompatível neste estudo.

  7. Effect of UV-photofunctionalization on oral bacterial attachment and biofilm formation to titanium implant material.

    Science.gov (United States)

    de Avila, Erica Dorigatti; Lima, Bruno P; Sekiya, Takeo; Torii, Yasuyoshi; Ogawa, Takahiro; Shi, Wenyuan; Lux, Renate

    2015-10-01

    Bacterial biofilm infections remain prevalent reasons for implant failure. Dental implant placement occurs in the oral environment, which harbors a plethora of biofilm-forming bacteria. Due to its trans-mucosal placement, part of the implant structure is exposed to oral cavity and there is no effective measure to prevent bacterial attachment to implant materials. Here, we demonstrated that UV treatment of titanium immediately prior to use (photofunctionalization) affects the ability of human polymicrobial oral biofilm communities to colonize in the presence of salivary and blood components. UV-treatment of machined titanium transformed the surface from hydrophobic to superhydrophilic. UV-treated surfaces exhibited a significant reduction in bacterial attachment as well as subsequent biofilm formation compared to untreated ones, even though overall bacterial viability was not affected. The function of reducing bacterial colonization was maintained on UV-treated titanium that had been stored in a liquid environment before use. Denaturing gradient gel-electrophoresis (DGGE) and DNA sequencing analyses revealed that while bacterial community profiles appeared different between UV-treated and untreated titanium in the initial attachment phase, this difference vanished as biofilm formation progressed. Our findings confirm that UV-photofunctionalization of titanium has a strong potential to improve outcome of implant placement by creating and maintaining antimicrobial surfaces.

  8. Total dose radiation response of modified commercial silicon-on-insulator materials with nitrogen implanted buried oxide

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhong-Shan; Liu Zhong-Li; Yu Fang; Li Ning

    2012-01-01

    Nitrogen ions of various doses are implanted into the buried oxide (BOX) of commercial silicon-on-insulator (SOI)materials,and subsequent annealings are carried out at various temperatures.The total dose radiation responses of the nitrogen-implanted SOI wafers are characterized by the high frequency capacitance-voltage (C-V) technique after irradiation using a Co-60 source.It is found that there exist relatively complex relationships between the radiation hardness of the nitrogen implanted BOX and the nitrogen implantation dose at different irradiation doses.Fhe experimental results also suggest that a lower dose nitrogen implantation and a higher post-implantation annealing temperature are suitable for improving the radiation hardness of SOI wafer.Based on the measured C-V data,secondary ion mass spectrometry (SIMS),and Fourier transform infrared (FTIR) spectroscopy,the total dose responses of the nitrogen-implanted SOI wafers are discussed.

  9. VENTRAL SPONDYLODESIS BYTITAN IMPLANTS AT SPINE TUMORS

    Directory of Open Access Journals (Sweden)

    A. V. Babkin

    2010-01-01

    Full Text Available At RSPC of traumatology and orthopaedic surgery and Institute of powders metallurgic porous implants are working out which allow complitely replace alio- and autotranplants and improve the surgical technology of interbody spondylodesis. Porous implants, made from mechanic durabilities, are bioinert or biocompatible materials, provide durabilities prime spondylodesis. It doesn't need an additional fixation, realize a possibility to grow a bone matter in powder structure of implants.

  10. Greenhouse gas emissions from the treatment of household plastic containers and packaging: replacement with biomass-based materials.

    Science.gov (United States)

    Yano, Junya; Hirai, Yasuhiro; Sakai, Shin-ichi; Tsubota, Jun

    2014-04-01

    The purpose of this study was to quantify the life-cycle greenhouse gas (GHG) emissions reduction that could be achieved by replacement of fossil-derived materials with biodegradable, biomass-based materials for household plastic containers and packaging, considering a variety of their treatment options. The biomass-based materials were 100% polylactide or a combination of polybutylene succinate adipate and polylactide. A scenario analysis was conducted considering alternative recycling methods. Five scenarios were considered: two for existing fossil-derived materials (the current approach in Japan) and the three for biomass-based materials. Production and waste disposal of 1 m(3) of plastic containers and packaging from households was defined as the functional unit. The results showed that replacement of fossil-derived materials with biomass-based materials could reduce life-cycle GHG emissions by 14-20%. Source separation and recycling should be promoted. When the separate collection ratio reached 100%, replacement with biomass-based materials could potentially reduce GHG emissions by 31.9%. Food containers are a priority for replacement, because they alone could reduce GHG emissions by 10%. A recycling system for biomass-based plastics must be carefully designed, considering aspects such as the transition period from fossil-derived plastics to biomass-based plastics.

  11. Embryo quality before and after slow freezing: Viability, implantation and pregnancy rates in 627 single frozen-thawed embryo replacement cycles following failure of fresh transfer.

    Science.gov (United States)

    Capodanno, Francesco; De Feo, Gaetano; Gizzo, Salvatore; Nicoli, Alessia; Palomba, Stefano; La Sala, Giovanni Battista

    2016-06-01

    Frozen embryo transfer cycles are now common practice, however, various aspects regarding the potential of frozen embryos remain unclear. The main goal of the present study was to assess embryo quality before and after slow freezing procedure, and more specifically blastomere loss and embryo quality as indicator of viability. A single center retrospective analysis of single frozen-thawed embryo replacements (s-FER) was performed. The embryo quality before and after slow freezing and thawing, implantation, and pregnancy rates were recorded. One hundred and twenty seven s-FER were included in the final analysis. The probability of achieving an ongoing pregnancy was significantly associated with embryo quality and the percentage of blastomere loss after thawing. Considering thawed embryos, a non-significant difference in term of implantation rate was observed, regardless to their post-thawing quality and the percentage of blastomeres loss. In conclusion, current data suggest that thawed embryos are capable of implantation regardless of their morphological quality and the degree of cryoinjury sustained.

  12. Materials directed to implants for repairing Central Nervous System

    Energy Technology Data Exchange (ETDEWEB)

    Canillas, M.; Moreno-Burriel, B.; Chinarro, E.

    2014-07-01

    Central Nervous System (CNS) can be damaged by a wide range of injuries and disorders which entail permanent disability in some cases. Moreover, CNS repairing process presents some complications. The natural repair mechanism, which consists on the glial scar formation, is triggered by the inflammatory process. Molecules delivered during these processes, inflammation and glial scar formation as well as oxygen and glucose deficiencies due to the injury, create an inhibitory environment for axon regeneration and remyelination which is known as secondary injury. Biomaterials are taking up an even more important role in repairing CNS. Physicochemical properties of some ceramic materials have inspired different applications to repair CNS as substrates, electrodes or molecule vehicles. Based on their biocompatibility, capability to neutralize reactive species involved in the inflammatory processes and their versatile processing to obtain scaffolds with different shapes and sizes, ceramics are a succulent offer in nervous tissue engineering. Furthermore, their possibilities have been increased with polymeric-ceramics composites development, which have given rise to new interesting horizon. (Author)

  13. Greenhouse gas emissions from the treatment of household plastic containers and packaging: replacement with biomass-based materials.

    OpenAIRE

    Yano, Junya; Hirai, Yasuhiro; Sakai, Shin-ichi; Tsubota, Jun

    2014-01-01

    The purpose of this study was to quantify the life-cycle greenhouse gas (GHG) emissions reduction that could be achieved by replacement of fossil-derived materials with biodegradable, biomass-based materials for household plastic containers and packaging, considering a variety of their treatment options. The biomass-based materials were 100% polylactide or a combination of polybutylene succinate adipate and polylactide. A scenario analysis was conducted considering alternative recycling metho...

  14. Materials directed to implants for repairing Central Nervous System

    Directory of Open Access Journals (Sweden)

    Canillas, M.

    2014-12-01

    Full Text Available Central Nervous System (CNS can be damaged by a wide range of injuries and disorders which entail permanent disability in some cases. Moreover, CNS repairing process presents some complications. The natural repair mechanism, which consists on the glial scar formation, is triggered by the inflammatory process. Molecules delivered during these processes, inflammation and glial scar formation as well as oxygen and glucose deficiencies due to the injury, create an inhibitory environment for axon regeneration and remyelination which is known as “secondary injury”. Biomaterials are taking up an even more important role in repairing CNS. Physicochemical properties of some ceramic materials have inspired different applications to repair CNS as substrates, electrodes or molecule vehicles. Based on their biocompatibility, capability to neutralize reactive species involved in the inflammatory processes and their versatile processing to obtain scaffolds with different shapes and sizes, ceramics are a succulent offer in nervous tissue engineering. Furthermore, their possibilities have been increased with polymeric-ceramics composites development, which have given rise to new interesting horizon.Existen diferentes tipos de lesiones o desordenes del Sistema Nervioso Central (SNC que pueden provocar graves secuelas e incluso en algunos casos una discapacidad permanente. Además, el proceso de reparación del SNC tiene algunas complicaciones. El mecanismo natural de reacción a una lesión, el cual consiste en la formación de una cicatriz glial, es desencadenado por un proceso inflamatorio. Las moléculas liberadas durante estos procesos, la inflamación y formación de la cicatriz glial, así como la deficiencia en oxígeno y glucosa debidos a la lesión, crean un ambiente que inhibe la regeneración axonal creando la llamada “lesión secundaria”. Los biomateriales están adquiriendo un papel cada vez más importante en la reparación de SNC. Las

  15. Renal cortical mercury levels associated with experimental amalgam tattoos: effects of particle size and amount of implanted material.

    Science.gov (United States)

    Eley, B M; Cox, S W

    1987-09-01

    Powdered dental amalgam that had passed through either a 106 microns or a 45 microns sieve was implanted subcutaneously in guinea pigs for periods of up to 2 yr. The renal cortical mercury levels associated with the 106 microns material were on average 16% of those produced by the 45 microns material. A reduction in the amount of 45 microns powder implanted, by a factor of 75%, resulted in a fall of only 27% in renal mercury concentrations. The marked effect of particle size on mercury release may be explained by the large increase in the proportion of implanted material that was degraded within phagocytic cells in the local lesions.

  16. Development of a flow chamber system for the reproducible in vitro analysis of biofilm formation on implant materials

    Science.gov (United States)

    Rath, Henryke; Stumpp, Sascha Nico; Stiesch, Meike

    2017-01-01

    Since the introduction of modern dental implants in the 1980s, the number of inserted implants has steadily increased. Implant systems have become more sophisticated and have enormously enhanced patients’ quality of life. Although there has been tremendous development in implant materials and clinical methods, bacterial infections are still one of the major causes of implant failure. These infections involve the formation of sessile microbial communities, called biofilms. Biofilms possess unique physical and biochemical properties and are hard to treat conventionally. There is a great demand for innovative methods to functionalize surfaces antibacterially, which could be used as the basis of new implant technologies. Present, there are few test systems to evaluate bacterial growth on these surfaces under physiological flow conditions. We developed a flow chamber model optimized for the assessment of dental implant materials. As a result it could be shown that biofilms of the five important oral bacteria Streptococcus gordonii, Streptococcus oralis, Streptococcus salivarius, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans, can be reproducibly formed on the surface of titanium, a frequent implant material. This system can be run automatically in combination with an appropriate microscopic device and is a promising approach for testing the antibacterial effect of innovative dental materials. PMID:28187188

  17. Surface modification of traditional and bioresorbable metallic implant materials for improved biocompatibility

    OpenAIRE

    Walker, Emily Kristine

    2015-01-01

    Due to their strength, elasticity, and durability, a variety of metal alloys are commonly used in medical implants. Traditionally, corrosion-resistant metals have been preferred. These permanent materials can cause negative systemic and local tissue effects in the long-term. Permanent stenting can lead to late-stent thrombosis and in-stent restenosis. Metallic pins and screws for fracture fixation can corrode and fail, cause loss of bone mass, and contribute to inflammation and pain at the im...

  18. Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

    Science.gov (United States)

    Kumar, K. V. Aneesh; Ranganathaiah, C.; Kumarswamy, G. N.; Ravikumar, H. B.

    2016-05-01

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 1012, 1013, 1014 and 1015 ions/cm2. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (1012 to1014 ions/cm2) followed by cross-linking at 1015 ions/cm2 fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.

  19. Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, K. V. Aneesh, E-mail: aneesh1098@gmail.com; Ravikumar, H. B., E-mail: hbr@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Mysore-570006 (India); Ranganathaiah, C., E-mail: cr@physics.uni-mysore.ac.in [Govt. Research Centre, Sahyadri Educational Institutions, Mangalore-575007 (India); Kumarswamy, G. N., E-mail: kumy79@gmail.com [Department of Studies in Physics, Amrita Vishwa Vidyapeetham, Bangalore-560035 (India)

    2016-05-06

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 10{sup 12}, 10{sup 13}, 10{sup 14} and 10{sup 15} ions/cm{sup 2}. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (10{sup 12} to10{sup 14} ions/cm{sup 2}) followed by cross-linking at 10{sup 15} ions/cm{sup 2} fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.

  20. Principles of Human Joint Replacement Design and Clinical Application

    CERN Document Server

    Buechel, Frederick F

    2012-01-01

    Drs. Buechel, an orthopaedic surgeon, and Pappas, a professor of Mechanical Engineering, are the designers of several successful joint replacement systems. The most well-known of these is the pioneering LCS knee replacement. They have written this book for the users and designers of joint replacements. It is an attempt to convey to the reader the knowledge accumulated by the authors during their thirty five year effort on the development of replacement devices for the lower limb for the purpose of aiding the reader in their design and evaluation of joint replacement devices. The early chapters describe the engineering, scientific and medical principles needed for replacement joint evaluation. One must understand the nature and performance of the materials involved and their characteristics in vivo, i.e. the response of the body to implant materials. It is also essential to understand the response of the implants to applied loading and motion, particularly in the hostile physiological environment. A chapter de...

  1. Principles of human joint replacement design and clinical application

    CERN Document Server

    Buechel, Frederick F

    2015-01-01

    This book is written for the users and designers of joint replacements. In its second extended edition it conveys to the reader the knowledge accumulated by the authors during their forty year effort on the development of replacement devices for the lower limb for the purpose of aiding the reader in their design and evaluation of joint replacement devices. The early chapters describe the engineering, scientific and medical principles needed for replacement joint evaluation. One must understand the nature and performance of the materials involved and their characteristics in vivo, i.e. the response of the body to implant materials. It is also essential to understand the response of the implants to applied loading and motion, particularly in the hostile physiological environment. A chapter describes the design methodology now required for joint replacement in the USA and EU countries. The remaining chapters provide a history of joint replacement, an evaluation of earlier and current devices and sample case hist...

  2. Studies on use of Copper Slag as Replacement Material for River Sand in Building Constructions

    Science.gov (United States)

    Madheswaran, C. K.; Ambily, P. S.; Dattatreya, J. K.; Rajamane, N. P.

    2014-09-01

    This work focuses on the use of copper slag, as a partial replacement of sand for use in cement concrete and building construction. Cement mortar mixtures prepared with fine aggregate made up of different proportions of copper slag and sand were tested for use as masonry mortars and plastering. Three masonry wall panels of dimensions 1 × 1 m were plastered. The studies showed that although copper slag based mortar is suitable for plastering, with the increase in copper slag content, the wastage due to material rebounding from the plastered surfaces increases. It is therefore suggested that the copper slag can be used for plastering of floorings and horizontal up to 50 % by mass of the fine aggregate, and for vertical surfaces, such as, brick/block walls it can be used up to 25 %. In this study on concrete mixtures were prepared with two water cement ratios and different proportions of copper slag ranging from 0 % (for the control mix) to 100 % of fine aggregate. The Concrete mixes were evaluated for workability, density, and compressive strength.

  3. 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.

  4. Evaluation of surgical implantation of electronic tags in European eel and effects of different suture materials

    DEFF Research Database (Denmark)

    Thorstad, Eva B.; Økland, Finn; Westerberg, Håkan

    2013-01-01

    Effects of implanting data-storage tags in European eel, Anguilla anguilla, and the suitability of different suture materials (braided permanent silk, permanent monofilament, absorbable and absorbable antibacterial) were examined. The tags consisted of an electronic unit and three floats on a wire....... Antibacterial treatment had no effect on inflammation or healing rates. After 6 months, the tag started to become expelled through the incision in five fish (12%). The internal reaction appeared stronger around the floats, suggesting that the coating material of the floats created a tissue reaction, which...

  5. Metal-nanocluster composites made by ion implantation: A novel third-order nonlinear material

    Energy Technology Data Exchange (ETDEWEB)

    Haglund, R.F. Jr.; Yang, L.; Magruder, R.H. III; Becker, K.; Wittig, J.E. [Vanderbilt Univ., Nashville, TN (United States); White, C.W.; Zhur, R.A. [Oak Ridge National Lab., TN (United States); Yang, L.; Dorsinville, R.; Alfano, R.R. [City Univ. of New York, NY (United States)

    1993-03-01

    We describe our recent studies of metal-insulator nanocluster composites made by ion implantation in such substrates as glass and sapphire. The metal clusters have diameters ranging from 3 to 30 nm. The composites exhibit an electronic nonlinear optical response which is fast on the picosecond time scale. In addition to possibilities for technological application, these materials also offer a way of studying unusual properties of composite materials, such as the quantum confinement of conduction-band electrons and the transverse relaxation time T{sub 2} as a function of cluster size.

  6. Metal-nanocluster composites made by ion implantation: A novel third-order nonlinear material

    Energy Technology Data Exchange (ETDEWEB)

    Haglund, R.F. Jr.; Yang, L.; Magruder, R.H. III; Becker, K.; Wittig, J.E. (Vanderbilt Univ., Nashville, TN (United States)); White, C.W.; Zhur, R.A. (Oak Ridge National Lab., TN (United States)); Yang, L.; Dorsinville, R.; Alfano, R.R. (City Univ. of New York, NY (United States))

    1993-03-01

    We describe our recent studies of metal-insulator nanocluster composites made by ion implantation in such substrates as glass and sapphire. The metal clusters have diameters ranging from 3 to 30 nm. The composites exhibit an electronic nonlinear optical response which is fast on the picosecond time scale. In addition to possibilities for technological application, these materials also offer a way of studying unusual properties of composite materials, such as the quantum confinement of conduction-band electrons and the transverse relaxation time T[sub 2] as a function of cluster size.

  7. Shock absorption capacity of restorative materials for dental implant prostheses: an in vitro study.

    Science.gov (United States)

    Menini, Maria; Conserva, Enrico; Tealdo, Tiziano; Bevilacqua, Marco; Pera, Francesco; Signori, Alessio; Pera, Paolo

    2013-01-01

    To measure the vertical occlusal forces transmitted through crowns made of different restorative materials onto simulated peri-implant bone. The study was conducted using a masticatory robot that is able to reproduce the mandibular movements and forces exerted during mastication. During robot mastication, the forces transmitted onto the simulated peri-implant bone were recorded using nine different restorative materials for the simulated single crown: zirconia, two glass-ceramics, a gold alloy, three composite resins, and two acrylic resins. Three identical sample crowns for each material were used. Each crown was placed under 100 masticatory cycles, occluding with the flat upper surface of the robot to evaluate the vertical forces transmitted. Two-way analysis of variance was used. Alpha was set at .05. The statistical evaluation of the force peaks recorded on the vertical z-axis showed mean values of 641.8 N for zirconia; 484.5 N and 344.5 N, respectively, for the two glass-ceramics; 344.8 N for gold alloy; 293.6 N, 236 N, and 187.4 N, respectively, for the three composite resins; and 39.3 N and 28.3 N, respectively, for the two acrylic resins. Significant differences were found between materials (P material, or gold alloy.

  8. Uso de osteocoral como material de implante en bolsas infraóseas de dientes Monorradiculares

    Directory of Open Access Journals (Sweden)

    . Yamilé Hernández Alemán,

    1999-12-01

    Full Text Available Se evaluó la eficacia del osteocoral como material de implante en el tratamiento de bolsas infraóseas de dientes monorradiculares. Se realizaron 18 injertos en 17 dientes con defectos angulares, en 6 pacientes de ambos sexos; 9 implantes correspondieron al grupo control con hidroxiapatita y 9 al grupo de estudio que fue implantado con osteocoral. Se realizó preparación inicial que incluyó: remoción de cálculos y pulido de las superficies dentarias, educación y motivación sobre el tratamiento recibido, corrección del cepillado igual o mayor al 80 % en la remoción de placa dentobacteriana. Se realizó el implante mediante operación a colgajo, con sutura y colocación de apósito periodontal. Se realizaron radiografías de control a los 14 días, a los 3 y 6 meses. Se controló sistemáticamente la higiene bucal. A los 6 meses se registraron nuevamente los indicadores clínicos. El análisis final de los resultados mostró una disminución estadísticamente significativa en el índice gingival, profundidad de la bolsa al sondeo y movilidad dentaria para ambos materiales implantológicos. No se reportaron grandes diferencias entre éstos para este tamaño de muestra, no hubo reacciones adversas y se logró la permanencia del implante de osteocoral, por lo que se consideró efectivo el tratamiento.Effectivenes of osteocoral as implant material was assessed to treat infraosseous pockets of multirooted teeth. 18 grafts were inserted in 17 teeth with angular defects in 6 patients of both sexes; 9 implants corresponded to control group (hydroxiapatite and 9 corresponded to study group (osteocoral. Initial preparation included: removal of calculus and polishing of dental surface, education and motivation about treatment applied, correction of tooth-brushing equal or greater 80 % in removal of dentobacterial plaque. Implant was inserted by flap surgery using suture and placement of periodontal dresssing. Control X-rays were made within 14 days

  9. Histologic Evaluation of Sinus Grafting Materials After Peri-implantitis-Induced Failure: A Case Series.

    Science.gov (United States)

    Scarano, Antonio; Cholakis, Anastasia Kelekis; Piattelli, Adriano

    This human case series presents the clinical and histologic results of five cases of peri-implantitis with subsequent sinus graft infections. Complications may follow maxillary sinus augmentation procedures. It is possible to have an inflammatory reaction, movement of the implant inside the sinus, formation of an insufficient quantity of osseous tissue, and the production of an oroantral fistula. Complications following maxillary subantral augmentation procedures are relatively rare; however, the risks and benefits of any surgery must be carefully evaluated at the onset. In this case series, bacterial proliferation from infected implants into the grafted biomaterial in sinus cavities was examined. In five cases, removal of infected implants from augmented sinuses did not result in resolution of the infection, but rather in persistence of the infection in the area of the sinus augmentation procedure. Intraoral examination revealed edema/redness in two cases and edema and sinus tract formation in another case. In all cases, surgical curettage of the affected maxillary sinuses was performed. The inserted biomaterials and the accompanying inflammatory tissue infiltrate were totally removed with curettes. The sample was sent for a histopathologic examination. The maxillary sinuses were filled with an autologous platelet gel. Necrotic bone was found lining the different biomaterial grafts. Macrophages were observed around the grafted particles. No blood vessels were observed. This case series is the first to document the spread of infection from an implant surface to the entirety of the graft in the maxillary antrum. Complete removal of all infected bone graft material is the treatment of choice in such cases.

  10. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    Directory of Open Access Journals (Sweden)

    Marzieh Alikhasi

    2016-03-01

    Full Text Available Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials.Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE and 10 regular-body polyvinyl siloxane (PVS impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM. Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM. These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05.Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (P<0.001. Also, the open tray technique showed less angular displacement with the use of PVS impression material. Detail reproduction accuracy was the same in all the groups (P>0.05(.Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction.Keywords: Dental Implants; Dental Impression Materials, Dental Impression Technique

  11. A novel approach to secondary defect reduction in separation by implantation of oxygen (SIMOX) material

    Energy Technology Data Exchange (ETDEWEB)

    Ellingboe, S.L.; Ridgway, M.C. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

    1993-12-31

    The formation of a buried SiO{sub 2} layer in Si for increased radiation hardness, dielectric isolation, and/or higher operating speeds in Si devices has been studied extensively. In the present report, a novel method for improving the final defect structure of SIMOX material is demonstrated for the first time. The concept of ion-beam defect-engineering (IBDE) introduced by Wang et al has been utilised. If defects are introduced at a depth R{sub 1} by irradiation with energetic ions into samples which were previously damaged at a depth R{sub 2}, it is possible to alter the properties of the defects at R{sub 2}, reduce or eliminate damage at R{sub 2}, and/or create gettering sites for defects at R{sub 1} . To elucidate the mechanisms responsible for the secondary defect reduction in annealed SIMOX material, unannealed samples were implanted with Si ions at various energies, while keeping the nuclear energy deposition constant at two depths. It was observed that after annealing, even greater changes in the defect structure are evident. It has been demonstrated that pre-anneal Si irradiation in O-implanted Si can reduce secondary defect formation. Both the depth and amount of damage created are crucial to the success of the Si implantation. 5 refs., 1 tab., 2 figs.

  12. Metal ion concentrations in body fluids after implantation of hip replacements with metal-on-metal bearing--systematic review of clinical and epidemiological studies.

    Directory of Open Access Journals (Sweden)

    Albrecht Hartmann

    Full Text Available INTRODUCTION: The use of metal-on-metal (MoM total hip arthroplasty (THA increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. OBJECTIVE: To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. METHODS: Systematic review of clinical trials (RCTs and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor, patient characteristics as well as study quality characteristics (secondary explanatory factors. RESULTS: Overall, 104 studies (11 RCTs, 93 epidemiological studies totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L. Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. DISCUSSION: Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed "time out" for stemmed large-head MoM-THA and recommend a restricted

  13. Ab initio studies on the adsorption and implantation of Al and Fe to nitride materials

    Energy Technology Data Exchange (ETDEWEB)

    Riedl, H., E-mail: helmut.riedl@tuwien.ac.at [Christian Doppler Laboratory for Application Oriented Coating Development at the Institute of Materials Science and Technology, TU Wien, A-1040 Wien (Austria); Zálešák, J. [Erich Schmid Institute for Materials Science, Austria Academy of Science, A-8700 Leoben (Austria); Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben (Austria); Arndt, M. [Oerlikon Balzers, Oerlikon Surface Solutions AG, LI-9496 Balzers (Liechtenstein); Polcik, P. [Plansee Composite Materials GmbH, D-86983 Lechbruck am See (Germany); Holec, D. [Christian Doppler Laboratory for Application Oriented Coating Development at the Institute of Materials Science and Technology, TU Wien, A-1040 Wien (Austria); Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben (Austria); Mayrhofer, P. H. [Christian Doppler Laboratory for Application Oriented Coating Development at the Institute of Materials Science and Technology, TU Wien, A-1040 Wien (Austria); Institute of Materials Science and Technology, TU Wien, A-1040 Vienna (Austria)

    2015-09-28

    The formation of transfer material products on coated cutting and forming tools is a major failure mechanism leading to various sorts of wear. To describe the atomistic processes behind the formation of transfer materials, we use ab initio to study the adsorption energy as well as the implantation barrier of Al and Fe atoms for (001)-oriented surfaces of TiN, Ti{sub 0.50}Al{sub 0.50}N, Ti{sub 0.90}Si{sub 0.10}N, CrN, and Cr{sub 0.90}Si{sub 0.10}N. The interactions between additional atoms and nitride-surfaces are described for pure adhesion, considering no additional stresses, and for the implantation barrier. The latter, we simplified to the stress required to implant Al and Fe into sub-surface regions of the nitride material. The adsorption energies exhibit pronounced extrema at high-symmetry positions and are generally highest at nitrogen sites. Here, the binary nitrides are comparable to their ternary counterparts and the average adhesive energy is higher (more negative) on CrN than TiN based systems. Contrary, the implantation barrier for Al and Fe atoms is higher for the ternary systems Ti{sub 0.50}Al{sub 0.50}N, Ti{sub 0.90}Si{sub 0.10}N, and Cr{sub 0.90}Si{sub 0.10}N than for their binary counterparts TiN and CrN. Based on our results, we can conclude that TiN based systems outperform CrN based systems with respect to pure adhesion, while the Si-containing ternaries exhibit higher implantation barriers for Al and Fe atoms. The data obtained are important to understand the atomistic interaction of metal atoms with nitride-based materials, which is valid not just for machining operations but also for any combination such as interfaces between coatings and substrates or multilayer and phase arrangements themselves.

  14. The DAIR (debridement, antibiotics and implant retention) procedure for infected total knee replacement – a literature review

    Science.gov (United States)

    Qasim, Sultan Naseer; Swann, Andrew; Ashford, Robert

    2017-01-01

    Prosthetic joint infection (PJI) is a devastating complication in total knee arthroplasty (TKA) and third most common cause of revision of TKA with significant morbidity and surgical challenges. Treatment options include non-operative measures with long term antibiotic suppression, debridement and implant retention (DAIR), one- or two-stage revision arthroplasty, arthrodesis and amputation. Implant retention without infection is ideal and DAIR has been reported to have variable success rates depending on patient factors, duration of infection, infecting micro-organisms, choice of procedure, single or multiple debridement procedures, arthroscopic or open, antibiotic choice and duration of antibiotic use. We present a thorough literature review of DAIR for infected TKA. The important factors contributing to failure are presence of sinus, immunocompromised patient, delay between onset of infection and debridement procedure, Staphylococcal infection in particular Meticillin Resistant Staphylococcal aureus, multiple debridement procedures, retention of exchangeable components and short antibiotic duration. In conclusion DAIR can be successful procedure to eradicate infection in TKA in selective patients with factors contributing to failure taken into account. PMID:28074774

  15. Optimization of Cell Adhesion on Mg Based Implant Materials by Pre-Incubation under Cell Culture Conditions

    Directory of Open Access Journals (Sweden)

    Regine Willumeit

    2014-05-01

    Full Text Available Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture.

  16. Magnetron Sputtering a New Fabrication Method of Iron Based Biodegradable Implant Materials

    Directory of Open Access Journals (Sweden)

    Till Jurgeleit

    2015-01-01

    Full Text Available It was shown in the previous decade that pure-iron has a large potential as a biodegradable medical implant material. It is necessary to tailor the material properties according to the intended use of the device. It is of great interest to investigate not only the influence of processing on the material properties but also alternative fabrication methods. In this work for the first time magnetron sputtering in combination with UV lithography was used to fabricate free standing, patterned pure-iron thick films. For the intended use as biodegradable implant material free standing thick films were characterized in terms of microstructure, degradation performance, and mechanical properties before and after various heat treatments. The influence of microstructural changes on the degradation behavior was determined by linear polarization measurements. The mechanical properties were characterized by tensile tests. Microstructure, surface, and composition were investigated by scanning transmission electron microscopy (STEM, energy dispersive X-ray spectroscopy (EDX, and X-ray diffraction (XRD measurements. The foils exhibited a preferential orientation in 110 direction and a fine grained structure. Furthermore they showed a higher strength compared to cast iron and corrosion rates in the range of 0.1 mm/year. Their mechanical properties were tuned by grain coarsening resulting in a slight increase of the degradation rate.

  17. ERD measurement of D-H replacement in D-implanted oxide ceramics exposed to H 2O vapor at room temperature

    Science.gov (United States)

    Morita, Kenji; Tsuchiya, Bun; Nagata, Shinji; Katahira, Koji

    2006-08-01

    The speed of D-H replacement in D-implanted BaCe1-XYXO3-δ and SrCe1-XYbXO3-δ, exposed to H2O vapor at room temperature has been studied as a function of X by use of the ERD technique with MeV He+ ion beam. The decay curve of D and growth curve of H in the specimens have been measured as a function of exposure time, and the decay constants of D, namely the D-H replacement speeds, have been obtained from the experimental curves. It is found for both specimens that the decay constants of D, proportional to the absorption coefficient and the molecular formation coefficient of HD, increases and then after a maximum at X = 0.05-0.10 decreases as X increases and the absolute experimental values for BaCe1-XYXO3-δ are larger by an order of magnitude than those of SrCe1-XYbXO3-δ.

  18. Surface modification of traditional and bioresorbable metallic implant materials for improved biocompatibility

    Science.gov (United States)

    Walker, Emily K.

    Due to their strength, elasticity, and durability, a variety of metal alloys are commonly used in medical implants. Traditionally, corrosion-resistant metals have been preferred. These permanent materials can cause negative systemic and local tissue effects in the long-term. Permanent stenting can lead to late-stent thrombosis and in-stent restenosis. Metallic pins and screws for fracture fixation can corrode and fail, cause loss of bone mass, and contribute to inflammation and pain at the implant site, requiring reintervention. Corrodible metallic implants have the potential to prevent many of these complications by providing transient support to the affected tissue, dissolving at a rate congruent with the healing of the tissue. Alloys of iron and manganese (FeMn) exhibit similar fatigue strength, toughness, and elasticity compared with 316L stainless steel, making them very attractive candidates for bioresorbable stents and temporary fracture fixation devices. Much attention in recent years has been given to creating alloys with ideal mechanical properties for various applications. Little work has been done on determining the blood compatibility of these materials or on examining how their surfaces can be improved to improve cell adhesion, however. We examined thethrombogenic response of blood exposed to various resorbable ferrous stent materials through contact with porcine blood. The resorbable materials induced comparable or lower levels of several coagulation factors compared with 316L stainless steel. Little platelet adhesion was observed on any of the tested materials. Endothelialization is an important process after the implantation of a vascular stent, as it prevents damage to the vessel wall that can accelerate neointimal hyperplasia. Micromotion can lead to the formation of fibrous tissue surrounding an orthopedic implant, loosening, and ultimately failure of the implant. Nanoscale features were created on the surfaces of noble metal coatings, silicon

  19. Co-implantation of carbon and nitrogen into silicon dioxide for synthesis of carbon nitride materials

    CERN Document Server

    Huang, M B; Nuesca, G; Moore, R

    2002-01-01

    Materials synthesis of carbon nitride has been attempted with co-implantation of carbon and nitrogen into thermally grown SiO sub 2. Following implantation of C and N ions to doses of 10 sup 1 sup 7 cm sup - sup 2 , thermal annealing of the implanted SiO sub 2 sample was conducted at 1000 degree sign C in an N sub 2 ambient. As evidenced in Fourier transform infrared measurements and X-ray photoelectron spectroscopy, different bonding configurations between C and N, including C-N single bonds, C=N double bonds and C=N triple bonds, were found to develop in the SiO sub 2 film after annealing. Chemical composition profiles obtained with secondary ion mass spectroscopy were correlated with the depth information of the chemical shifts of N 1s core-level electrons, allowing us to examine the formation of C-N bonding for different atomic concentration ratios between N and C. X-ray diffraction and transmission electron microscopy showed no sign of the formation of crystalline C sub 3 N sub 4 precipitates in the SiO ...

  20. Use of bovine pericardium as a wrapping material for hydroxyapatite orbital implants

    Science.gov (United States)

    Gupta, M; Puri, P; Rennie, I G

    2002-01-01

    Aim: To present the results of 27 patients who had enucleation for malignant melanoma of the choroid with hydroxyapatite implant wrapped in bovine pericardium. Method: A retrospective study was performed on 27 patients, 12 males and 15 females, who had enucleation as a primary treatment for their choroidal melanomas. The patients were followed up at 1 week, 1 month, 3 months, and then every 6 months. A conformer was fitted at 1 week and an artificial eye at 1 month. The average follow up was 1.7 years. Results: No patient had extrusion of the implant. One patient needed repair of the wound, two patients required a lateral tarsal strip, and one patient developed a conjunctival granuloma, which did not need excision. In one patient there was shallowing of the inferior fornix. The cosmetic results and ocular movement were satisfactory in all but one patient. Conclusion: Use of bovine pericardium as wrapping material for the hydroxyapatite implants has shown promising results with minimal extrusion rates providing an effective alternative for sclera, eliminating the potential risks of CJD. PMID:11864885

  1. Cathodic Polarization Coats Titanium Based Implant Materials with Enamel Matrix Derivate (EMD

    Directory of Open Access Journals (Sweden)

    Matthias J. Frank

    2014-03-01

    Full Text Available The idea of a bioactive surface coating that enhances bone healing and bone growth is a strong focus of on-going research for bone implant materials. Enamel matrix derivate (EMD is well documented to support bone regeneration and activates growth of mesenchymal tissues. Thus, it is a prime candidate for coating of existing implant surfaces. The aim of this study was to show that cathodic polarization can be used for coating commercially available implant surfaces with an immobilized but functional and bio-available surface layer of EMD. After coating, XPS revealed EMD-related bindings on the surface while SIMS showed incorporation of EMD into the surface. The hydride layer of the original surface could be activated for coating in an integrated one-step process that did not require any pre-treatment of the surface. SEM images showed nano-spheres and nano-rods on coated surfaces that were EMD-related. Moreover, the surface roughness remained unchanged after coating, as it was shown by optical profilometry. The mass peaks observed in the matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS analysis confirmed the integrity of EMD after coating. Assessment of the bioavailability suggested that the modified surfaces were active for osteoblast like MC3M3-E1 cells in showing enhanced Coll-1 gene expression and ALP activity.

  2. Biocompatible medical implant materials with binding sites for a biodegradable drug-delivery system

    Directory of Open Access Journals (Sweden)

    Al-Dubai H

    2011-10-01

    Full Text Available Haifa Al-Dubai1, Gisela Pittner1, Fritz Pittner1, Franz Gabor21Max F Perutz Laboratories, Department of Biochemistry, University of Vienna, Vienna, Austria; 2Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Vienna, AustriaAbstract: Feasibility studies have been carried out for development of a biocompatible coating of medical implant materials allowing the binding of biodegradable drug-delivery systems in a way that their reloading might be possible. These novel coatings, able to bind biodegradable nanoparticles, may serve in the long run as drug carriers to mediate local pharmacological activity. After biodegradation of the nanoparticles, the binding sites could be reloaded with fresh drug-delivering particles. As a suitable receptor system for the nanoparticles, antibodies are anchored. The design of the receptor is of great importance as any bio- or chemorecognitive interaction with other components circulating in the blood has to be avoided. Furthermore, the binding between receptor and the particles has to be strong enough to keep them tightly bound during their lifetime, but on the other hand allow reloading after final degradation of the particles. The nanoparticles suggested as a drug-delivery system for medical implants can be loaded with different pharmaceuticals such as antibiotics, growth factors, or immunosuppressives. This concept may enable the changing of medication, even after implantation of the medical device, if afforded by patients’ needs.Keywords: antibody immobilization, biocompatible coating, chitosan nanoparticles, drug targeting, medical device

  3. Ulnar head replacement.

    Science.gov (United States)

    Herbert, Timothy J; van Schoonhoven, Joerg

    2007-03-01

    Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioulnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the ulnar head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone ulnar head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert ulnar head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after ulnar head excision and that the materials (ceramic head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an ulnar head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for ulnar head replacement and details the surgical procedure, rehabilitation, and likely outcomes.

  4. Optimal implantation depth and adherence to guidelines on permanent pacing to improve the results of transcatheter aortic valve replacement with the medtronic corevalve system: The CoreValve prospective, international, post-market ADVANCE-II study

    NARCIS (Netherlands)

    A.S. Petronio (Anna S.); J.-M. Sinning (Jan-Malte); N.M. van Mieghem (Nicolas); G. Zucchelli (Giulio); G. Nickenig (Georg); R. Bekeredjian (Raffi); B. Bosmans; F. Bedogni (Francesco); M. Branny (Marian); K. Stangl (Karl); J. Kovac (Jan); M. Schiltgen (Molly); S. Kraus (Stacia); P.P.T. de Jaegere (Peter)

    2015-01-01

    textabstractObjectives The aim of the CoreValve prospective, international, post-market ADVANCE-II study was to define the rates of conduction disturbances and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement with the Medtronic CoreValve System (Minneapolis, Minnes

  5. Optimal implantation depth and adherence to guidelines on permanent pacing to improve the results of transcatheter aortic valve replacement with the medtronic corevalve system: The CoreValve prospective, international, post-market ADVANCE-II study

    NARCIS (Netherlands)

    A.S. Petronio (Anna S.); J.-M. Sinning (Jan-Malte); N.M. van Mieghem (Nicolas); G. Zucchelli (Giulio); G. Nickenig (Georg); R. Bekeredjian (Raffi); B. Bosmans; F. Bedogni (Francesco); M. Branny (Marian); K. Stangl (Karl); J. Kovac (Jan); M. Schiltgen (Molly); S. Kraus (Stacia); P.P.T. de Jaegere (Peter)

    2015-01-01

    textabstractObjectives The aim of the CoreValve prospective, international, post-market ADVANCE-II study was to define the rates of conduction disturbances and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement with the Medtronic CoreValve System (Minneapolis, Minnes

  6. [Growth behavior of spiral ganglion explants on cochlear implant electrodes and their materials].

    Science.gov (United States)

    Hansen, S; Mlynski, R; Volkenstein, S; Stark, T; Schwaab, M; Dazert, S; Brors, D

    2009-04-01

    With the increasing use of cochlear implants (CIs), the insertion of alloplastic material into the inner ear is nowadays an established treatment for severe to profound hearing loss in children and adults. Beyond its widespread use, the biocompatibility of the CI electrode and its interaction with the neural structures of the cochlea is not yet established. To investigate the survival and growth behavior of spiral ganglion neurons on different CI materials, spiral ganglion explants from newborn rats were cultured on silicone and platinum, on a surface combination of silicone and platinum, and, finally, on a CI electrode. The results of this study indicate that the growth of spiral ganglion neurons in vitro is strongly influenced by the different materials and their arrangement, with platinum exhibiting the highest degree of biocompatibility with respect to neurite extension. Level differences in the surface structure between silicone and platinum lead to inhibition of neurite outgrowth. Furthermore, the culturing of spiral ganglion explants on a CI electrode leads to neurite sprouting toward the electrodes made of platinum. The biocompatibility of CI materials with spiral ganglion neurons was shown in this study, but it differs with different CI materials. Besides the material itself, the arrangement of the materials can affect the neurite extension.

  7. An investigation on the use of tincal ore waste, fly ash, and coal bottom ash as Portland cement replacement materials

    Energy Technology Data Exchange (ETDEWEB)

    Kula, I.; Olgun, A.; Sevinc, V.; Erdogan, Y. [Dumlupinar University, Kutahya (Turkey). Dept. of Chemistry

    2002-02-01

    The possibility of using tincal ore waste (TW), coal bottom ash (BA), and fly ash (FA) as partial replacement in concrete was examined through a number of tests. The properties examined include setting time, compressive strength, mortar expansion, water consistency of mortar, and microstructure. The results showed that compressive strength of all specimens containing 1 wt.% of TW was higher than that of the control at the 28th day of curing. At 90 days, the contribution to strength by BA + TW and FA + TW was higher than in the concrete-prepared equivalent TW beyond 3 wt.% of Portland cement (PC) replacement. With the replacement of 3-5 wt.% of PC by TW, the compressive strength of the concrete decreased compared to control concrete. However, the values obtained are within the limit of Turkish Standards. Adding BA or FA with TW improved the performance relative to TW replacement only. Increasing replacement of TW gives rise to a higher setting time. As a result. TW, BA, and FA samples may be used as cementitious materials.

  8. The potential role of polymethyl methacrylate as a new packaging material for the implantable medical device in the bladder.

    Science.gov (United States)

    Kim, Su Jin; Choi, Bumkyoo; Kim, Kang Sup; Bae, Woong Jin; Hong, Sung Hoo; Lee, Ji Youl; Hwang, Tae-Kon; Kim, Sae Woong

    2015-01-01

    Polydimethylsiloxane (PDMS) is used in implantable medical devices; however, PDMS is not a completely biocompatible material for electronic medical devices in the bladder. To identify novel biocompatible materials for intravesical implanted medical devices, we evaluated the biocompatibility of polymethyl methacrylate (PMMA) by analyzing changes in the levels of macrophages, macrophage migratory inhibitory factor (MIF), and inflammatory cytokines in the bladder. A ball-shaped metal coated with PMMA or PDMS was implanted into the bladders of rats, and after intravesical implantation, the inflammatory changes induced by the foreign body reaction were evaluated. In the early period after implantation, increased macrophage activity and MIF in the urothelium of the bladder were observed. However, significantly decreased macrophage activity and MIF in the bladder were observed after implantation with PMMA- or PDMS-coated metal in the later period. In addition, significantly decreased inflammatory cytokines such as IL-1β, IL-6, and TNF-α were observed with time. Based on these results, we suggest that MIF plays a role in the foreign body reaction and in the biocompatible packaging with PMMA for the implanted medical devices in the bladder.

  9. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Science.gov (United States)

    Qamheya, Ala Hassan A.; Yeniyol, Sinem; Arısan, Volkan

    2015-01-01

    Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC) material in teeth construction to rehabilitate a complete denture wearer patient. PMID:26557392

  10. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Directory of Open Access Journals (Sweden)

    Ala Hassan A. Qamheya

    2015-01-01

    Full Text Available Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC material in teeth construction to rehabilitate a complete denture wearer patient.

  11. Soft tissue integration versus early biofilm formation on different dental implant materials

    NARCIS (Netherlands)

    Zhao, Bingran; van der Mei, Henderina; Subbiahdoss, Guruprakash; de Vries, Joop; Rustema-Abbing, Minie; Kuijer, Roel; Busscher, Henk J.; Qu-Ren, Yijin

    2014-01-01

    OBJECTIVE: Dental implants anchor in bone through a tight fit and osseo-integratable properties of the implant surfaces, while a protective soft tissue seal around the implants neck is needed to prevent bacterial destruction of the bone-implant interface. This tissue seal needs to form in the unster

  12. Diagnostic Imaging for Dental Implant Therapy

    Directory of Open Access Journals (Sweden)

    Aishwarya Nagarajan

    2014-01-01

    Full Text Available Dental implant is a device made of alloplastic (foreign material implanted into the jaw bone beneath the mucosal layer to support a fixed or removable dental prosthesis. Dental implants are gaining immense popularity and wide acceptance because they not only replace lost teeth but also provide permanent restorations that do not interfere with oral function or speech or compromise the self-esteem of a patient. Appropriate treatment planning for replacement of lost teeth is required and imaging plays a pivotal role to ensure a satisfactory outcome. The development of pre-surgical imaging techniques and surgical templates helps the dentist place the implants with relative ease. This article focuses on various types of imaging modalities that have a pivotal role in implant therapy.

  13. Surface roughness and adaptation of different materials to secure implant attachment housings.

    Science.gov (United States)

    Ozkir, Serhat Emre; Yilmaz, Burak; Kurkcuoglu, Isin; Culhaoglu, Ahmet; Unal, Server Mutluay

    2017-01-01

    Various materials are available to secure implant attachment housings in overdentures. Surface roughness and the adaptation of these materials to the denture base and the housings may increase the microcracks and bacterial adhesion at the interfaces in the long term. The surface characteristics of the interface between the denture base orientation material and the attachment housing have not been extensively studied. The purpose of this in vitro study was to evaluate the surface roughness and the adaptation of 5 different housing orientation materials to the housings and the denture base. Fifty-five poly(methyl methacrylate) (PMMA) specimens (15 mm in diameter and 4 mm in height) were prepared with a clearance inside to allow the insertion of overdenture housings. Five different materials were used for housing orientation (Quick Up, Ufi Gel Hard, Tokuyama Rebase II Fast, Meliodent, and Paladent). The specimens were thermocycled 5000 times between 5°C and 55°C. The surface roughness (Ra values) of the specimens was measured with a noncontact profilometer. Scanning electron images were made in order to inspect the PMMA-orientation material-housing interfaces. The Kruskal-Wallis test was used to investigate the differences between the surface roughness values of the orientation materials, and the Iman-Conover test was used for pairwise comparisons (α=.05). The surface roughness values significantly differed between Quick up and Ufi Gel orientation materials only, and Quick up had smaller surface roughness values than Ufi Gel (P=.009). Microcracks were observed among the groups only at the junction of the orientation material and the housing after thermocycling. Ufi Gel Hard showed the roughest surfaces around the overdenture attachment housings. The adaptation between the orientation material and the housing may deteriorate, and increased surface roughness and microcrack formation may be seen around the housings. Copyright © 2016 Editorial Council for the

  14. Surface properties of titanium and zirconia dental implant materials and their effect on bacterial adhesion.

    Science.gov (United States)

    Al-Radha, Afya Sahib Diab; Dymock, David; Younes, Charles; O'Sullivan, Dominic

    2012-02-01

    Zirconia ceramic material has been widely used in implant dentistry. In this in vitro study the physiochemical properties of titanium and zirconia materials were investigated and the affinity of different bacteria to different materials was compared. Disc samples with different surface states were used: polished partially stabilized zirconia (PZ), titanium blasted with zirconia (TBZ), titanium blasted with zirconia then acid etched (TBZA), and polished titanium (PT) as a control. Surface topography was examined using scanning electron microscopy and profilometry. Contact angle, surface free energy (SFE), surface microhardness and chemical composition were determined. Disc samples were separately incubated with Streptococcus mitis and Prevotella nigrescens, either with or without pre-coating with human saliva, for 6h and the surface area covered by bacteria was calculated from fluorescence microscope images. PZ and TBZ exhibited lower surface free energy and lesser surface wettability than PT. Also, PZ and TBZ surfaces showed lower percentage of bacterial adhesion compared with control PT surface. The zirconia material and titanium blasted with zirconia surface (TBZ surface) showed superior effect to titanium material in reducing the adhesion of the experimented bacteria especially after coating with saliva pellicle. Modifying titanium with zirconia lead to have the same surface properties of pure zirconia material in reducing bacterial adhesion. SFE appears to be the most important factors that determine initial bacterial adhesion to smooth surface. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. An integrated approach of topology optimized design and selective laser melting process for titanium implants materials.

    Science.gov (United States)

    Xiao, Dongming; Yang, Yongqiang; Su, Xubin; Wang, Di; Sun, Jianfeng

    2013-01-01

    The load-bearing bone implants materials should have sufficient stiffness and large porosity, which are interacted since larger porosity causes lower mechanical properties. This paper is to seek the maximum stiffness architecture with the constraint of specific volume fraction by topology optimization approach, that is, maximum porosity can be achieved with predefine stiffness properties. The effective elastic modulus of conventional cubic and topology optimized scaffolds were calculated using finite element analysis (FEA) method; also, some specimens with different porosities of 41.1%, 50.3%, 60.2% and 70.7% respectively were fabricated by Selective Laser Melting (SLM) process and were tested by compression test. Results showed that the computational effective elastic modulus of optimized scaffolds was approximately 13% higher than cubic scaffolds, the experimental stiffness values were reduced by 76% than the computational ones. The combination of topology optimization approach and SLM process would be available for development of titanium implants materials in consideration of both porosity and mechanical stiffness.

  16. Implante percutâneo de valva aórtica: mito ou realidade? Percutaneous aortic aortic valve replacement: myth or reality?

    Directory of Open Access Journals (Sweden)

    Eduardo Keller Saadi

    2008-03-01

    Full Text Available A substituição valvar por prótese metálica ou biológica com o auxílio de circulação extracorpórea é o procedimento padrão-ouro para o tratamento da estenose aórtica calcificada. Embora os resultados sejam excelentes com a cirurgia convencional, alguns pacientes com idade avançada, doenças associadas, reoperações e disfunção ventricular esquerda grave apresentam alto risco cirúrgico. Nos últimos anos, técnicas de tratamento percutâneo foram desenvolvidas. A presente revisão tem por objetivo analisar a literatura desde o desenvolvimento experimental até a aplicação clínica desta nova modalidade de tratamento para pacientes com estenose aórtica grave e alto risco cirúrgico. O implante percutâneo de valva aórtica hoje vem sendo realizado por alguns centros e o cirurgião cardiovascular envolvido no tratamento das doenças valvares deve fazer parte deste desenvolvimento.Aortic valve replacement with mechanical or biological prosthesis with extracorporeal circulation is the gold-standard for the treatment of calcific aortic stenosis. Although the results are excellent with the conventional approach some elderly patients, with multiple high-risk comorbid conditions, reoperations and severe left ventricular dysfunction have high surgical risk. During the last years percutaneous techniques have been developed. The present study aim to analyse the literature, since the experimental development untill clinical application of this novel treatment in patients with high surgical risk aortic stenosis. Percutaneous implantation of aortic valve prosthesis is beeing done in some centers and the cardiovascular surgeon that treats valve disease should be involved in this development.

  17. Surface coatings for improvement of bone cell materials and antimicrobial activities of Ti implants.

    Science.gov (United States)

    Das, Kakoli; Bose, Susmita; Bandyopadhyay, Amit; Karandikar, Balu; Gibbins, Bruce L

    2008-11-01

    Ti surface was modified to simultaneously improve bone cell materials and antimicrobial activities. Titanium surface was first anodized in sodium fluoride and sulfuric acid electrolytic solution to form titania nanotube on the surface to improve the biocompatibility of the surface. Silver was electrodeposited on the titania nanotube surface at 5 V. Silver added titania nanotube surface was tested for compatibility with bone-cell materials interactions using human osteoblast bone cells. The antibacterial effect was studied using Pseudomonas aeruginosa. Our results show that silver-treated titania nanotube surface may provide antibacterial properties to prevent implants against postoperative infections without interference to the attachment and proliferation of bone tissue on titanium, which is commonly used in dental and orthopedic surgical procedures.

  18. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    Science.gov (United States)

    Alikhasi, Marzieh; Siadat, Hakimeh; Kharazifard, Mohammad Javad

    2015-01-01

    Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl siloxane (PVS) impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM). Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM). These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05. Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (Ptray technique showed less angular displacement with the use of PVS impression material. Detail reproduction accuracy was the same in all the groups (P>0.05). Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction. PMID:27252761

  19. Adverse sequelae following revision of a total hip replacement for a fractured ceramic component: case report

    Directory of Open Access Journals (Sweden)

    Lee Ling Hong

    2015-01-01

    Full Text Available Revision total hip replacement following a fractured ceramic bearing component presents a challenge in the choice of the new bearing implant. A femoral head made of equal or harder material should be implanted to prevent catastrophic wear. Despite this, patients and surgeons must be wary of potential complications.

  20. Multiscale Homogenization Theory: An Analysis Tool for Revealing Mechanical Design Principles in Bone and Bone Replacement Materials

    Science.gov (United States)

    Hellmich, Christian; Fritsch, Andreas; Dormieux, Luc

    Biomimetics deals with the application of nature-made "design solutions" to the realm of engineering. In the quest to understand mechanical implications of structural hierarchies found in biological materials, multiscale mechanics may hold the key to understand "building plans" inherent to entire material classes, here bone and bone replacement materials. Analyzing a multitude of biophysical hierarchical and biomechanical experiments through homogenization theories for upscaling stiffness and strength properties reveals the following design principles: The elementary component "collagen" induces, right at the nanolevel, the mechanical anisotropy of bone materials, which is amplified by fibrillar collagen-based structures at the 100-nm scale, and by pores in the micrometer-to-millimeter regime. Hydroxyapatite minerals are poorly organized, and provide stiffness and strength in a quasi-brittle manner. Water layers between hydroxyapatite crystals govern the inelastic behavior of the nanocomposite, unless the "collagen reinforcement" breaks. Bone replacement materials should mimic these "microstructural mechanics" features as closely as possible if an imitation of the natural form of bone is desired (Gebeshuber et al., Adv Mater Res 74:265-268, 2009).

  1. Early staphylococcal biofilm formation on solid orthopaedic implant materials: in vitro study.

    Directory of Open Access Journals (Sweden)

    Hironobu Koseki

    Full Text Available Biofilms forming on the surface of biomaterials can cause intractable implant-related infections. Bacterial adherence and early biofilm formation are influenced by the type of biomaterial used and the physical characteristics of implant surface. In this in vitro research, we evaluated the ability of Staphylococcus epidermidis, the main pathogen in implant-related infections, to form biofilms on the surface of the solid orthopaedic biomaterials, oxidized zirconium-niobium alloy, cobalt-chromium-molybdenum alloy (Co-Cr-Mo, titanium alloy (Ti-6Al-4V, commercially pure titanium (cp-Ti and stainless steel. A bacterial suspension of Staphylococcus epidermidis strain RP62A (ATCC35984 was added to the surface of specimens and incubated. The stained biofilms were imaged with a digital optical microscope and the biofilm coverage rate (BCR was calculated. The total amount of biofilm was determined with the crystal violet assay and the number of viable cells in the biofilm was counted using the plate count method. The BCR of all the biomaterials rose in proportion to culture duration. After culturing for 2-4 hours, the BCR was similar for all materials. However, after culturing for 6 hours, the BCR for Co-Cr-Mo alloy was significantly lower than for Ti-6Al-4V, cp-Ti and stainless steel (P0.05. These results suggest that surface properties, such as hydrophobicity or the low surface free energy of Co-Cr-Mo, may have some influence in inhibiting or delaying the two-dimensional expansion of biofilm on surfaces with a similar degree of smoothness.

  2. Properties of Frankfurter-type Sausages with Pork Back-fat Replaced with Bovine Heart Surimi-like Materials

    Science.gov (United States)

    Seo, Jin-Kyu; Yum, Hyeon-Woong; Kim, Gap-Don; Jeong, Jin-Yeon; Yang, Han-Sul

    2016-01-01

    This study investigates the effect of bovine heart surimi-like material (BHSM) used as a back fat replacer, on the physicochemical and sensory characteristics of frankfurter-type sausages. Frankfurter-type sausage with added BHSM had a higher moisture content and lower fat content than the control. In addition, the samples with added BHSM had higher pH, cooking loss and 2-thiobarbituric acid-reactive substance (TBARS) value and lower water exudation than the control. The sausage formulation with 40% BHSM was more effective in delaying lipid oxidation without affecting cooking loss compared to the 60% BHSM treatment sample. Results showed that hardness values increased upon replacement with BHSM, and sausages manufactured with 40% BHSM had higher lightness and lower redness values. Panelists found there were no differences in color, odor, and tenderness scores and the overall acceptability score found that treatment samples containing 20% and 40% BHSM were preferable to the control after storage for 14 d. These results indicate that fat replacement with BHSM was beneficial to the quality of frankfurter-type sausages, and acceptable reduced-fat products can be produced when back fat is replaced with up to 40% BHSM. PMID:27621694

  3. Recent patents and designs on hip replacement prostheses.

    Science.gov (United States)

    Derar, H; Shahinpoor, M

    2015-01-01

    Hip replacement surgery has gone through tremendous evolution since the first procedure in 1840. In the past five decades the advances that have been made in technology, advanced and smart materials innovations, surgical techniques, robotic surgery and methods of fixations and sterilization, facilitated hip implants that undergo multiple design revolutions seeking the least problematic implants and a longer survivorship. Hip surgery has become a solution for many in need of hip joint remedy and replacement across the globe. Nevertheless, there are still long-term problems that are essential to search and resolve to find the optimum implant. This paper reviews several recent patents on hip replacement surgery. The patents present various designs of prostheses, different materials as well as methods of fixation. Each of the patents presents a new design as a solution to different issues ranging from the longevity of the hip prostheses to discomfort and inconvenience experienced by patients in the long-term.

  4. Nanoparticulate zinc oxide as a coating material for orthopedic and dental implants.

    Science.gov (United States)

    Memarzadeh, Kaveh; Sharili, Amir S; Huang, Jie; Rawlinson, Simon C F; Allaker, Robert P

    2015-03-01

    Orthopedic and dental implants are prone to infection. In this study, we describe a novel system using zinc oxide nanoparticles (nZnO) as a coating material to inhibit bacterial adhesion and promote osteoblast growth. Electrohydrodynamic atomisation (EHDA) was employed to deposit mixtures of nZnO and nanohydroxyapatite (nHA) onto the surface of glass substrates. Nano-coated substrates were exposed to Staphylococcus aureus suspended in buffered saline or bovine serum to determine antimicrobial activity. Our results indicate that 100% nZnO and 75% nZnO/25% nHA composite-coated substrates have significant antimicrobial activity. Furthermore, osteoblast function was explored by exposing cells to nZnO. UMR-106 cells exposed to nZnO supernatants showed minimal toxicity. Similarly, MG-63 cells cultured on nZnO substrates did not show release of TNF-α and IL-6 cytokines. These results were reinforced by both proliferation and differentiation studies which revealed that a substrate coated with exclusively nZnO is more efficient than composite surface coatings. Finally, electron and light microscopy, together with immunofluorescence staining, revealed that all cell types tested, including human mesenchymal cell (hMSC), were able to maintain normal cell morphology when adhered onto the surface of the nano-coated substrates. Collectively, these findings indicate that nZnO can, on its own, provide an optimal coating for future bone implants that are both antimicrobial and biocompatible.

  5. Applications of ions produced by low intensity repetitive laser pulses for implantation into semiconductor materials

    Science.gov (United States)

    Wołowski, J.; Badziak, J.; Czarnecka, A.; Parys, P.; Pisarek, M.; Rosinski, M.; Turan, R.; Yerci, S.

    This work reports experiment concerning specific applications of implantation of laser-produced ions for production of semiconductor nanocrystals. The investigation was carried out in the IPPLM within the EC STREP `SEMINANO' project. A repetitive pulse laser system of parameters: energy up to 0.8 J in a 3.5 ns-pulse, wavelength of 1.06 μ m, repetition rate of up to 10 Hz, has been employed in these investigations. The characterisation of laser-produced ions was performed with the use of `time-of-flight' ion diagnostics simultaneously with other diagnostic methods in dependence on laser pulse parameters, illumination geometry and target material. The properties of laser-implanted and modified SiO2 layers on sample surface were characterised with the use of different methods (XPS + ASD, Raman spectroscopy, PL spectroscopy) at the Middle East Technological University in Ankara and at the Warsaw University of Technology. The production of the Ge nanocrystallites has been demonstrated for annealed samples prepared in different experimental conditions.

  6. How to Study Biofilms after Microbial Colonization of Materials Used in Orthopaedic Implants

    Science.gov (United States)

    Drago, Lorenzo; Agrappi, Serse; Bortolin, Monica; Toscano, Marco; Romanò, Carlo Luca; De Vecchi, Elena

    2016-01-01

    Over the years, various techniques have been proposed for the quantitative evaluation of microbial biofilms. Spectrophotometry after crystal violet staining is a widespread method for biofilm evaluation, but several data indicate that it does not guarantee a good specificity, although it is rather easy to use and cost saving. Confocal laser microscopy is one of the most sensitive and specific tools to study biofilms, and it is largely used for research. However, in some cases, no quantitative measurement of the matrix thickness or of the amount of embedded microorganisms has been performed, due to limitation in availability of dedicated software. For this reason, we have developed a protocol to evaluate the microbial biofilm formed on sandblasted titanium used for orthopaedic implants, that allows measurement of biomass volume and the amount of included cells. Results indicate good reproducibility in terms of measurement of biomass and microbial cells. Moreover, this protocol has proved to be applicable for evaluation of the efficacy of different anti-biofilm treatments used in the orthopaedic setting. Summing up, the protocol here described is a valid and inexpensive method for the study of microbial biofilm on prosthetic implant materials. PMID:26927075

  7. An exploration of plastic deformation dependence of cell viability and adhesion in metallic implant materials.

    Science.gov (United States)

    Uzer, B; Toker, S M; Cingoz, A; Bagci-Onder, T; Gerstein, G; Maier, H J; Canadinc, D

    2016-07-01

    The relationship between cell viability and adhesion behavior, and micro-deformation mechanisms was investigated on austenitic 316L stainless steel samples, which were subjected to different amounts of plastic strains (5%, 15%, 25%, 35% and 60%) to promote a variety in the slip and twin activities in the microstructure. Confocal laser scanning microscopy (CLSM) and field emission scanning electron microscopy (FESEM) revealed that cells most favored the samples with the largest plastic deformation, such that they spread more and formed significant filopodial extensions. Specifically, brain tumor cells seeded on the 35% deformed samples exhibited the best adhesion performance, where a significant slip activity was prevalent, accompanied by considerable slip-twin interactions. Furthermore, maximum viability was exhibited by the cells seeded on the 60% deformed samples, which were particularly designed in a specific geometry that could endure greater strain values. Overall, the current findings open a new venue for the production of metallic implants with enhanced biocompatibility, such that the adhesion and viability of the cells surrounding an implant can be optimized by tailoring the surface relief of the material, which is dictated by the micro-deformation mechanism activities facilitated by plastic deformation imposed by machining.

  8. Placement of replace select Ti-Unite-coated type implants using a combination of immediate and submerge techniques after tooth extraction

    Directory of Open Access Journals (Sweden)

    Coen Pramono D

    2006-06-01

    Full Text Available The high success rate of immediate implant placement both in the anterior and posterior regions were reported by many authors, therefore applying this techniques can be considered as a safe surgical procedure and minimizing the dental office visit for patient satisfaction. This paper reports the outcome of immediate placement of implants following extraction of anterior maxillary teeth. Combination technique of immediate and submerge implant placements including bone grafting procedure were used. Four implants with TiUnite surface type were placed immediately in two patients with the short-term result indicated that this technique may serve as a simple and safe procedure for immediate implant placement. It was concluded that immediate implant placement technique combined with TiUnite implant surface was successful in treating region directly after tooth extraction therefore this technique can be use as an alternative surgical method for dental implant rehabilitation.

  9. Microstructure and mechanical properties of Ti-15Zr alloy used as dental implant material.

    Science.gov (United States)

    Medvedev, Alexander E; Molotnikov, Andrey; Lapovok, Rimma; Zeller, Rolf; Berner, Simon; Habersetzer, Philippe; Dalla Torre, Florian

    2016-09-01

    Ti-Zr alloys have recently started to receive a considerable amount of attention as promising materials for dental applications. This work compares mechanical properties of a new Ti-15Zr alloy to those of commercially pure titanium Grade4 in two surface conditions - machined and modified by sand-blasting and etching (SLA). As a result of significantly smaller grain size in the initial condition (1-2µm), the strength of Ti-15Zr alloy was found to be 10-15% higher than that of Grade4 titanium without reduction in the tensile elongation or compromising the fracture toughness. The fatigue endurance limit of the alloy was increased by around 30% (560MPa vs. 435MPa and 500MPa vs. 380MPa for machined and SLA-treated surfaces, respectively). Additional implant fatigue tests showed enhanced fatigue performance of Ti-15Zr over Ti-Grade4.

  10. [In Situ Polymerization and Characterization of Hydroxyapatite/polyurethane Implanted Material].

    Science.gov (United States)

    Gu, Muqing; Xiao, Fengjuan; Liang, Ye; Yue, Lin; Li, Song; Li, Lanlan; Feng, Feifei

    2015-08-01

    In order to improve the interfacial bonding strength of hydroxyapatite/polyurethane implanted material and dispersion of hydroxyapatite in the polyurethane matrix, we in the present study synthesized nano-hydroxyapatite/polyurethane composites by in situ polymerization. We then characterized and analyzed the fracture morphology, thermal stability, glass transition temperature and mechanical properties. We seeded MG63 cells on composites to evaluate the cytocompatibility of the composites. In situ polymerization could improve the interfacial bonding strength, ameliorate dispersion of hydroxyapatite in the properties of the composites. After adding 20 wt% hydroxyapatite into the polyurethane, the thermal stability was improved and the glass transition temperatures were increased. The tensile strength and maximum elongation were 6.83 MPa and 861.17%, respectively. Compared with those of pure polyurethane the tensile strength and maximum elongation increased by 236.45% and 143.30%, respectively. The composites were helpful for cell adhesion and proliferation in cultivation.

  11. Anodized titania: Processing and characterization to improve cell-materials interactions for load bearing implants

    Science.gov (United States)

    Das, Kakoli

    The objective of this study is to investigate in vitro cell-materials interactions using human osteoblast cells on anodized titanium. Titanium is a bioinert material and, therefore, gets encapsulated after implantation into the living body by a fibrous tissue that isolates them from the surrounding tissues. In this work, bioactive nonporous and nanoporous TiO2 layers were grown on commercially pure titanium substrate by anodization process using different electrolyte solutions namely (1) H3PO 4, (2) HF and (3) H2SO4, (4) aqueous solution of citric acid, sodium fluoride and sulfuric acid. The first three electrolytes produced bioactive TiO2 films with a nonporous structure showing three distinctive surface morphologies. Nanoporous morphology was obtained on Ti-surfaces from the fourth electrolyte at 20V for 4h. Cross-sectional view of the nanoporous surface reveals titania nanotubes of length 600 nm. It was found that increasing anodization time initially increased the height of the nanotubes while maintaining the tubular array structure, but beyond 4h, growth of nanotubes decreased with a collapsed array structure. Human osteoblast (HOB) cell attachment and growth behavior were studied using an osteoprecursor cell line (OPC 1) for 3, 7 and 11 days. Colonization of the cells was noticed with distinctive cell-to-cell attachment on HF anodized surfaces. TiO2 layer grown in H2SO4 electrolyte did not show significant cell growth on the surface, and some cell death was also noticed. Good cellular adherence with extracellular matrix extensions in between the cells was noticed for samples anodized with H3PO 4 electrolyte and nanotube surface. Cell proliferation was excellent on anodized nanotube surfaces. An abundant amount of extracellular matrix (ECM) between the neighboring cells was also noticed on nanotube surfaces with filopodia extensions coming out from cells to grasp the nanoporous surface for anchorage. To better understand and compare cell-materials interactions

  12. Comparative evaluation among different materials to replace soft tissue in oral radiology studies

    Directory of Open Access Journals (Sweden)

    Maria de Paula Caldas

    2010-06-01

    Full Text Available OBJECTIVE: The aim of this study was to establish which materials afford better simulation of soft tissues in Oral Radiology studies. MATERIAL AND METHODS: The sample was composed of four materials in eleven different thicknesses to simulate the soft tissues of the face. The mean values of the relative amounts of radiographic contrast of the materials were determined and compared to a gold standard value, which was obtained from 20 patients who were referred to have periapical radiographs taken of the left mandibular molars. Data were subjected to statistical analysis with Dunnett's test (p<0.05. RESULTS: The mean value of the relative amounts of contrast encountered in the patients was 0.47, with a range between 0.36 and 0.64 for all 44 material/thickness combinations. The majority of the tested materials showed values close to those of the patients' tissues, without statistically signifcant differences among them. The values of only three materials/thickness combinations differed statistically from those of the patients' tissues. CONCLUSIONS: Based on the results of the present study, it may be concluded that except for utility wax (4 mm and 8 mm and water (4 mm, all materials tested at different thickness could be used as soft tissue substitute materials in Oral Radiology studies.

  13. Study on properties of rice husk ash and its use as cement replacement material

    Directory of Open Access Journals (Sweden)

    Ghassan Abood Habeeb

    2010-06-01

    Full Text Available This paper investigates the properties of rice husk ash (RHA produced by using a ferro-cement furnace. The effect of grinding on the particle size and the surface area was first investigated, then the XRD analysis was conducted to verify the presence of amorphous silica in the ash. Furthermore, the effect of RHA average particle size and percentage on concrete workability, fresh density, superplasticizer (SP content and the compressive strength were also investigated. Although grinding RHA would reduce its average particle size (APS, it was not the main factor controlling the surface area and it is thus resulted from RHA's multilayered, angular and microporous surface. Incorporation of RHA in concrete increased water demand. RHA concrete gave excellent improvement in strength for 10% replacement (30.8% increment compared to the control mix, and up to 20% of cement could be valuably replaced with RHA without adversely affecting the strength. Increasing RHA fineness enhanced the strength of blended concrete compared to coarser RHA and control OPC mixtures.

  14. Size- and shape-dependent foreign body immune response to materials implanted in rodents and non-human primates

    Science.gov (United States)

    Veiseh, Omid; Doloff, Joshua C.; Ma, Minglin; Vegas, Arturo J.; Tam, Hok Hei; Bader, Andrew R.; Li, Jie; Langan, Erin; Wyckoff, Jeffrey; Loo, Whitney S.; Jhunjhunwala, Siddharth; Chiu, Alan; Siebert, Sean; Tang, Katherine; Hollister-Lock, Jennifer; Aresta-Dasilva, Stephanie; Bochenek, Matthew; Mendoza-Elias, Joshua; Wang, Yong; Qi, Merigeng; Lavin, Danya M.; Chen, Michael; Dholakia, Nimit; Thakrar, Raj; Lacík, Igor; Weir, Gordon C.; Oberholzer, Jose; Greiner, Dale L.; Langer, Robert; Anderson, Daniel G.

    2015-06-01

    The efficacy of implanted biomedical devices is often compromised by host recognition and subsequent foreign body responses. Here, we demonstrate the role of the geometry of implanted materials on their biocompatibility in vivo. In rodent and non-human primate animal models, implanted spheres 1.5 mm and above in diameter across a broad spectrum of materials, including hydrogels, ceramics, metals and plastics, significantly abrogated foreign body reactions and fibrosis when compared with smaller spheres. We also show that for encapsulated rat pancreatic islet cells transplanted into streptozotocin-treated diabetic C57BL/6 mice, islets prepared in 1.5-mm alginate capsules were able to restore blood-glucose control for up to 180 days, a period more than five times longer than for transplanted grafts encapsulated within conventionally sized 0.5-mm alginate capsules. Our findings suggest that the in vivo biocompatibility of biomedical devices can be significantly improved simply by tuning their spherical dimensions.

  15. Wear and damage of articular cartilage with friction against orthopedic implant materials.

    Science.gov (United States)

    Oungoulian, Sevan R; Durney, Krista M; Jones, Brian K; Ahmad, Christopher S; Hung, Clark T; Ateshian, Gerard A

    2015-07-16

    The objective of this study was to measure the wear response of immature bovine articular cartilage tested against glass or alloys used in hemiarthroplasties. Two cobalt chromium alloys and a stainless steel alloy were selected for these investigations. The surface roughness of one of the cobalt chromium alloys was also varied within the range considered acceptable by regulatory agencies. Cartilage disks were tested in a configuration that promoted loss of interstitial fluid pressurization to accelerate conditions believed to occur in hemiarthroplasties. Results showed that considerably more damage occurred in cartilage samples tested against stainless steel (10 nm roughness) and low carbon cobalt chromium alloy (27 nm roughness) compared to glass (10 nm) and smoother low or high carbon cobalt chromium (10 nm). The two materials producing the greatest damage also exhibited higher equilibrium friction coefficients. Cartilage damage occurred primarily in the form of delamination at the interface between the superficial tangential zone and the transitional middle zone, with much less evidence of abrasive wear at the articular surface. These results suggest that cartilage damage from frictional loading occurs as a result of subsurface fatigue failure leading to the delamination. Surface chemistry and surface roughness of implant materials can have a significant influence on tissue damage, even when using materials and roughness values that satisfy regulatory requirements.

  16. Electrophoretic deposition of organic/inorganic composite coatings on metallic substrates for bone replacement applications: mechanisms and development of new bioactive materials based on polysaccharides

    OpenAIRE

    Cordero Arias, Luis Eduardo

    2015-01-01

    Regarding the need to improve the usually encountered osteointegration of metallic implants with the surrounding body tissue in bone replacement applications, bioactive organic/inorganic composite coatings on metallic substrates were developed in this work using electrophoretic deposition (EPD) as coating technology. In the present work three polysaccharides, namely alginate, chondroitin sulfate and chitosan were used as the organic part, acting as the matrix of the coating and enabling the c...

  17. Patient-related predictors of implant failure after primary total hip replacement in the initial, short- and long-terms. A nationwide Danish follow-up study including 36,984 patients

    DEFF Research Database (Denmark)

    Johnsen, S.P.; Sørensen, H.T.; Lucht, Ulf

    2006-01-01

    We examined the association between patient-related factors and the risk of initial, short- and long-term implant failure after primary total hip replacement. We used data from the Danish Hip Arthroplasty Registry between 1 January 1995 and 31 December 2002, which gave us a total of 36 984 patients....... Separate analyses were carried out for three follow-up periods: 0 to 30 days, 31 days to six months (short term), and six months to 8.6 years after primary total hip replacement (long term). The outcome measure was defined as time to failure, which included re-operation with open surgery for any reason...

  18. Replacing Noble Metals with Alternative Materials in Plasmonics and Metamaterials: how good an idea?

    CERN Document Server

    Khurgin, Jacob B

    2016-01-01

    Noble metals that currently dominate the fields of plasmonics and metamaterials suffer from large ohmic losses. New plasmonic materials, such as doped oxides and nitrides, have smaller material loss, and, using them in place of metals carries promise of reduced-loss plasmonic and metamaterial structures, with sharper resonances and higher field concentration. This promise is put to a rigorous analytical test in this work which reveals that having low material loss is not sufficient to have a reduced modal loss in plasmonic structures. To reduce the modal loss it is absolutely necessary for the plasma frequency to be significantly higher than the operational frequency. Using examples of nanoparticle plasmons and gap plasmons one comes to the conclusion that even in the mid-infrared spectrum metals continue to hold advantage over the alternative media. The new materials may still find application niche where the high absorption loss is beneficial, e.g. in medicine and thermal photovoltaics.

  19. A Review on Biodentine, a Contemporary Dentine Replacement and Repair Material

    National Research Council Canada - National Science Library

    Malkondu, Özlem; Kazandağ, Meriç Karapinar; Kazazoğlu, Ender

    2014-01-01

      Biodentine is a calcium-silicate based material that has drawn attention in recent years and has been advocated to be used in various clinical applications, such as root perforations, apexification...

  20. Study & Analysis of Knuckle Joint with the Replacement of Material by Using Teflon

    Directory of Open Access Journals (Sweden)

    Nishant Vibhav Saxena

    2015-03-01

    Full Text Available The rapid growth of technology in recent decades has led to the reduction of cost and weight of materials. The modified system has become popular in industry as well as in research. As a result, this there are reduction in accident and safety has increased. Many systems used in industries use knuckle joint which is combination of two materials: cast iron and stainless steel. Here we are proposing the modification of one of the material that is changing cast iron into a composite polymer material. The proposed system has many advantages over other system such as making the device, simpler and having maximum safety and is ecofriendly. The analysis of the system proves all the above features mention above. The reason for considering polymer is that property of polymer is mostly similar to the property of metal. Composite polymers are characterized by a high flexibility material. The revolutionary evolution in technologies in last year allowed reducing stress and strain. In the present work ANSYS 13 has been used for analysis of knuckle joint with modified material and varying loads.

  1. Comparative three-dimensional finite element analysis of implant-supported fixed complete arch mandibular prostheses in two materials.

    Science.gov (United States)

    Tribst, João Paulo Mendes; de Morais, Dayana Campanelli; Alonso, Alexandre Abhdala; Piva, Amanda Maria de Oliveira Dal; Borges, Alexandre Luis Souto

    2017-01-01

    The increase of requests for implant-supported prosthesis (ISP) with zirconia as infrastructure has attracted a lot of attention due to its esthetics, biocompatibility, and survival rate similar to metallic infrastructure. The aim of this study was to evaluate the influence of two different framework materials on stress distribution over a bone tissue-simulating material. Two ISP were modeled and divided into two infrastructure materials: titanium (Ti) and zirconia. Then, these bars were attached to a modeled jaw with polyurethane properties to simulate bone tissue. An axial load of 200 N was applied on a standardized area for both systems. Maximum principal stress (MPS) on solids and microstrain (MS) generated through the jaw were analyzed by finite element analysis. According to MS, both models showed strains on peri-implant region of the penultimate (same side of the load application) and central implants. For MPS, more stress concentration was slightly higher in the left posterior region for Ti's bar. In prosthetic fixation screws, the MPS prevailed strongly in Ti protocol, while for zirconia's bar, the cervical of the penultimate implant was the one that highlighted larger areas of possible damages. The stress generated in all constituents of the system was not significantly influenced by the framework's material. This allows suggesting that in cases without components, the use of a framework in zirconia has biomechanical behavior similar to that of a Ti bar.

  2. The Effect of abutment wall modification, filling material & copying design on retention of cement retained implant supported crown

    Directory of Open Access Journals (Sweden)

    Shima Aalaei

    2016-12-01

    Full Text Available Background and aim: Factors which can effect of tooth supported crowns are well known. On the other side, low information are existed about retention of implant supported crowns. The aim of the present study was to evaluate the effect of abutment wall modification, filling material & copying design on retention of cement retained implant supported crown. Materials and methods: In this study, 4 straight abutments were attached to their implant analogues and were embedded in the acrylic resin block. Abutments were modified to one, two, three and four walls. Then, two type copying were made: conventional and with metal extension in two screw access cavity. Access cavities were filled incompletely by three methods: copying with extension spread into the access cavity without material and conventional copying with polytetrafluoroethylene (PTFE or composite. Then cemented with temporary agent (TempBond. Required tensile force for separation of copying was measured by universal testing machine. Data were analyzed using ANOVA as statistical test. Results: About findings of this research, no significant difference were detected among two methods of filling of access cavity and engaging screw access channel (P>0.05. Four wall abutment shown significantly higher retention than the others (P<0.05 and three other abutments have no significant difference in retention. Conclusion: The type of filling material of access cavity (PTFE and composite and engaging of the copying design have no significant effects on the cemented retained of implant supported restoration but existence of all four septums increase the veneer retention significantly.

  3. The effect of fly ash and coconut fibre ash as cement replacement materials on cement paste strength

    Science.gov (United States)

    Bayuaji, R.; Kurniawan, R. W.; Yasin, A. K.; Fatoni, H. AT; Lutfi, F. M. A.

    2016-04-01

    Concrete is the backbone material in the construction field. The main concept of the concrete material is composed of a binder and filler. Cement, concrete main binder highlighted by environmentalists as one of the industry are not environmentally friendly because of the burning of cement raw materials in the kiln requires energy up to a temperature of 1450° C and the output air waste CO2. On the other hand, the compound content of cement that can be utilized in innovation is Calcium Hydroxide (CaOH), this compound will react with pozzolan material and produces additional strength and durability of concrete, Calcium Silicate Hydrates (CSH). The objective of this research is to explore coconut fibers ash and fly ash. This material was used as cement replacement materials on cement paste. Experimental method was used in this study. SNI-03-1974-1990 is standard used to clarify the compressive strength of cement paste at the age of 7 days. The result of this study that the optimum composition of coconut fiber ash and fly ash to substitute 30% of cement with 25% and 5% for coconut fibers ash and fly ash with similar strength if to be compared normal cement paste.

  4. Digital Evaluation of Three Splinting Materials Used to Fabricate Verification Jigs for Full-Arch Implant Prostheses: A Comparative Study.

    Science.gov (United States)

    Papaspyridakos, Panos; Kim, Yong-Jeong; Finkelman, Matthew; El-Rafie, Khaled; Weber, Hans-Peter

    2017-04-01

    The primary aim of this study was to assess the accuracy of different splinting materials to make implant cast verification jigs. The secondary aim was to assess the effect of 20° implant angulation on the accuracy of casts. An edentulous mandibular arch with five internal connection tissue level implants served as control. The three implants in the anterior region were parallel to each other and the two implants in the posterior region were distally tilted 20° bilaterally. Verification jigs were fabricated with three different materials by splinting prefabricated bars to temporary abutments, resulting in three different groups (n = 15 specimens). Test casts were fabricated with low expansion type IV stone, and subsequently digitized with reference scanner. The STL files from the test casts and the control were superimposed, in order to determine the three-dimensional (3D) deviations. Group 1 (GC Pattern Resin) had a mean (SD) value of 36.59 (12.47) μm; Group 2 (Fixpeed Resin) had a mean (SD) value of 35.9 (10.13) μm; and Group 3 (Triad Gel) had a mean (SD) of 34.12 (7.10) μm. One-way ANOVA showed no statistically significant difference between groups (p = 0.790). For the comparative analysis of the effect of implant angulation, data were normally distributed for Groups 1 and 3 (GC Resin and Triad Gel), but not for group 2 (Fixpeed Resin). The difference between parallel and tilted implants was significant for all three groups: GC Resin (p = 0.024; paired t-test), Fixpeed Resin (p = 0.002; Wilcoxon signed-rank test), and Triad Gel (p = 0.002; paired t-test). There were no statistically significant differences between the 3D deviations of the test casts fabricated from verification jigs made by three materials (GC Pattern Resin, Fixpeed Resin, and Triad Gel). Parallel implants had nominally significantly less 3D deviations compared with 20° distally tilted implants, but not clinically significant. The results of the present study indicate

  5. Assessment of posterior stability in total knee replacement by stress radiographs: prospective comparison of two different types of mobile bearing implants.

    Science.gov (United States)

    Louisia, S; Siebold, R; Canty, J; Bartlett, R J

    2005-09-01

    The aim of this study was to assess the posterior stability of two different designs of total knee replacement (TKR) with deep-dished mobile bearing (MB) implants using stress X-rays. In a prospective non-randomized consecutive study, 34 patients with primary osteoarthritis of the knee underwent TKR. In group A (17 knees), they received a MB insert with a Duracon prosthesis and in group B (18 knees), a Genesis prosthesis. In all cases the posterior cruciate ligament (PCL) was resected. All patients had pre- and post-operative kneeling X-rays and were clinically evaluated with the Knee Society Score. Measurements on the radiographs were taken by tracing a line along the posterior cortex of the tibia and then measuring the perpendicular distance to a point marked at the posterior corner of Blumensaat's line. The average follow up was 10.7 months for group A and 5.4 months for group B. No statistical difference could be found in terms of clinical results and pre- and post-operative kneeling X-rays between the two groups. In each group, all knees demonstrated a significant posterior tibial translation postoperatively compare to their pre-operative status (p<0.0001). There are advantages in resecting the PCL in TKR: mobile flexion gap, correction of fixed deformity, more flexibility to adjust the joint line. The use of a deep dished polyethylene (PE) insert provides stability and use of MB insert reduces PE wear whilst retaining congruity. Two designs of deep-dished MB inserts showed significant posterior tibial translation on stress X-rays. It remains to be determined what amount of laxity is optimal for clinical function and polyethylene longevity.

  6. Breast Implants: Saline vs. Silicone

    Science.gov (United States)

    ... differ in material and consistency, however. Saline breast implants Saline implants are filled with sterile salt water. ... of any age for breast reconstruction. Silicone breast implants Silicone implants are pre-filled with silicone gel — ...

  7. Replacement of reserves zinc based on the recycling of technogenic raw materials

    Directory of Open Access Journals (Sweden)

    Olga Sergeevna Bryantseva

    2013-06-01

    Full Text Available In the article, the perspective trends of the expansion of the mineral-ore base of the Russian producers of zinc by recycling of technogenic raw materials are considered. The important role of recycling of resources for sustainable development of society and improve the environmental safety is justified. The main structural and dynamic characteristics of the use of mineral resource base for the production of zinc in Russia are considered. Raw materials opportunities and constraints for the development of zinc production are analyzed. In the paper, the structure and dynamics of the use of recycled materials by the largest producer of zinc in Russia are investigated. The methodical approach to the estimation of effectiveness of the industrial processing of technogenic metallurgical raw materials with the strategic flexibility of the implementation of projects is proposed and approved. The estimation of the effectiveness of a complex industrial processing of metallurgical zinc-containing dusts in a real production is carried out. The value of the strategic flexibility of the project of the industrial processing of the zinc-containing technogenic raw material is determined on the basis of the developed systematic approach. The value of the processes of recycling for sustainable production of zinc in Russia is revealed.

  8. Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants.

    Science.gov (United States)

    Gryshkov, Oleksandr; Klyui, Nickolai I; Temchenko, Volodymyr P; Kyselov, Vitalii S; Chatterjee, Anamika; Belyaev, Alexander E; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

    2016-11-01

    Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO2) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application.

  9. [A comparative study of mechanical properties of materials for custom-made impression trays used by implant-fixed restorations].

    Science.gov (United States)

    Gvetadze, R Sh; Abramian, S V; Rusanov, F S; Nubarian, A P; Ivanov, A A

    2012-01-01

    Materials for custom-made impression trays used for impression by implant fixed restorations were compared in the study. The analysis included such values as flexural strength and elasticity modulus, impression material adhesion strength with the use of adhesive and without it. Light-cured plastic Elite LC Tray had the best rates of bending strength and elasticity modulus and the Protakril M had the highest adhesion strength both with and without adhesive.

  10. Finite Element Analysis of the Effect of Superstructure Materials and Loading Angle on Stress Distribution around the Implant

    Directory of Open Access Journals (Sweden)

    Jafari K

    2014-12-01

    Full Text Available Statement of Problem: A general process in implant design is to determine the reason of possible problems and to find the relevant solutions. The success of the implant depends on the control technique of implant biomechanical conditions. Objectives: The goal of this study was to evaluate the influence of both abutment and framework materials on the stress of the bone around the implant by using threedimensional finite element analysis. Materials and Methods: A three-dimensional model of a patient’s premaxillary bone was fabricated using Cone Beam Computed Tomography (CBCT. Then, three types of abutment from gold, nickel-chromium and zirconia and also three types of crown frame from silver-palladium, nickel-chromium and zirconia were designed. Finally, a 178 N force at angles of zero, 30 and 45 degrees was exerted on the implant axis and the maximum stress and strain in the trabecular, cortical bones and cement was calculated. Results: With changes of the materials and mechanical properties of abutment and frame, little difference was observed in the level and distribution pattern of stress. The stress level was increased with the rise in the angle of pressure exertion. The highest stress concentration was related to the force at the angle of 45 degrees. The results of the cement analysis proved an inverse relationship between the rate of elastic modulus of the frame material and that of the maximum stress in the cement. Conclusions: The impact of the angle at which the force was applied was more significant in stress distribution than that of abutment and framework core materials.

  11. Hazardous Material / Waste Site Assessment: US 701 Bridge Replacement Project Over the Great Pee Dee River, Pee Dee River Overflow, and Lake Yauhannah Horry & Georgetown Counties, South Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This record is an unpublished report evaluating the hazardous material / waste management impacts of a future bridge replacement project on highway 701 at Yauhannah...

  12. Titanium alloys in total joint replacement--a materials science perspective.

    Science.gov (United States)

    Long, M; Rack, H J

    1998-09-01

    Increased use of titanium alloys as biomaterials is occurring due to their lower modulus, superior biocompatibility and enhanced corrosion resistance when compared to more conventional stainless steels and cobalt-based alloys. These attractive properties were a driving force for the early introduction of alpha (cpTi) and alpha + beta (Ti-6A1-4V) alloys as well as for the more recent development of new Ti-alloy compositions and orthopaedic metastable beta titanium alloys. The later possess enhanced biocompatibility, reduced elastic modulus, and superior strain-controlled and notch fatigue resistance. However, the poor shear strength and wear resistance of titanium alloys have nevertheless limited their biomedical use. Although the wear resistance of beta-Ti alloys has shown some improvement when compared to alpha + beta alloys, the ultimate utility of orthopaedic titanium alloys as wear components will require a more complete fundamental understanding of the wear mechanisms involved. This review examines current information on the physical and mechanical characteristics of titanium alloys used in artifical joint replacement prostheses, with a special focus on those issues associated with the long-term prosthetic requirements, e.g., fatigue and wear.

  13. Digital Resolution Requirements for Replacing Text-Based Material: Methods for Benchmarking Image Quality. Tutorial.

    Science.gov (United States)

    Kenney, Anne R.; Chapman, Stephen

    This tutorial provides a means to estimate resolution requirements for the use of digital imaging technology in converting text-based material. It is suggested that benchmarks for resolution can be calculated by evaluating the physical attributes of source documents and by applying Quality Index formulas that have been derived from those…

  14. Replacing noble metals with alternative materials in plasmonics and metamaterials: how good an idea?

    Science.gov (United States)

    Khurgin, Jacob B

    2017-03-28

    Noble metals that currently dominate the fields of plasmonics and metamaterials suffer from large ohmic losses. Some of the new plasmonic materials, such as doped oxides and nitrides, have smaller material loss, and using them in place of metals carries the promise of reduced-loss plasmonic and metamaterial structures, with sharper resonances and higher field concentrations. This promise is put to a rigorous analytical test in this work, which reveals that having low material loss is not sufficient to have reduced modal loss in plasmonic structures. To reduce the modal loss, it is absolutely necessary for the plasma frequency to be significantly higher than the operational frequency. Using examples of nanoparticle plasmons and gap plasmons one comes to the conclusion that, even in the mid-infrared spectrum, metals continue to hold an advantage over alternative media when it comes to propagation distances and field enhancements. Of course, the new materials still have an application niche where high absorption loss is beneficial, e.g. in medicine and thermal photovoltaics.This article is part of the themed issue 'New horizons for nanophotonics'. © 2017 The Author(s).

  15. Replacing noble metals with alternative materials in plasmonics and metamaterials: how good an idea?

    Science.gov (United States)

    Khurgin, Jacob B.

    2017-03-01

    Noble metals that currently dominate the fields of plasmonics and metamaterials suffer from large ohmic losses. Some of the new plasmonic materials, such as doped oxides and nitrides, have smaller material loss, and using them in place of metals carries the promise of reduced-loss plasmonic and metamaterial structures, with sharper resonances and higher field concentrations. This promise is put to a rigorous analytical test in this work, which reveals that having low material loss is not sufficient to have reduced modal loss in plasmonic structures. To reduce the modal loss, it is absolutely necessary for the plasma frequency to be significantly higher than the operational frequency. Using examples of nanoparticle plasmons and gap plasmons one comes to the conclusion that, even in the mid-infrared spectrum, metals continue to hold an advantage over alternative media when it comes to propagation distances and field enhancements. Of course, the new materials still have an application niche where high absorption loss is beneficial, e.g. in medicine and thermal photovoltaics. This article is part of the themed issue 'New horizons for nanophotonics'.

  16. Materials design considerations involved in the fabrication of implantable bionics by metallization of ceramic substrates.

    Science.gov (United States)

    Patel, Sunil; Guenther, Thomas; Dodds, Christopher W D; Kolke, Sergej; Privat, Karen L; Matteucci, Paul B; Suaning, Gregg J

    2013-01-01

    The Pt metallization of co-fired Al2O3/SiO2 substrates containing Pt feedthroughs was shown to be a suitable means to construct implantable bionics. The use of forge welding to join an electrode to such a metallized feedthrough was demonstrated and subsequently evaluated through the use of metallography and electron microscopy. Metallurgical phenomena involved in forge welding relevant to the fabrication of all types of biomedical implants are discussed within this paper. The affect of thermal profiles used in brazing or welding to build implantable devices from metal components is analysed and the case for considered selection of alloys in implant design is put forward.

  17. Silica/quercetin sol-gel hybrids as antioxidant dental implant materials

    Science.gov (United States)

    Catauro, Michelina; Papale, Ferdinando; Bollino, Flavia; Piccolella, Simona; Marciano, Sabina; Nocera, Paola; Pacifico, Severina

    2015-06-01

    The development of biomaterials with intrinsic antioxidant properties could represent a valuable strategy for preventing the onset of peri-implant diseases. In this context, quercetin, a naturally occurring flavonoid, has been entrapped at different weight percentages in a silica-based inorganic material by a sol-gel route. The establishment of hydrogen bond interactions between the flavonol and the solid matrix was ascertained by Fourier transform infrared spectroscopy. This technique also evidenced changes in the stretching frequencies of the quercetin dienonic moiety, suggesting that the formation of a secondary product occurs. Scanning electron microscopy was applied to detect the morphology of the synthesized materials. Their bioactivity was shown by the formation of a hydroxyapatite layer on sample surface soaked in a fluid that simulates the composition of human blood plasma. When the potential release of flavonol was determined by liquid chromatography coupled with ultraviolet and electrospray ionization tandem mass spectrometry techniques, the eluates displayed a retention time that was 0.5 min less than quercetin. Collision-activated dissociation mass spectrometry and untraviolet-visible spectroscopy were in accordance with the release of a quercetin derivative. The antiradical properties of the investigated systems were evaluated by DPPH and ABTS methods, whereas the 2,7-dichlorofluorescein diacetate assay highlighted their ability to inhibit the H2O2-induced intracellular production of reactive oxygen species in NIH-3T3 mouse fibroblast cells. Data obtained, along with data gathered from the MTT cytotoxicity test, revealed that the materials that entrapped the highest amount of quercetin showed notable antioxidant effectiveness.

  18. Ni ion release, osteoblast-material interactions, and hemocompatibility of hafnium-implanted NiTi alloy.

    Science.gov (United States)

    Zhao, Tingting; Li, Yan; Zhao, Xinqing; Chen, Hong; Zhang, Tao

    2012-04-01

    Hafnium ion implantation was applied to NiTi alloy to suppress Ni ion release and enhance osteoblast-material interactions and hemocompatibility. The auger electron spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscope results showed that a composite TiO(2)/HfO(2) nanofilm with increased surface roughness was formed on the surface of NiTi, and Ni concentration was reduced in the superficial surface layer. Potentiodynamic polarization tests displayed that 4 mA NiTi sample possessed the highest E(br) - E(corr), 470 mV higher than that of untreated NiTi, suggesting a significant improvement on pitting corrosion resistance. Inductively coupled plasma mass spectrometry tests during 60 days immersion demonstrated that Ni ion release rate was remarkably decreased, for example, a reduction of 67% in the first day. The water contact angle increased and surface energy decreased after Hf implantation. Cell culture and methyl-thiazol-tetrazolium indicated that Hf-implanted NiTi expressed enhanced osteoblasts adhesion and proliferation, especially after 7 days culture. Hf implantation decreased fibrinogen adsorption, but had almost no effect on albumin adsorption. Platelets adhesion and activation were suppressed significantly (97% for 4 mA NiTi) and hemolysis rate was decreased by at least 57% after Hf implantation. Modified surface composition and morphology and decreased surface energy should be responsible for the improvement of cytocompatibility and hemocompatibility. Copyright © 2011 Wiley Periodicals, Inc.

  19. Thin hydroxyapatite surface layers on titanium produced by ion implantation

    CERN Document Server

    Baumann, H; Bilger, G; Jones, D; Symietz, I

    2002-01-01

    In medicine metallic implants are widely used as hip replacement protheses or artificial teeth. The biocompatibility is in all cases the most important requirement. Hydroxyapatite (HAp) is frequently used as coating on metallic implants because of its high acceptance by the human body. In this paper a process is described by which a HAp surface layer is produced by ion implantation with a continuous transition to the bulk material. Calcium and phosphorus ions are successively implanted into titanium under different vacuum conditions by backfilling oxygen into the implantation chamber. Afterwards the implanted samples are thermally treated. The elemental composition inside the implanted region was determined by nuclear analysis methods as (alpha,alpha) backscattering and the resonant nuclear reaction sup 1 H( sup 1 sup 5 N,alpha gamma) sup 1 sup 2 C. The results of X-ray photoelectron spectroscopy indicate the formation of HAp. In addition a first biocompatibility test was performed to compare the growing of m...

  20. In vitro cytotoxicity and surface topography evaluation of additive manufacturing titanium implant materials.

    Science.gov (United States)

    Tuomi, Jukka T; Björkstrand, Roy V; Pernu, Mikael L; Salmi, Mika V J; Huotilainen, Eero I; Wolff, Jan E H; Vallittu, Pekka K; Mäkitie, Antti A

    2017-03-01

    Custom-designed patient-specific implants and reconstruction plates are to date commonly manufactured using two different additive manufacturing (AM) technologies: direct metal laser sintering (DMLS) and electron beam melting (EBM). The purpose of this investigation was to characterize the surface structure and to assess the cytotoxicity of titanium alloys processed using DMLS and EBM technologies as the existing information on these issues is scarce. "Processed" and "polished" DMLS and EBM disks were assessed. Microscopic examination revealed titanium alloy particles and surface flaws on the processed materials. These surface flaws were subsequently removed by polishing. Surface roughness of EBM processed titanium was higher than that of DMLS processed. The cytotoxicity results of the DMLS and EBM discs were compared with a "gold standard" commercially available titanium mandible reconstruction plate. The mean cell viability for all discs was 82.6% (range, 77.4 to 89.7) and 83.3% for the control reconstruction plate. The DMLS and EBM manufactured titanium plates were non-cytotoxic both in "processed" and in "polished" forms.

  1. Titanium-35niobium alloy as a potential material for biomedical implants: In vitro study.

    Science.gov (United States)

    de Andrade, Dennia Perez; de Vasconcellos, Luana Marotta Reis; Carvalho, Isabel Chaves Silva; Forte, Lilibeth Ferraz de Brito Penna; de Souza Santos, Evelyn Luzia; Prado, Renata Falchete do; Santos, Dalcy Roberto Dos; Cairo, Carlos Alberto Alves; Carvalho, Yasmin Rodarte

    2015-11-01

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium-niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti-35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti-35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti-35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti-35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Enhancing the antibacterial performance of orthopaedic implant materials by fibre laser surface engineering

    DEFF Research Database (Denmark)

    Chan, Chi-Wai; Carson, Louise; Smith, Graham C.

    2017-01-01

    Implant failure caused by bacterial infection is extremely difficult to treat and usually requires the removal of the infected components. Despite the severe consequence of bacterial infection, research into bacterial infection of orthopaedic implants is still at an early stage compared to the ef......Implant failure caused by bacterial infection is extremely difficult to treat and usually requires the removal of the infected components. Despite the severe consequence of bacterial infection, research into bacterial infection of orthopaedic implants is still at an early stage compared...... for the first time. Laser surface treatment was performed by a continuous wave (CW) fibre laser with a near-infrared wavelength of 1064 nm in a nitrogen-containing environment. Staphylococcus aureus, commonly implicated in infection associated with orthopaedic implants, was used to investigate the antibacterial...

  3. Fracture Strength of Three-Unit Implant Supported Fixed Partial Dentures with Excessive Crown Height Fabricated from Different Materials

    Directory of Open Access Journals (Sweden)

    Vahideh Nazari

    2017-01-01

    Full Text Available Objectives: Fracture strength is an important factor influencing the clinical long-term success of implant-supported prostheses especially in high stress situations like excessive crown height space (CHS. The purpose of this study was to compare the fracture strength of implant-supported fixed partial dentures (FPDs with excessive crown height, fabricated from three different materials.Materials and Methods: Two implants with corresponding abutments were mounted in a metal model that simulated mandibular second premolar and second molar. Thirty 3-unit frameworks with supportive anatomical design were fabricated using zirconia, nickel-chromium alloy (Ni-Cr, and polyetheretherketone (PEEK (n=10. After veneering, the CHS was equal to 15mm. Then; samples were axially loaded on the center of pontics until fracture in a universal testing machine at a crosshead speed of 0.5 mm/minute. The failure load data were analyzed by one-way ANOVA and Games-Howell tests at significance level of 0.05.Results: The mean failure loads for zirconia, Ni-Cr and PEEK restorations were 2086±362N, 5591±1200N and 1430±262N, respectively. There were significant differences in the mean failure loads of the three groups (P<0.001. The fracture modes in zirconia, metal ceramic and PEEK restorations were cohesive, mixed and adhesive type, respectively.Conclusions: According to the findings of this study, all implant supported three-unit FPDs fabricated of zirconia, metal ceramic and PEEK materials are capable to withstand bite force (even para-functions in the molar region with excessive CHS.Keywords: Dental Implants; Polyetheretherketone; Zirconium oxide; Dental Restoration Failure; Dental Porcelain

  4. Material reenactment: The missing and replaced paintings of Malevich’s 1929 retrospective

    Directory of Open Access Journals (Sweden)

    Marie Gasper-Hulvat

    2016-12-01

    Full Text Available In 1927, Russian avant-garde artist Kazimir Malevich was recalled by Soviet authorities from Berlin, where he had received critical acclaim during a journey abroad. He returned to Moscow, leaving behind in Germany the paintings with which he had travelled. It was a cache that represented his entire painterly career. In 1929, Malevich found himself granted a retrospective exhibition at the foremost museum of Russian art in the Soviet capital, the Tretiakov Gallery. With the bulk of the material evidence of his career now missing, the artist responded by producing forty new canvases. In this article, I propose that Malevich’s exhibition of 1929 represented an attempt to materially reenact his own career, producing a counterfeit simulation of what might have happened. Furthermore, I explain how an exhibition of his work held in 2000 signifi cantly altered the scholarly discussion of the works displayed in 1929. Nel 1927, le autorità sovietiche richiamarono l’artista dell’avanguardia russa Kazimir Malevich da Berlino, dove si era recato per un viaggio all’estero e dove aveva ricevuto un’accoglienza critica. Malevich tornò a Mosca lasciando in Germania le opere con le quali aveva viaggiato, una serie che documentava interamente la sua carriera pittorica. Nella capitale sovietica gli fu dedicata, due anni dopo, una mostra retrospettiva, ospitata dal principale museo di arte russa di Mosca, la Galleria Tretiakov. Sebbene buona parte delle prove materiali del suo lavoro fosse andata perduta, l’artista rispose producendo quaranta nuove tele. Scopo di questo articolo è dimostrare come la mostra del 1929 costituisca un tentativo, da parte di Malevich, di ricostruire la sua carriera per produrre una simulazione di quello che avrebbe potuto essere. Inoltre si documenta come una mostra dedicata nel 2000 all’artista ha contribuito all’analisi critica della esposizione del 1929.

  5. USE OF PLASTIC MATERIAL AND TRIPLE SCAN IN THE PREPARATION OF SURGICAL GUIDES FOR THE DENTAL IMPLANT TREATMENT-CASE REPORT

    OpenAIRE

    Rosen Borisov

    2016-01-01

    The use of surgical guides in implant treatment increases the accuracy of the dental implant positioning compared with manual methods. Regardless of how they are made, deviations of implants from their intended position are established in all kinds of surgical guides. This article considers the use of plastic material and new scanning technique for the production of CAD/CAM surgical guides that aim to overcome the deficiencies of the currently applied technologies in the production of surgica...

  6. Analysis in vitro of the cytotoxicity of potential implant materials. I: Zirconia-titania sintered ceramics.

    Science.gov (United States)

    Marchi, Juliana; Ussui, Valter; Delfino, Carina S; Bressiani, Ana H A; Marques, Márcia M

    2010-08-01

    Zirconia (ZrO2) is a bioinert, strong, and tough ceramic, while titania (TiO2) is bioactive but has poor mechanical properties. It is expected that ZrO2-TiO2 mixed ceramics incorporate the individual properties of both ceramics, so that this material would exhibit better biological properties. Thus, the objective of this study was to compare the biocompatibility properties of ZrO2-TiO2 mixed ceramics. Sintered ceramics pellets, obtained from powders of TiO2, ZrO2, and three different ZrO2-TiO2 mixed oxides were used. Roughnesses, X-ray diffraction, microstructure through SEM, hardness, and DRIFT characterizations were performed. For biocompatibility analysis cultured FMM1 fibroblasts were plated on the top of disks and counted in SEM micrographs 1 and 2 days later. Data were compared by ANOVA complemented by Tukey's test. All samples presented high densities and similar microstructure. The H2O content in the mixed ceramics was more evident than in pure ceramics. The number of fibroblasts attached to the disks increased significantly independently of the experimental group. The cell growth on the top of the ZrO2-TiO2 samples was similar and significantly higher than those of TiO2 and ZrO2 samples. Our in vitro experiments showed that the ZrO2-TiO2 sintered ceramics are biocompatible allowing faster cell growth than pure oxides ceramics. The improvement of hardness is proportional to the ZrO2 content. Thus, the ZrO2-TiO2 sintered ceramics could be considered as potential implant material.

  7. The use of a masticatory robot to analyze the shock absorption capacity of different restorative materials for implant prosthesis

    Directory of Open Access Journals (Sweden)

    M. Menini

    2011-01-01

    Full Text Available The aim of the present research was to measure in vitro the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto the dental implant. A masticatory robot that is able to reproduce the mandibular movements and the forces exerted during mastication was used. The forces transmitted to the simulated periimplant bone during the robot mastication were analysis of variance (ANOVA was used. The zirconia and the ceramic crowns transmitted significantly greater forces (p-value < 0.0001 than the other crowns tested. Dental materials with lower elastic modulus were better able to ansorb shock from acclusal forces than more rigid materials.

  8. Current concepts of regenerative biomaterials in implant dentistry

    Directory of Open Access Journals (Sweden)

    Annapurna Ahuja

    2015-01-01

    Full Text Available The primary objective of any implant system is to achieve firm fixation to the bone and this could be influenced by biomechanical as well as biomaterial selection. An array of materials is used in the replacement of missing teeth through implantation. The appropriate selection of biomaterials directly influences the clinical success and longevity of implants. Thus the clinician needs to have adequate knowledge of the various biomaterials and their properties for their judicious selection and application in his/her clinical practice. The recent materials such as bioceramics and composite biomaterials that are under consideration and investigation have a promising future. For optimal performance, implant biomaterials should have suitable mechanical strength, biocompatibility, and structural biostability in the physiological environment. This article reviews the various implant biomaterials and their ease of use in implant dentistry.

  9. RESULTS OF THE FOSFOMYCIN APPLICATION FOR THE IMPREGNATION OF BONE REPLACEMENT MATERIALS IN THE TREATMENT OF CHRONIC OSTEOMYELITIS

    Directory of Open Access Journals (Sweden)

    V. A. Konev

    2016-01-01

    rapid elimination of the bacteria. Reaction of the adjacent tissue to the implanted material and results of X-ray imaging in both groups did not differ significantly. Long duration of the broad-spectrum antimicrobial activity of the bone cement with fosfomycin with the comparable perifocal reaction in vivo necessitates further study of the use of this antibiotic in bioresorbable materials for the treatment of osteomyelitis in clinical practice.

  10. Two different techniques of manufacturing TMJ replacements - A technical report.

    Science.gov (United States)

    Kozakiewicz, Marcin; Wach, Tomasz; Szymor, Piotr; Zieliński, Rafał

    2017-09-01

    Presently, during the surgical treatment of the patients in maxillofacial surgery, one can use various medical implants. Moreover custom made implants are being used. Replacements may be fitted to the structure and shape of the human skull owing to CAD/CAM (custom aided design/manufacture) called customized implants. This study was aimed to report for the first time clinical material from which custom implants, using two different techniques, were manufactured to reconstruct the temporomandibular joint (TMJ). In this study, eleven patients with an average age of 54 years were included. All of the patients underwent TMJ reconstruction using direct metal laser sintering (DMLS) or computer numerical control milling (CNC) techniques for implant manufacture. Four of the eleven patients had a malignancy diagnosis, and seven had a benign diagnosis. Patients complained of hypomobility of the TMJ, facial asymmetry, pain and swelling of the preauricular region. Treatment included 7 CNC milled implants and 4 implants in DMLS. More metallic implant parts with a rough surface were associated with the DMLS technique. Post operational, uneventful healing was observed in all clinical cases during an average of 26.8 months of follow-up. Three months post-operation, facial nerve palsy, swallowing disturbances and pain were not observed. Infections, allergic reactions to materials and re-ankylosis were also not observed. Replacements received correct forms and functions owing to the CAM techniques. Post-operational maximal interincisal opening improved (p < 0.01) and was not significantly related to preoperational opening, age, sex, diagnosis or adjuvant radiotherapy. Considering both methods, the feature that differentiates the manufacture technique is the more subtractive surface finishing required for the DMLS implant than the CNC implant. Both techniques resulted the same clinical outcomes and can be used successfully in patients with neoplastic lesions and other TMJ disorders

  11. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten

    2013-01-01

    OBJECTIVES: The purpose of this clinical study was to describe outcome variables of all-ceramic and metal-ceramic implant-supported, single-tooth restorations. MATERIALS AND METHODS: A total of 59 patients (mean age: 27.9 years) with tooth agenesis and treated with 98 implant-supported single...

  12. Implante de tubo valvulado bioprótese "stentless" em posição aórtica: estudo experimental em ovinos A juvenile sheep model for the stentless bioprostheses implanted as aortic root replacements

    Directory of Open Access Journals (Sweden)

    Paulo César SANTOS

    2002-03-01

    Full Text Available INTRODUÇÃO: O tratamento das lesões valvares representa um grande desafio dentro da cirurgia cardiovascular, pois, até os dias atuais, não temos um substituto ideal para as valvas do coração. As próteses atualmente disponíveis apresentam vantagens e desvantagens; as mecânicas exigem anticoagulação definitiva e as biológicas apresentam baixa durabilidade. Para se chegar a um substituto ideal, são necessárias várias fases, desde a escolha e o preparo do material até o implante em animal de grande porte. Esta última é muito importante, pois a escolha do animal deve ser criteriosa. Ovinos juvenís são animais dóceis de fácil manipulação e suas características anatômicas e biológicas se assemelham muito ao que ocorre com o ser humano e as próteses "stentless" são substitutos mais próximos dos homoenxertos. MATERIAL E MÉTODO: Foram operados 30 ovinos juvenís com idade variando de 4,4 a 6,3 meses, peso de 25 a 37 kg, sendo 28 machos. Todos os animais foram submetidos a circulação extracorpórea para implante de bioprótese "stentless" montada em tubo de aorta porcina, com reimplante de artérias coronárias. A operação foi realizada com hipotermia moderada e cardioplegia gelada. O período de seguimento foi de 30 dias e, ao final, realizado ecocardiograma. RESULTADOS: Houve 8 (26,6% óbitos no intra-operatório e 6 (27,7% óbitos no seguimento. O tempo médio de CEC foi de 98 min. Foi realizado ecocardiograma em 16 animais e em nenhum caso foram vistos sinais de endocardite ou outras alterações; a fração média de ejeção foi de 74%. CONCLUSÃO: Este modelo experimental utilizando ovinos para o estudo de biopróteses "stentless" em posição aórtica mostrou-se bem reprodutível e a performance do enxerto bastante factível de ser avaliada, pois ovinos são animais dóceis e de fácil manipulação no seguimento tardio.INTRODUCTION: Often, studies on aortic prosthetic valves analyze their performance not at the

  13. Dental materials and their performance for the management of screw access channels in implant-supported restorations.

    Science.gov (United States)

    Raab, Philipp; Alamanos, Christos; Hahnel, Sebastian; Papavasileiou, Dimitrios; Behr, Michael; Rosentritt, Martin

    2017-03-31

    Unsuccessfully sealed screw access channels of prosthetic implant abutments may lead to malodor or peri-implant diseases in gingival tissues adjacent to implant-supported restorations. Therefore, 72 sets of screw channel analogs with six different materials incorporated (Polytetrafluoroethylene (PTFE), wax, gutta-percha, cavit, endofrost-pellets and cotton pellets) were exposed (2.5 h, 37°C) to Streptococcus mutans, oralis and Candida albicans suspensions. Bacterial adherence was quantified by using the fluorescence dye, Alamar Blue/resazurin, and an automated multifunctional reader. For quantification of fungal adherence the ATP-based bioluminescence approach was used. High relative fluorescence and luminescence intensities (>10,000), indicating high adhesion of streptococci and fungi were found for cotton and endofrost-pellets and low intensities (wax, gutta-percha, cavit and PTFE. The quantity of bacterial and fungal adhesion differed significantly between the assessed various sealing materials. In conclusion and within the limitations of this study, wax, gutta-percha, cavit and PTFE should be preferred as sealing materials.

  14. Implants for surgery -- Metallic materials -- Part 3: Wrought titanium 6-aluminium 4-vanadium alloy

    CERN Document Server

    International Organization for Standardization. Geneva

    1996-01-01

    Specifies the characteristics of, and corresponding test methods for, the wrought titanium alloy known as titanium 6-aluminium 4-vanadium alloy (Ti 6-Al 4-V alloy) for use in the manufacture of surgical implants.

  15. Matrix Vesicle Enzyme Activity and Phospholipid Content in Endosteal Bone Following Implantation of Osseointegrating and Non-Osseointegrating Implant Materials.

    Science.gov (United States)

    1991-11-01

    matrix vesicles (Schwartz et al., 1990a; Boyan et al., 1988; Peress et al., 1974) and is intimately associated with mineral formation as the principle...directly related to the process of primary mineral formation in tissues adjacent to osseointegrating and non- integrating materials. Of particular...Evans, L. 1981. Mechanisms of mineral formation by matrix vesicles. In: Matrix Vesicles, Proc. 3rd Int. Conf. Matrix Vesicles. Ascenci, A., Bonucci, D

  16. Method of ions acceleration for laser-induced implantation of semiconductor materials

    Science.gov (United States)

    Czarnecka, A.; Badziak, J.; Parys, P.; Rosinski, M.; Wołowski, J.

    The application of electrostatic fields for the formation of laser-generated ions makes it possible to control the ion stream parameters in broad energy and current density ranges. It also permits to remove the useless ions from the ion stream designed for laser-induced implantation and deposition of layers of semiconductor materials. For acceleration of ions a special electrostatic system has been completed and tested at the Institute of Plasma Physics and Laser Microfusion (IPPLM). A repetitive Nd: glass laser with energy of ˜0.5 J in a 3.5 ns pulse, wavelength of 1.06 μm, repetition rate of up to 10 Hz and intensity on the target of up to 1011 W cm-2, has been recently employed to produce ions emitted from irradiated solid targets. The movable target holder was located inside the cylindrical box connected with a high-voltage source (up to 50 kV). The ions passing through the diaphragm in this box were accelerated in the system of electrodes in the electrostatic field formed in the gap between the box and a grid mounted at the end of the grounded cylindrical electrode. The parameters of the ion streams were measured with the use of several ion collectors and an electrostatic ion energy analyzer (IEA). The Ge ion stream attained energy of up to 30 keV and ion fluency 1011 ions/cm2 for one laser shot. The maximum ion charge state measured with the use of IEA was 3+.

  17. Titanium–35niobium alloy as a potential material for biomedical implants: In vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Perez de Andrade, Dennia; Marotta Reis de Vasconcellos, Luana; Chaves Silva Carvalho, Isabel; Ferraz de Brito Penna Forte, Lilibeth; Souza Santos, Evelyn Luzia de [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, UNESP — Univ Estadual Paulista, State University of São Paulo (UNESP), Av. Engenheiro Francisco José Longo, 777, São José dos Campos 12245-000, SP (Brazil); Falchete do Prado, Renata, E-mail: renatafalchete@hotmail.com [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, UNESP — Univ Estadual Paulista, State University of São Paulo (UNESP), Av. Engenheiro Francisco José Longo, 777, São José dos Campos 12245-000, SP (Brazil); Santos, Dalcy Roberto dos; Alves Cairo, Carlos Alberto [Division of Materials, Air and Space Institute, CTA, Praça Mal. do Ar Eduardo Gomes, 14, São José dos Campos 12904-000, SP (Brazil); Rodarte Carvalho, Yasmin [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, UNESP — Univ Estadual Paulista, State University of São Paulo (UNESP), Av. Engenheiro Francisco José Longo, 777, São José dos Campos 12245-000, SP (Brazil)

    2015-11-01

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium–niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti–35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150 μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti–35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti–35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti–35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants. - Highlights: • Powder metallurgy is effective in producing porous biomaterials. • Ti–35Nb alloy improved mineralized matrix formation. • Porous surface favored a multidirectional pattern of cell spreading. • Porous surface Ti–35Nb alloy appears to be more favorable to bone formation than existing alloys.

  18. Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

    OpenAIRE

    Zhang, Bill G. X.; Myers, Damian E.; Gordon G. Wallace; Milan Brandt; Choong, Peter F. M.

    2014-01-01

    Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracell...

  19. Dental implant survival rate in well-controlled diabetic patients. A systematic review.

    OpenAIRE

    Heber Arbildo; César Lamas; Dora Camara; Hernán Vásquez

    2015-01-01

    Background: Dental implants have now become one of the most popular options for replacing a missing tooth. On the other hand, diabetes mellitus is a systemic disease that affects a large part of the population and is generally considered an absolute or relative contraindication to implant therapy. Aim: To determine the survival rate of dental implants in controlled diabetic patients through a systematic review. Material and methods: A systematic search in Pubmed, SciELO and RedALyC databases...

  20. Titanium coated with functionalized carbon nanotubes — A promising novel material for biomedical application as an implantable orthopaedic electronic device

    Energy Technology Data Exchange (ETDEWEB)

    Przekora, Agata, E-mail: agata.przekora@umlub.pl [Department of Biochemistry and Biotechnology, Medical University of Lublin, Faculty of Pharmacy with Medical Analytics Division, Chodzki 1, 20-093 Lublin (Poland); Benko, Aleksandra; Nocun, Marek; Wyrwa, Jan; Blazewicz, Marta [Faculty of Materials Science and Ceramics, AGH-Univ. of Science and Technology, A. Mickiewicz 30 Ave., 30-059 Cracow (Poland); Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Faculty of Pharmacy with Medical Analytics Division, Chodzki 1, 20-093 Lublin (Poland)

    2014-12-01

    The aim of the study was to fabricate titanium (Ti) material coated with functionalized carbon nanotubes (f-CNTs) that would have potential medical application in orthopaedics as an implantable electronic device. The novel biomedical material (Ti-CNTs-H{sub 2}O) would possess specific set of properties, such as: electrical conductivity, non-toxicity, and ability to inhibit connective tissue cell growth and proliferation protecting the Ti-CNTs-H{sub 2}O surface against covering by cells. The novel material was obtained via an electrophoretic deposition of CNTs-H{sub 2}O on the Ti surface. Then, physicochemical, electrical, and biological properties were evaluated. Electrical property evaluation revealed that a Ti-CNTs-H{sub 2}O material is highly conductive and X-ray photoelectron spectroscopy analysis demonstrated that there are mainly COOH groups on the Ti-CNTs-H{sub 2}O surface that are found to inhibit cell growth. Biological properties were assessed using normal human foetal osteoblast cell line (hFOB 1.19). Conducted cytotoxicity tests and live/dead fluorescent staining demonstrated that Ti-CNTs-H{sub 2}O does not exert toxic effect on hFOB cells. Moreover, fluorescence laser scanning microscope observation demonstrated that Ti-CNTs-H{sub 2}O surface retards to a great extent cell proliferation. The study resulted in successful fabrication of highly conductive, non-toxic Ti-CNTs-H{sub 2}O material that possesses ability to inhibit osteoblast proliferation and thus has a great potential as an orthopaedic implantable electronic device. - Highlights: • Functionalized carbon nanotubes were electrophoretically deposited on Ti surface. • Physicochemical, electrical, and biological properties were evaluated. • Ti-CNTs-H{sub 2}O is highly conductive and there are mainly COOH groups on its surface. • Novel material is non-toxic and retards to a great extent osteoblast proliferation. • Ti-CNTs-H{sub 2}O has a promising potential as implantable orthopaedic

  1. Characterising structural, mechanical and cytotoxic properties of coral-based composite material intended for bone implant applications

    Directory of Open Access Journals (Sweden)

    Angela Samper Gaitán

    2011-08-01

    Full Text Available Studies concerning the application of Porites asteroides coral for bone implant purposes have demonstrated the biological viability of its use. As a complement to previous research regarding the development of bone-powder based composite materials which are useful for such applications, this study was aimed at developing a coral powder-based composite material which would be able to satisfy the appropriate structural, mechanical and cytotoxic properties required for its use. A composite material made of coral powder, calcium sulphate powder and water was therefore developed, and its properties were tested in different compositions. The results showed how the resulting composite material had properties which were comparable to those of human cortical bone (from both a structural and mechanical point of view, as well as being non-toxic below a 0.35 mg/ml critical composite material concentration.

  2. Fracture Strength of Three-Unit Implant Supported Fixed Partial Dentures with Excessive Crown Height Fabricated from Different Materials

    Science.gov (United States)

    Nazari, Vahideh; Ghodsi, Safoura; Alikhasi, Marzieh; Shamshiri, Ahmad Reza

    2016-01-01

    Objectives: Fracture strength is an important factor influencing the clinical long-term success of implant-supported prostheses especially in high stress situations like excessive crown height space (CHS). The purpose of this study was to compare the fracture strength of implant-supported fixed partial dentures (FPDs) with excessive crown height, fabricated from three different materials. Materials and Methods: Two implants with corresponding abutments were mounted in a metal model that simulated mandibular second premolar and second molar. Thirty 3-unit frameworks with supportive anatomical design were fabricated using zirconia, nickel-chromium alloy (Ni-Cr), and polyetheretherketone (PEEK) (n=10). After veneering, the CHS was equal to 15mm. Then; samples were axially loaded on the center of pontics until fracture in a universal testing machine at a crosshead speed of 0.5 mm/minute. The failure load data were analyzed by one-way ANOVA and Games-Howell tests at significance level of 0.05. Results: The mean failure loads for zirconia, Ni-Cr and PEEK restorations were 2086±362N, 5591±1200N and 1430±262N, respectively. There were significant differences in the mean failure loads of the three groups (Pzirconia, metal ceramic and PEEK restorations were cohesive, mixed and adhesive type, respectively. Conclusions: According to the findings of this study, all implant supported three-unit FPDs fabricated of zirconia, metal ceramic and PEEK materials are capable to withstand bite force (even para-functions) in the molar region with excessive CHS. PMID:28243301

  3. Evaluation of accuracy of casts of multiple internal connection implant prosthesis obtained from different impression materials and techniques: an in vitro study.

    Science.gov (United States)

    Pujari, Malesh; Garg, Pooja; Prithviraj, D R

    2014-04-01

    Movement of impression copings inside the impression material using a direct (open tray) impression technique during clinical and laboratory phases may cause inaccuracy in transferring the 3-dimensional spatial orientation of implants intraorally to the cast. Consequently, the prosthesis may require corrective procedures. This in vitro study evaluated the accuracy of 3 different impression techniques using polyether and vinyl polysiloxane (VPS) impression material to obtain a precise cast for multiple internal connection implants. A reference acrylic resin model with 4 internal connection implants was fabricated. Impressions of the reference model were made using 3 different techniques and 2 different impression materials. The study consisted of 24 specimens divided into 6 groups of 4 each. Impressions were poured with ADA type IV stone (Kalrock, Kalabhai Karson Pvt Ltd, Mumbai, India). All casts were evaluated for the positional accuracy (mm) of the implant replica heads using a profile projector. These measurements were compared to the measurements calculated on the reference resin model, which served as a control. Data were analyzed with 2-way analysis of variance (ANOVA) followed by Bonferroni multiple comparison procedures to evaluate group means. The results revealed significant difference for anterior implant distance between the 2 impression materials (P techniques (P technique. For posterior implants, the results suggested no significant difference between the 2 impression materials (P ≥ .05). Although results were not statistically significant, the polyether impression material showed the lowest mean variation as compared to the VPS impression material. However, there was a significant difference among the 3 different techniques (P techniques, the lowest mean variation between 2 posterior implants was found in the splinted technique. Casts obtained from impression techniques using square impression copings splinted together with autopolymerizing acrylic

  4. Effect of a boron implantation on the electrical properties of epitaxial HgCdTe with different material composition

    Science.gov (United States)

    Lyapunov, D. V.; Pishchagin, A. A.; Grigoryev, D. V.; Korotaev, A. G.; Voitsekhovskii, A. V.; Kokhanenko, A. P.; Iznin, I. I.; Savytskyy, H. V.; Bonchik, A. U.; Dvoretskii, S. A.; Mikhailov, N. N.

    2016-08-01

    In this work the experimental results of investigations of the dynamics of accumulation and spatial distribution of electrically active radiation defects when irradiating epitaxial films of Hg1-xCdxTe (MCT) with different material composition (x). The films, grown by molecular beam epitaxy (MBE) were irradiated by B ions at room temperature in the radiation dose range 1012 -1015 ions/cm2 and with ion energy 100 keV. The results give the differences in implantation profiles, damage accumulation and electrical properties as a function of the material composition of the films.

  5. Materials processing towards development of rapid prototyping technology for manufacturing biomedical implants

    Science.gov (United States)

    Pekin, Senol

    2000-10-01

    Materials processing towards development of fused deposition of materials (FDM) method for manufacturing biomedical implants has been studied experimentally. Main processing steps consisted of thermoplastic binder development in the ethylene vinyl acetate (EVA)-microcrystalline wax system, feedstock extrusion, characterization and optimization of binder degradation, and sintering of calcium deficient hydroxyapatite. Differential scanning calorimetry (DSC) revealed that the melting index (MI) of the copolymer affects the temperature location of the solidification exotherm, whereas the effect on the temperature location of the melting endotherm was negligible. Nonisothermal measurement of viscosity of different blends as a function of VA content of the EVA component revealed that the microcrystalline wax is compatible with 25--14% VA-containing EVA grades. Further DSC analysis revealed that co-crystallization leads to compatible EVA-microcrystalline wax blends. A typical binder formulation that was developed in the present work has a viscosity of about 700 cP at 140°C, a compressive yield strength of 6 MPa and an elastic modulus of about 600 MPa, and contained 15--20% EVA and 80--85% microcrystalline wax. Various filaments with a nominal diameter of 1.8 mm were extruded by using such a binder, and calcium pyro-phosphate powder that had a distribution modulus of about 0.37. Measurement of physical dimensions of the filament revealed that fluid state can be achieved in the filaments. Simultaneous thermal analysis of degradation characteristics of the typical binder formulations revealed that degradation sequence is oxidation of the hydrocarbons, evaporation of the hydrocarbons, degradation of the vinyl acetate, and degradation of the ethylene chain. A rate controlled binder removal system was developed and used in order to optimize the binder removal schedule. Sintering of gel-cast calcium hydroxyapatite was studied by means of thermal analysis, XRD, mechanical

  6. Evaluation of the inflammatory potential of implant materials in a mouse model by bioluminescent imaging of intravenously injected bone marrow cells.

    Science.gov (United States)

    Rais, Bushra; Köster, Mario; Rahim, Muhammad Imran; Pils, Marina; Seitz, Jan-Marten; Hauser, Hansjörg; Wirth, Dagmar; Mueller, Peter P

    2016-09-01

    To evaluate the inflammatory potential of implants a bioluminescent imaging assay was developed using luciferase-expressing bone marrow cells that were injected into the blood circulation of wild-type mice. After subcutaneous implantation of titanium discs as an example for a clinically established biocompatible material, the luminosity was modest. Similarly, low luminosity signals were generated by pure magnesium implants that were used to represent metallic alloys that are presently under investigation as novel degradable implant materials. Increased luminosity was observed in response to degradable polymeric PLGA implants. Surgical wounds induced a basic luminescent response even in the absence of an implant. However, the material-independent response to injury could be minimized using injectable microparticle suspensions. In parallel with the resorption of biodegradable microparticles, the signal induced by PLGA declined faster when compared to non-degradable polystyrene suspensions. By using an interferon type I inducible Mx2 promoter construct to drive luciferase gene expression, the highest luminosity was observed in response to bacteria, indicating that the system could also be employed to monitor implant infections. Overall, labeled bone marrow cells yielded specific, well-defined localized signals that correlated with the inflammatory responses to implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2149-2158, 2016.

  7. Wear of cross-linked polyethylene against itself: a material suitable for surface replacement of the finger joint.

    Science.gov (United States)

    Sibly, T F; Unsworth, A

    1991-05-01

    Cross-linking of polyethylene (XLPE) has dramatically improved its properties in industrial applications, and it may also have some application in the field of human joint replacement. Additionally it has the advantage of permitting a lower molecular weight base material to be used, so that components may be injection moulded rather than machined. This study therefore investigates the wear resistance of medical grade cross-linked polyethylene (XLPE), cross-linked by a silane-grafting process, with a molecular weight between cross links of 5430 g mol(-1). This first report investigates the wear resistance of XLPE against itself, because for certain joints, such as the metacarpo-phalangeal joint, the material may have a high enough wear resistance to allow both bearing surfaces to be made from it. Tests were carried out both on a reciprocating pin and plate machine with pins loaded at 10 and 40 N and also on a new finger joint simulator, which simulates the loads applied to and the movements of, the metacarpo-phalangeal joint. An average wear rate of 1.8 x 10(-6) mm3 N-1 m-1 was found (range 0.9-2.75 x 10(-6) mm3 N-1 m-1). This is about six times greater than the wear rate of non-cross-linked ultra high molecular weight polyethylene (UHMWPE) against stainless steel, but for applications with low loading, such as the metacarpo-phalangeal joint, this material is shown to have adequate wear resistance. The coefficient of friction was 0.1, which is similar to that of UHMWPE on stainless steel.

  8. Surface characterization of titanium based dental implants; Caracterizacao de implantes odontologicos a base de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Castilho, Guilherme Augusto Alcaraz

    2006-07-01

    Dental implantology uses metallic devices made of commercially pure titanium in order to replace lost teeth. Titanium presents favorable characteristics as bio material and modern implants are capable of integrate, witch is the union between bone and implant without fibrous tissue development. Three of the major Brazilian implant manufacturers were chosen to join the study. A foreign manufacturer participated as standard. The manufacturers had three specimens of each implant with two different surface finishing, as machined and porous, submitted to analysis. Surface chemical composition and implant morphology were analyzed by X-ray photoelectron spectroscopy (XP S), scanning electron microscopy (SEM) and microprobe. Implant surface is mainly composed of titanium, oxygen and carbon. Few contaminants commonly present on implant surface were found on samples. Superficial oxide layer is basically composed of titanium dioxide (TiO{sub 2}), another oxides as Ti O and Ti{sub 2}O{sub 3} were also found in small amount. Carbon on implant surface was attributed to manufacturing process. Nitrogen, Phosphorous and Silicon appeared in smaller concentration on surface. There was no surface discrepancy among foreign and Brazilian made implants. SEM images were made on different magnification, 35 X to 3500 X, and showed similarity among as machined implants. Porous surface finishing implants presented distinct morphology. This result was attributed to differences on manufacturing process. Implant bioactivity was accessed through immersion on simulated body solution (SBF) in order to verify formation of an hydroxyapatite (HA) layer on surface. Samples were divided on three groups according to immersion time: G1 (7 days), G2 (14 days), G3 (21 days), and deep in SBF solution at 37 deg C. After being removed from solution, XPS analyses were made and then implants have been submitted to microprobe analysis. XPS showed some components of SBF solution on sample surface but microprobe

  9. Polymeric implant materials for the reconstruction of tracheal and pharyngeal mucosal defects in head and neck surgery

    Directory of Open Access Journals (Sweden)

    Rickert, Dorothee

    2009-01-01

    Full Text Available The existing therapeutical options for the tracheal and pharyngeal reconstruction by use of implant materials are described. Inspite of a multitude of options and the availability of very different materials none of these methods applied for tracheal reconstruction were successfully introduced into the clinical routine. Essential problems are insufficiencies of anastomoses, stenoses, lack of mucociliary clearance and vascularisation. The advances in Tissue Engineering (TE offer new therapeutical options also in the field of the reconstructive surgery of the trachea. In pharyngeal reconstruction far reaching developments cannot be recognized at the moment which would allow to give a prognosis of their success in clinical application. A new polymeric implant material consisting of multiblock copolymers was applied in our own work which was regarded as a promising material for the reconstruction of the upper aerodigestive tract (ADT due to its physicochemical characteristics. In order to test this material for applications in the ADT under extreme chemical, enzymatical, bacterial and mechanical conditions we applied it for the reconstruction of a complete defect of the gastric wall in an animal model. In none of the animals tested either gastrointestinal complications or negative systemic events occurred, however, there was a multilayered regeneration of the gastric wall implying a regular structured mucosa.In future the advanced stem cell technology will allow further progress in the reconstruction of different kind of tissues also in the field of head and neck surgery following the principles of Tissue Engineering.

  10. Corrosion of bio implants

    Indian Academy of Sciences (India)

    U Kamachi Mudali; T M Sridhar; Baldev Raj

    2003-06-01

    Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in bone fractures and replacements. Corrosion is one of the major processes affecting the life and service of orthopaedic devices made of metals and alloys used as implants in the body. Among the metals and alloys known, stainless steels (SS), Co–Cr alloys and titanium and its alloys are the most widely used for the making of biodevices for extended life in human body. Incidences of failure of stainless steel implant devices reveal the occurrence of significant localised corroding viz., pitting and crevice corrosion. Titanium forms a stable TiO2 film which can release titanium particles under wear into the body environment. To reduce corrosion and achieve better biocompatibility, bulk alloying of stainless steels with titanium and nitrogen, surface alloying by ion implantation of stainless steels and titanium and its alloys, and surface modification of stainless steel with bioceramic coatings are considered potential methods for improving the performance of orthopaedic devices. This review discusses these issues in depth and examines emerging directions.

  11. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials.

    Science.gov (United States)

    Hofmann, F; Mason, D R; Eliason, J K; Maznev, A A; Nelson, K A; Dudarev, S L

    2015-11-03

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  12. Retardation of surface corrosion of biodegradable magnesium-based materials by aluminum ion implantation

    Science.gov (United States)

    Wu, Guosong; Xu, Ruizhen; Feng, Kai; Wu, Shuilin; Wu, Zhengwei; Sun, Guangyong; Zheng, Gang; Li, Guangyao; Chu, Paul K.

    2012-07-01

    Aluminum ion implantation is employed to modify pure Mg as well as AZ31 and AZ91 magnesium alloys and their surface degradation behavior in simulated body fluids is studied. Polarization tests performed in conjunction with scanning electron microscopy (SEM) reveal that the surface corrosion resistance after Al ion implantation is improved appreciably. This enhancement can be attributed to the formation of a gradient surface structure with a gradual transition from an Al-rich oxide layer to Al-rich metal layer. Compared to the high Al-content magnesium alloy (AZ91), a larger reduction in the degradation rate is achieved from pure magnesium and AZ31. Our results reveal that the surface corrosion resistance of Mg alloys with no or low Al content can be improved by Al ion implantation.

  13. In vitro and in vivo studies of ultrafine-grain Ti as dental implant material processed by ECAP.

    Science.gov (United States)

    An, Baili; Li, Zhirui; Diao, Xiaoou; Xin, Haitao; Zhang, Qiang; Jia, Xiaorui; Wu, Yulu; Li, Kai; Guo, Yazhou

    2016-10-01

    The aim of this study was to investigate the surface characterization of ultrafine-grain pure titanium (UFG-Ti) after sandblasting and acid-etching (SLA) and to evaluate its biocompatibility as dental implant material in vitro and in vivo. UFG-Ti was produced by equal channel angular pressing (ECAP) using commercially pure titanium (CP-Ti). Microstructure and yield strength were investigated. The morphology, wettability and roughness of the specimens were analyzed after they were modified by SLA. MC3T3-E1 osteoblasts were seeded onto the specimens to evaluate its biocompatibility in vitro. For the in vivo study, UFG-Ti implants after SLA were embedded into the femurs of New Zealand rabbits. Osseointegration was investigated though micro-CT analysis, histological assessment and pull-out test. The control group was CP-Ti. UFG-Ti with enhanced mechanical properties was produced by four passes of ECAP in BC route at room temperature. After SLA modification, the hierarchical porous structure on its surface exhibited excellent wettability. The adhesion, proliferation and viability of cells cultured on the UFG-Ti were superior to that of CP-Ti. In the in vivo study, favorable osseointegration occurred between the implant and bone in CP and UFG-Ti groups. The combination intensity of UF- Ti with bone was higher according to the pull-out test. This study supports the claim that UFG-Ti has grain refinement with outstanding mechanical properties and, with its excellent biocompatibility, has potential for use as dental implant material.

  14. The effect of shape, length and diameter of implants on primary stability based on resonance frequency analysis

    Directory of Open Access Journals (Sweden)

    Hamidreza Barikani

    2014-01-01

    Full Text Available Background: The aim of this in vitro study was to evaluate the effect of shape, diameter and length of implants on their primary stability based on resonance frequency analysis. Materials and Methods: Replace select tapered and Branemark MK III implants were selected. Each of these two selected groups was divided into nine subgroups based on the implant length (IL (short, medium and long and the implant diameter (ID (narrow platform [NP], regular platform [RP] and wide platform [WP]. Five implants were assigned to each of the nine subgroups. Implants were placed in artificial bone blocks with bone quality similar to D3 bone. Immediately after the implant placement, its primary stability was measured using Osstell Mentor equipment. T-test and Tukey′s honest significant difference Post hoc were performed for data analysis. Statistical significance was defined at P < 0.05. Results: Replace select system showed significantly higher primary stability compared to the Branemark system, when using the short implants for all three diameters (P ≤ 0.004. However, in medium length implants there were no significant differences between the two implant systems (P ≥ 0.31. In long implants, only when the NP and RP implants were used, the Replace Select system showed significantly higher primary stability compared to the Branemark system (P = 0.000. In the replace select system, long implants had a significantly higher primary stability compared to medium and short length implants (P ≤ 0.003. In the NP and RP Branemark implants, short implants showed significantly lower primary stability compared to medium and long implants (P ≤ 0.002. However, in WP Branemark implants, primary stability increased significantly with increasing the IL from short to medium and from medium to long (P = 0.000. There were also significant differences between NP and the two other wider implants in both systems (P = 0.000. Conclusion: The use of tapered implants is

  15. Performance of the Straumann Bone Level Implant system for anterior single-tooth replacements in augmented and nonaugmented sites : A prospective cohort study with 60 consecutive patients

    NARCIS (Netherlands)

    Santing, Hendrik J.; Raghoebar, Gerry M.; Vissink, Arjan; den Hartog, Laurens; Meijer, Henny J. A.

    2013-01-01

    Aim The purpose of this prospective study was to evaluate radiographic, clinical and aesthetic outcomes and patient satisfaction of cases treated with platform-switched single implant restorations in the aesthetic region of the maxilla. Furthermore, the influence of an augmentation procedure 3months

  16. Inflammation, NK cells and implantation: friend and foe (the good, the bad and the ugly?): replacing placental viviparity in an evolutionary perspective.

    Science.gov (United States)

    Chaouat, Gérard

    2013-03-01

    This review summarises an invited talk presented at the 2012 ESRI/ASRI meeting in Hamburg, concerning current views of inflammation in pregnancy, which is timely given that the effects of a local injury in the uterus acts to favour implantation. Recalling that inflammation can be good (it is useful and necessary for implantation), bad (in implantation failure, RSA) and ugly (at the extreme, endometriosis is associated with pain and infertility) leads to consideration of its status in pregnancy. Its role in implantation and the fact that pregnancy maintains some aspects of inflammation throughout, leads to revision of not only concepts of immunosuppression and the Th1/Th2 paradigm, but also the feto-maternal relationship as seen since Medawar's hypotheses were advanced. This is examined from an evolutionary perspective, which should lead to further review of our perception of uterine NK cells, and the emergence of Treg cells to control some aspects of adaptive immunity, which appeared long after placentation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Optimal Implantation Depth and Adherence to Guidelines on Permanent Pacing to Improve the Results of Transcatheter Aortic Valve Replacement With the Medtronic CoreValve System: The CoreValve Prospective, International, Post-Market ADVANCE-II Study.

    Science.gov (United States)

    Petronio, Anna S; Sinning, Jan-Malte; Van Mieghem, Nicolas; Zucchelli, Giulio; Nickenig, Georg; Bekeredjian, Raffi; Bosmans, Johan; Bedogni, Francesco; Branny, Marian; Stangl, Karl; Kovac, Jan; Schiltgen, Molly; Kraus, Stacia; de Jaegere, Peter

    2015-05-01

    The aim of the CoreValve prospective, international, post-market ADVANCE-II study was to define the rates of conduction disturbances and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement with the Medtronic CoreValve System (Minneapolis, Minnesota) using optimized implantation techniques and application of international guidelines on cardiac pacing. Conduction disturbances are a frequent complication of transcatheter aortic valve replacement. The rates of PPI in the published reports vary according to bioprosthesis type and the indications for PPI. The primary endpoint was the 30-day incidence of PPI with Class I/II indications when the Medtronic CoreValve System was implanted at an optimal depth (≤6 mm below the aortic annulus). The timing and resolution of all new-onset conduction disturbances were analyzed. A total of 194 patients were treated. The overall rate of PPI for Class I/II indications was 18.2%. An optimal depth was reached in 43.2% of patients, with a nonsignificantly lower incidence of PPI in patients with depths ≤6 mm, compared with those with deeper implants (13.3% vs. 21.1%; p = 0.14). In a paired analysis, new-onset left bundle branch block and first-degree atrioventricular block occurred in 45.4% and 39.0% of patients, respectively, and resolved spontaneously within 30 days in 43.2% and 73.9%, respectively. In patients with new PPI, the rate of intrinsic sinus rhythm increased from 25.9% at 7 days to 59.3% at 30 days (p = 0.004). Optimal Medtronic CoreValve System deployment and adherence to international guidelines on cardiac pacing are associated with a lower rate of new PPI after transcatheter aortic valve replacement, compared with results reported in previous studies. (CoreValve Advance-II Study: Prospective International Post-Market Study [ADVANCE II]; NCT01624870). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  18. 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.

  19. Electrostatic acceleration and deflection system for modification of semiconductor materials in laser-produced ion implantation

    Science.gov (United States)

    Rosinski, M.; Parys, P.; Wolowski, J.; Gasior, P.; Pisarek, M.

    2010-10-01

    To optimize the efficiency of laser ion implantation technology, it is advisable to properly select the laser beam characteristics (i.e. power density, target illumination geometry, etc.). In many applications, it is important to select a specific range of ion energy to implant the ions at a given depth and at a given density. To make it possible, the electrostatic system for acceleration and deflection of low-energy laser-produced ions can be used. This contribution provides a description of the experiments aimed at the implantation of Ge ions from a narrow energy band onto SiO2/Si substrates, which were conducted at IPPLM. As the source of irradiation, we used a Nd:YAG up to 10 Hz laser system with pulse duration of 3.5 ns and pulse energy ∼ 0.5 J, which gave a power density of 1010 W/cm2. The ion stream parameters were measured using the time-of-fight method. The laser-produced ions passing through the diaphragm have been accelerated in the system of electrodes. Due to the electrostatic field configuration provided by the electrode system and a diaphragm located at the axis of the system, the selected ions were focussed at the area of interest to increase implantation density. The accelerating voltage, the distance of the diaphragm from the target, the diaphragm diameter and the gap width between electrodes were changed for choosing the desired parameters of the ion stream.

  20. Electrochemical study of potential materials for cochlear implant electrode array (abstract)

    NARCIS (Netherlands)

    Lawand, N.S.; Lopez, V.; French, P.J.

    2013-01-01

    Cochlear implants (CIs) are commonly accepted therapeutic devices for clinical use and have restored hearing to more than 230,000 profoundly deaf people. CI devices consists of an external part comprising a speech processor (DSP) a microphone which together receive and convert the sound into a digit

  1. DEALING WITH DENTAL IMPLANT FAILURES

    Science.gov (United States)

    Levin, Liran

    2008-01-01

    An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options. When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them. PMID:19089213

  2. Dealing with dental implant failures

    Directory of Open Access Journals (Sweden)

    Liran Levin

    2008-06-01

    Full Text Available An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options.When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them.

  3. In Vitro Laser Treatment Platform Construction with Dental Implant Thread Surface on Bacterial Adhesion for Peri-Implantitis.

    Science.gov (United States)

    Kuo, Hsien-Nan; Mei, Hsiang-I; Liu, Tung-Kuan; Liu, Tse-Ying; Lo, Lun-Jou; Lin, Chun-Li

    2017-01-01

    This study constructs a standard in vitro laser treatment platform with dental implant thread surface on bacterial adhesion for peri-implantitis at different tooth positions. The standard clinical adult tooth jaw model was scanned to construct the digital model with 6 mm bone loss depth on behalf of serious peri-implantitis at the incisor, first premolar, and first molar. A cylindrical suite connected to the implant and each tooth root in the jaw model was designed as one experimental unit set to allow the suite to be replaced for individual bacterial adhesion. The digital peri-implantitis and suite models were exported to fulfill the physical model using ABS material in a 3D printer. A 3 mm diameter specimen implant on bacterial adhesion against Escherichia coli was performed for gram-negative bacteria. An Er:YAG laser, working with a chisel type glass tip, was moved from the buccal across the implant thread to the lingual for about 30 seconds per sample to verify the in vitro laser treatment platform. The result showed that the sterilization rate can reach 99.3% and the jaw model was not damaged after laser irradiation testing. This study concluded that using integrated image processing, reverse engineering, CAD system, and a 3D printer to construct a peri-implantitis model replacing the implant on bacterial adhesion and acceptable sterilization rate proved the feasibility of the proposed laser treatment platform.

  4. In Vitro Laser Treatment Platform Construction with Dental Implant Thread Surface on Bacterial Adhesion for Peri-Implantitis

    Directory of Open Access Journals (Sweden)

    Hsien-Nan Kuo

    2017-01-01

    Full Text Available This study constructs a standard in vitro laser treatment platform with dental implant thread surface on bacterial adhesion for peri-implantitis at different tooth positions. The standard clinical adult tooth jaw model was scanned to construct the digital model with 6 mm bone loss depth on behalf of serious peri-implantitis at the incisor, first premolar, and first molar. A cylindrical suite connected to the implant and each tooth root in the jaw model was designed as one experimental unit set to allow the suite to be replaced for individual bacterial adhesion. The digital peri-implantitis and suite models were exported to fulfill the physical model using ABS material in a 3D printer. A 3 mm diameter specimen implant on bacterial adhesion against Escherichia coli was performed for gram-negative bacteria. An Er:YAG laser, working with a chisel type glass tip, was moved from the buccal across the implant thread to the lingual for about 30 seconds per sample to verify the in vitro laser treatment platform. The result showed that the sterilization rate can reach 99.3% and the jaw model was not damaged after laser irradiation testing. This study concluded that using integrated image processing, reverse engineering, CAD system, and a 3D printer to construct a peri-implantitis model replacing the implant on bacterial adhesion and acceptable sterilization rate proved the feasibility of the proposed laser treatment platform.

  5. Wear study of Total Ankle Replacement explants by microstructural analysis.

    Science.gov (United States)

    Cottrino, S; Fabrègue, D; Cowie, A P; Besse, J-L; Tadier, S; Gremillard, L; Hartmann, D J

    2016-08-01

    The implantation of Total Ankle Replacement (TAR) prostheses generally gives satisfactory results. However, a high revision rate is associated with the Ankle Evolutive System (AES) implant, due to periprosthetic osteolysis that generates significant cortical lesions and bone cysts in the periprosthetic region. Radioclinical and histological analyses of peri-implant tissues show the presence of numerous foreign particles that may come from the implant. It is known that a precocious wear of materials may lead to an important rate of foreign body in tissues and may generate osteolysis lesions and inflammatory reactions. Thus the objectives of this retrospective study of 10 AES TAR implants (recovered after revision surgeries) are to understand how the prostheses wear out, which part is the most stressed and to determine the nature and size of foreign body particles. A better understanding of friction mechanisms between the three parts of the implant and of the nature and morphology of foreign particles generated was needed to explain the in vivo behavior of the implant. This was achieved using microstuctural and tomographic analysis of both implants parts and periprosthetic tissues.

  6. RAPID MANUFACTURING SYSTEM OF ORTHOPEDIC IMPLANTS

    Science.gov (United States)

    Relvas, Carlos; Reis, Joana; Potes, José Alberto Caeiro; Fonseca, Fernando Manuel Ferreira; Simões, José Antonio Oliveira

    2015-01-01

    This study, aimed the development of a methodology for rapid manufacture of orthopedic implants simultaneously with the surgical intervention, considering two potential applications in the fields of orthopedics: the manufacture of anatomically adapted implants and implants for bone loss replacement. This work innovation consists on the capitation of the in situ geometry of the implant by direct capture of the shape using an elastomeric material (polyvinylsiloxane) which allows fine detail and great accuracy of the geometry. After scanning the elastomeric specimen, the implant is obtained by machining using a CNC milling machine programmed with a dedicated CAD/CAM system. After sterilization, the implant is able to be placed on the patient. The concept was developed using low cost technology and commercially available. The system has been tested in an in vivo hip arthroplasty performed on a sheep. The time increase of surgery was 80 minutes being 40 minutes the time of implant manufacturing. The system developed has been tested and the goals defined of the study achieved enabling the rapid manufacture of an implant in a time period compatible with the surgery time. PMID:27004181

  7. In vitro and in vivo studies of ultrafine-grain Ti as dental implant material processed by ECAP

    Energy Technology Data Exchange (ETDEWEB)

    An, Baili; Li, Zhirui; Diao, Xiaoou [State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); National Clinical Research Center for Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Shannxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Xin, Haitao, E-mail: xhthmj@fmmu.edu.cn [State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); National Clinical Research Center for Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Shannxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Zhang, Qiang; Jia, Xiaorui; Wu, Yulu; Li, Kai [State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); National Clinical Research Center for Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Shannxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Guo, Yazhou [School of Aeronautics, Northwestern Polytechnical University, Xi' an 710032 (China)

    2016-10-01

    The aim of this study was to investigate the surface characterization of ultrafine-grain pure titanium (UFG-Ti) after sandblasting and acid-etching (SLA) and to evaluate its biocompatibility as dental implant material in vitro and in vivo. UFG-Ti was produced by equal channel angular pressing (ECAP) using commercially pure titanium (CP-Ti). Microstructure and yield strength were investigated. The morphology, wettability and roughness of the specimens were analyzed after they were modified by SLA. MC3T3-E1 osteoblasts were seeded onto the specimens to evaluate its biocompatibility in vitro. For the in vivo study, UFG-Ti implants after SLA were embedded into the femurs of New Zealand rabbits. Osseointegration was investigated though micro-CT analysis, histological assessment and pull-out test. The control group was CP-Ti. UFG-Ti with enhanced mechanical properties was produced by four passes of ECAP in B{sub C} route at room temperature. After SLA modification, the hierarchical porous structure on its surface exhibited excellent wettability. The adhesion, proliferation and viability of cells cultured on the UFG-Ti were superior to that of CP-Ti. In the in vivo study, favorable osseointegration occurred between the implant and bone in CP and UFG-Ti groups. The combination intensity of UF- Ti with bone was higher according to the pull-out test. This study supports the claim that UFG-Ti has grain refinement with outstanding mechanical properties and, with its excellent biocompatibility, has potential for use as dental implant material. - Highlights: • Yield strength and Vickers hardness of Ti are improved significantly after it is grain-refined by ECAP process. • The hierarchical micro-porous structure with superior wettability could be formed on the surface of ECAP Ti after SLA. • The results in vitro exhibited excellent cell biocompatibility of UFG-Ti after sandblasting and acid-etching. • The osseointegration between UFG-Ti implant and surrounding bone could

  8. The role of prosthetic abutment material on the stress distribution in a maxillary single implant-supported fixed prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Hugo Eduardo, E-mail: hugo.e.peixoto@hotmail.com [Implantology Team, Latin American Institute of Research and Education in Dentistry, Curitiba, Paraná (Brazil); Bordin, Dimorvan, E-mail: dimorvan_bordin@hotmail.com [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Del Bel Cury, Altair A., E-mail: altcury@fop.unicamp.br [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Silva, Wander José da, E-mail: wanderjose@fop.unicamp.br [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Faot, Fernanda, E-mail: fernanda.faot@gmail.com [Department of Restorative Dentistry, School of Dentistry, Federal University of Pelotas, Gonçalves Chaves, 457, 2nd floor, Pelotas, Rio Grande do Sul 96015-560 (Brazil)

    2016-08-01

    Purpose: Evaluate the influence of abutment's material and geometry on stress distribution in a single implant-supported prosthesis. Materials and Methods: Three-dimensional models were made based on tomographic slices of the upper middle incisor area, in which a morse taper implant was positioned and a titanium (Ti) or zirconia (ZrN) universal abutments was installed. The commercially available geometry of titanium (T) and zirconia (Z) abutments were used to draw two models, TM1 and ZM1 respectively, which served as control groups. These models were compared with 2 experimental groups were the mechanical properties of Z were applied to the titanium abutment (TM2) and vice versa for the zirconia abutment (ZM2). Subsequently, loading was simulated in two steps, starting with a preload phase, calculated with the respective friction coefficients of each materials, followed by a combined preload and chewing force. The maximum von Mises stress was described. Data were analyzed by two-way ANOVA that considered material composition, geometry and loading (p < 0.05). Results: Titanium and zirconia abutments showed similar von Mises stresses in the mechanical part of the four models. The area with the highest concentration of stress was the screw thread, following by the screw body. The highest stress levels occurred in screw thread was observed during the preloading phase in the ZM1 model (931 MPa); and during the combined loading in the TM1 model (965 MPa). Statistically significant differences were observed for loading, the material × loading interaction, and the loading × geometry interaction (p < 0.05). Preloading contributed for 77.89% of the stress (p < 0.05). There were no statistically significant differences to the other factors (p > 0.05). Conclusion: The screw was the piece most intensely affected, mainly through the preload force, independent of the abutment's material. - Highlights: • The abutment's screw was the most impaired piece of the

  9. Implantes mamarios en el plano subfascial en reemplazo del bolsillo subglandular: un cambio lógico Breast implants in the subfascial plane in replacement of the subglandular pocket: a logical change

    Directory of Open Access Journals (Sweden)

    O.D. Ventura

    2006-03-01

    Full Text Available Desde 1999 hemos cambiado el plano subglandular del bolsillo de los implantes mamarios por el plano subfascial (subaponeurótico. Este plano se halla por debajo de la fascia aponeurótica del músculo pectoral mayor, serrato, oblicuo lateral y recto anterior. Este artículo considera 150 casos implantados en este plano (subfascial. Se utilizaron prótesis de superficie texturada. El abordaje fue por una incisión periareolar inferior. En todos los pacientes se consiguió una excelente cobertura del implante, al igual que una forma y movilidad natural. En ningún caso se observó el desagradable ondulado de cuadrantes superiores, conocido como rippling. Cuatro de ellos presentaron procesos capsulares contráctiles grado II de Baker (2,6%. En el postoperatorio inmediato se registró menor edema y una recuperación más rápida de lo habitual, de acuerdo a nuestra experiencia con los otros procedimientos (submuscular y subglandular. Cuando la elección del bolsillo es subglandular, el plano subfascial parecería ser el lugar lógico de la colocación de los implantes mamarios.Since 1999, the subglandular plane of the pocket has been substituted in our practise for the subfascial (subaponeurotic plane in breast implants. This plane lies underneath the aponeurotic fascia of the pectoralis major , the serratus, the lateral oblique and the rectus anterior muscles. This article describes 150 patients with implants in the subaponeurotic plane and textured surface. Patients were approached through an inferior periareolar incision. Excellent coverage of the implant, as well as natural shape and mobility were achieved in all patients. No ondulation (rippling in the upper half of the breast has been observed. Four patients (2,6% had Baker grade II capsular contracture. In the immediate post-op, less edema and faster-than-usual recovery could be seen versus our experience with other (submuscular and subglandular procedures. When a subglandular pocket is the

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

    Institute of Scientific and Technical Information of China (English)

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

    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 or bacterial colonization. Co-culture models, in which tissue cells and bacteria battle simultaneously for estate on an implant surface, have been demonstrated to provide a better in vitro mimic of the clinical situation. Here we aim to compare the surface coverage by U2OS osteoblasts cells prior to and after challenge by two anaerobic sub-gingival pathogens in a co-culture model on differently modified titanium (Ti), titanium-zirconium (TiZr) alloys and zirconia surfaces. Monoculture studies with either U2OS osteoblasts or bacteria were also carried out and indicated significant differences in biofilm formation between the implant materials, but interactions with U2OS osteoblasts were favourable on all materials. Adhering U2OS osteoblasts cells, however, were significantly more displaced from differently modified Ti surfaces by challenging sub-gingival pathogens than from TiZr alloys and zirconia variants. Combined with previous work employing a co-culture model consisting of human gingival fibroblasts and supra-gingival oral bacteria, results point to a different material selection to stimulate the formation of a soft tissue seal as compared to preservation of osseointegration under the unsterile conditions of the oral cavity.

  11. 义眼座Ⅰ期置换术临床研究%Clinical study of the primary replacement of orbitai implant

    Institute of Scientific and Technical Information of China (English)

    宋斗; 尤媛; 高方; 高利雅

    2012-01-01

    Objective To explore the indications and methods of repìacerent of orbital implant which needed to be removed for various reasons.Methods 61 patients were implanted hydroxyapatite at the time of removing the orbital filler for various rexsons.Results Follow-up for 6 to 175 months,there were no secondary infection or implants extrusion.6 patients suffered from mild eyelid sinking.The rest patients'cosmesis were acceptable.Conclusion The hydroxyapatite can be implanted at the time of removing orbital filler for the patients who have no significant infection.%目的 探讨对因各种原因需取出原有眼窝填充物者行羟基磷灰石义眼座置换术的适应证和方法.方法 对61例伴原有眼窝填充物因各种原因需取出者同期植入羟基磷灰石义眼座.结果 随访6~175个月,无继发感染和植入物排出现象.6例出现轻度上睑凹陷,其余病例放置义眼片后外观满意.结论 无明显感染症状的需取出原眼眶填充物者,可以在取出眼眶填充物的同时植入羟基磷灰石义眼座.

  12. 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.

  13. Influence of the residual oxygen in the plasma immersion ion implantation (PI3) processing of materials

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, M., E-mail: ueda@plasma.inpe.br [Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP (Brazil); Silva, A.R.; Mello, Carina B. [Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP (Brazil); Silva, G. [Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP (Brazil); Instituto Tecnologico de Aeronautica, Sao Jose dos Campos, SP (Brazil); Reuther, H. [Institute of Ion Beam Physics and Materials Research, Forschungzentrum Dresden-Rossendorf, Dresden (Germany); Oliveira, V.S. [Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP (Brazil)

    2011-12-15

    In this work, we investigated the effects of the contaminants present in the vacuum chamber of the PI3 system, in particular, the residual oxygen, which results in the formation of the oxide compounds on the surface and hence is responsible for the high implantation energies required to achieve reasonably thick treated layers. We used a mass spectrometer (RGA) with a quadruple filter to verify the composition of the residual vacuum and pressure of the elements present in the chamber. Initially we found a high proportion of residual oxygen in a vacuum with a pressure of 1 Multiplication-Sign 10{sup -3} Pa. Minimizing the residual oxygen percentage in about 80%, by efficient cleaning of the chamber walls and by improving the gas feeding process, we mitigated the formation of oxides during the PI3 process. Therefore we achieved a highly efficient PI3 processing obtaining implanted layers reaching about 50 nm, even in cases such as an aluminum alloy, where is very difficult to nitrogen implant at low energies. We performed nitrogen PI3 treatment of SS304 and Al7075 using pulses of only 3 kV and 15 Multiplication-Sign 10{sup -6} s at 1 kHz with an operating pressure of 1 Pa.

  14. Bioceramic Coatings for Orthopaedic Implants

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Allison A.

    2003-11-02

    During the past century, man-made materials and devices have been developed to the point at which they have been used successfully to replace and/or restore function to diseased or damaged tissues. In the field of orthopaedics, the use of metal implants has significantly improved the quality of life for countless individuals. Critical factors for implant success include proper design, material selection, and biocompatibility. While early research focused on the understanding biomechanical properties of the metal device, recent work has turned toward improving the biological properties of these devices. This has lead to the introduction of calcium phosphate (CaP) bioceramics as a bioactive interface between the bulk metal impart and the surrounding tissue. The first calcium phosphate coatings where produced via vapor phase routes but more recently, there has been the emergence of solution based and biomimetic methods. While each approach has its own intrinsic materials and biological properties, in general CaP coatings have the promise to improve implant biocompatibility and ultimately implant longevity.

  15. Evaluación del osteocoral como material de implante en bolsas infraóseas de dientes multirradiculares

    Directory of Open Access Journals (Sweden)

    Tania Sotomayor Marín

    1999-12-01

    Full Text Available Se evalúa la eficacia del osteocoral como material de implante en el tratamiento de bolsas infraóseas en dientes multirradiculares. Se analizaron 14 pacientes que se dividieron en 2 grupos: el primero incluyó a 6 pacientes con un total de 12 defectos, los cuales se evaluaron hasta los 6 meses. El segundo, con 8 pacientes y 16 defectos, que se reevaluaron a los 12 y 24 meses. En los 2 grupos se incluyeron pacientes de ambos sexos, que fueron implantados con osteocoral (grupo estudio y con hidroxiapatita (grupo control. Se realizó reparación inicial que incluyó remoción de cálculo y pulido de la superficie dentaria, educación y motivación y evaluación del cepillado, que debía mostrar valores iguales o mayores del 80 % en la remoción de placa dentobacteriana. Posteriormente se realizó el implante mediante operación a colgajo. Se realizaron radiografías de control a los 14 días, 6 meses (para el primer grupo y 12 y 24 meses (para el segundo grupo. Se controló sistemáticamente la higiene bucal en ambos grupos. Se controlaron nuevamente los indicadores clínicos a los 6 meses para el primer grupo, y a los 12 y 24 meses para el segundo. Se observó una disminución estadísticamente significativa en el índice gingival, profundidad de la bolsa y movilidad dentaria para ambos materiales implantológicos, sin que se reportaran grandes diferencias entre éstos. Radiográficamente se observó la presencia de relleno en el defecto original, y no hubo reacciones locales adversas, por lo que se consideró efectivo el tratamiento.Effectiveness of osteocoral was assessed as material for implants at infraosseous pockets of multirooted teeth. 14 analised patients were divided into 2 groups: first, included 6 cases and 16 defects, which were evaluated ultil 6 months. Second, included 8 cases and 16 defects, evaluated at 12 and 24 months. In both groups, males and women, were included underwent to implants with osteocoral (study group and

  16. Implante de bioprótese aórtica "stentless" em pacientes com alterações do anel aórtico Aortic valve replacement with a stentless bioprosthesis in patients with weakened aortic annulus

    Directory of Open Access Journals (Sweden)

    Bayard Gontijo Filho

    1993-06-01

    Full Text Available Dezessete pacientes portadores de doença da valva aórtica associada a alterações estruturais do anel aórtico foram submetidos a implante de bioprótese aórtica "stentless" (Biocór: 8 pacientes eram portadores de endocardite bacteriana, sendo 3 em valva aórtica e 5 em próteses. Os demais pacientes eram portadores de próteses aórticas disfuncionantes. A técnica de implante foi basicamente a mesma, utilizandose dois níveis de sutura, sendo o primeiro ao nível do anel aórtico e o outro na parede aórtica. Em 11 pacientes a aorta ascendente foi ampliada com remendo de pericárdio bovino e 3 pacientes foram submetidos, também, a substituição valvar mitral. Houve 1 óbito hospitalar no 23º dia de pós-operatório por falência de múltiplos órgãos em 1 paciente portador de endocardite bacteriana e quadro de AVC pré-operatório. Dois pacientes necessitaram implante de marcapasso definitivo. Na evolução tardia houve apenas 1 óbito no 6º mês, de forma súbita, em uma criança portadora de marcapasso. Um paciente desenvolveu deiscência parcial da bioprótese na sutura inferior, o que gerou um gradiente na via de saída do ventrículo esquerdo, sendo reoperado com sucesso de 18º mês de pós-operatório. Todos os pacientes encontram-se em controle ambulatorial, com estudos ecocardiográficos seriados, que demonstram excelente desempenho da bioprótese "stentless" sem gradientes transvalvares importantes e ausência de regurgitação aórtica significativa.An aortic stentless bioprosthesis (Biocor Ind. was implanted in 17 patients with difficult aortic annulus due either to endocarditis orto a previous aortic valve replacement. Native valve endocarditis was present in 3 patients and prosthetic valve endocarditis in 5; 9 patients had one or more previous aortic valve replacements showing a wheakened aortic rim. The stentless bioprosthesis was implanted with a two layers suture technique similar to a homograft implant. The

  17. USE OF PLASTIC MATERIAL AND TRIPLE SCAN IN THE PREPARATION OF SURGICAL GUIDES FOR THE DENTAL IMPLANT TREATMENT-CASE REPORT

    Directory of Open Access Journals (Sweden)

    Rosen Borisov

    2016-09-01

    Full Text Available The use of surgical guides in implant treatment increases the accuracy of the dental implant positioning compared with manual methods. Regardless of how they are made, deviations of implants from their intended position are established in all kinds of surgical guides. This article considers the use of plastic material and new scanning technique for the production of CAD/CAM surgical guides that aim to overcome the deficiencies of the currently applied technologies in the production of surgical guides. Materials and methods: The study shows the techniques used to overcome degraded by metal artifacts CBCT images in implant treatment of patients with partial edentulism, and located medially to the defect metal-ceramic crowns. When planning implant treatment, a triple scan method has been implied. At the beginning, CBCT scan of the patient with a silicone impression material is made in the zone of interest. Secondly, CBCT scan only of the silicon impression is made, and thirdly - intraoral scanning of the patient with an intraoral scanner. Virtual analogues have been created of images from the three scans and have been repositioned one over another; as thereby an intraoral image have been accurately positioned over the CBCT image of the patient. Virtual planning of the implant positioning has been performed, and a model of surgical guide has been made for their placement. The guide has been printed with an SLA 3D printer technology of photopolymer with dualistic characteristics-rigid in the working part and plastic in the fixing part. Through it, implants have been placed to the treatment planning. Postoperative CBCT has been done on the patient to measure the implant deviation to their position in the treatment planning. Results: Axes angular deviation of the planned and placed implants has not been established. Average linear displacement of 240 μ (+/- 40 μ has been found. Conclusions: Using the triple scan method is possible to overcome the

  18. Titanium coated with functionalized carbon nanotubes--a promising novel material for biomedical application as an implantable orthopaedic electronic device.

    Science.gov (United States)

    Przekora, Agata; Benko, Aleksandra; Nocun, Marek; Wyrwa, Jan; Blazewicz, Marta; Ginalska, Grazyna

    2014-12-01

    The aim of the study was to fabricate titanium (Ti) material coated with functionalized carbon nanotubes (f-CNTs) that would have potential medical application in orthopaedics as an implantable electronic device. The novel biomedical material (Ti-CNTs-H2O) would possess specific set of properties, such as: electrical conductivity, non-toxicity, and ability to inhibit connective tissue cell growth and proliferation protecting the Ti-CNTs-H2O surface against covering by cells. The novel material was obtained via an electrophoretic deposition of CNTs-H2O on the Ti surface. Then, physicochemical, electrical, and biological properties were evaluated. Electrical property evaluation revealed that a Ti-CNTs-H2O material is highly conductive and X-ray photoelectron spectroscopy analysis demonstrated that there are mainly COOH groups on the Ti-CNTs-H2O surface that are found to inhibit cell growth. Biological properties were assessed using normal human foetal osteoblast cell line (hFOB 1.19). Conducted cytotoxicity tests and live/dead fluorescent staining demonstrated that Ti-CNTs-H2O does not exert toxic effect on hFOB cells. Moreover, fluorescence laser scanning microscope observation demonstrated that Ti-CNTs-H2O surface retards to a great extent cell proliferation. The study resulted in successful fabrication of highly conductive, non-toxic Ti-CNTs-H2O material that possesses ability to inhibit osteoblast proliferation and thus has a great potential as an orthopaedic implantable electronic device. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Urinary incontinence - collagen implants

    Science.gov (United States)

    ... gov/ency/article/007373.htm Urinary incontinence - injectable implant To use the sharing features on this page, please enable JavaScript. Injectable implants are injections of material into the urethra to ...

  20. In situ heart valve tissue engineering using a bioresorbable elastomeric implant - From material design to 12 months follow-up in sheep.

    Science.gov (United States)

    Kluin, Jolanda; Talacua, Hanna; Smits, Anthal I P M; Emmert, Maximilian Y; Brugmans, Marieke C P; Fioretta, Emanuela S; Dijkman, Petra E; Söntjens, Serge H M; Duijvelshoff, Renée; Dekker, Sylvia; Janssen-van den Broek, Marloes W J T; Lintas, Valentina; Vink, Aryan; Hoerstrup, Simon P; Janssen, Henk M; Dankers, Patricia Y W; Baaijens, Frank P T; Bouten, Carlijn V C

    2017-05-01

    The creation of a living heart valve is a much-wanted alternative for current valve prostheses that suffer from limited durability and thromboembolic complications. Current strategies to create such valves, however, require the use of cells for in vitro culture, or decellularized human- or animal-derived donor tissue for in situ engineering. Here, we propose and demonstrate proof-of-concept of in situ heart valve tissue engineering using a synthetic approach, in which a cell-free, slow degrading elastomeric valvular implant is populated by endogenous cells to form new valvular tissue inside the heart. We designed a fibrous valvular scaffold, fabricated from a novel supramolecular elastomer, that enables endogenous cells to enter and produce matrix. Orthotopic implantations as pulmonary valve in sheep demonstrated sustained functionality up to 12 months, while the implant was gradually replaced by a layered collagen and elastic matrix in pace with cell-driven polymer resorption. Our results offer new perspectives for endogenous heart valve replacement starting from a readily-available synthetic graft that is compatible with surgical and transcatheter implantation procedures. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Deposition of TiC film on titanium for abrasion resistant implant material by ion-enhanced triode plasma CVD

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Yuhe, E-mail: zyh1120@hotmail.co.jp [School of Stomatology, China Medical University, Shen Yang (China); Wang Wei; Jia Xingya [School of Stomatology, China Medical University, Shen Yang (China); Akasaka, Tsukasa [Department of Health Science, School of Dental Medicine Hokkaido University, Sapporo (Japan); Liao, Susan [School of Materials Science and Engineering, Nanyang Technological University (Singapore); Watari, Fumio [Department of Health Science, School of Dental Medicine Hokkaido University, Sapporo (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Deposition of Titanium Carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method. Black-Right-Pointing-Pointer The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance. Black-Right-Pointing-Pointer Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. - Abstract: Deposition of titanium carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method using a TiCl{sub 4} + CH{sub 4} + H{sub 2} gas mixture. Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. X-ray diffraction (XRD) showed that the specimen was consisted of TiC and Ti. Carbide layer of about 6 {mu}m thickness was observed on the cross section of the specimen by scanning electron microscopy (SEM). The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance.

  2. Nanostructured severe plastic deformation processed titanium for orthodontic mini-implants.

    Science.gov (United States)

    Serra, Glaucio; Morais, Liliane; Elias, Carlos Nelson; Semenova, Irina P; Valiev, Ruslan; Salimgareeva, Gulnaz; Pithon, Matheus; Lacerda, Rogério

    2013-10-01

    Titanium mini-implants have been successfully used as anchorage devices in Orthodontics. Commercially pure titanium (cpTi) was recently replaced by Ti-6Al-4V alloy as the mini-implant material base due to the higher strength properties of the alloy. However, the lower corrosion resistance and the lower biocompatibility have been lowering the success rate of Ti-6Al-4V mini-implants. Nanostructured titanium (nTi) is commercially pure titanium that was nanostructured by a specific technique of severe plastic deformation. It is bioinert, does not contain potentially toxic or allergic additives, and has higher specific strength properties than any other titanium applied in medical implants. The higher strength properties associated to the higher biocompatibility make nTi potentially useful for orthodontic mini-implant applications, theoretically overcoming cpTi and Ti-6Al-4V mini-implants. The purposes of the this work were to process nTi, to mechanically compare cpTi, Ti-6Al-4V, and nTi mini-implants by torque test, and to evaluate both the surface morphology and the fracture surface characteristics of them by SEM. Torque test results showed significant increase in the maximum torque resistance of nTi mini-implants when compared to cpTi mini-implants, and no statistical difference between Ti-6Al-4V and nTi mini-implants. SEM analysis demonstrated smooth surface morphology and transgranular fracture aspect for nTi mini-implants. Since nanostructured titanium mini-implants have mechanical properties comparable to titanium alloy mini-implants, and biocompatibility comparable to commercially pure titanium mini-implants, it is suggestive that nanostructured titanium can replace Ti-6Al-4V alloy as the material base for mini-implants.

  3. Quantification of ion or atom transfer phenomena in materials implanted by nuclear methods; Quantification de phenomenes de transferts ioniques ou atomiques dans des materiaux implantes par la mise en oeuvre de methodes nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Oudadesse, Hassane [Clermont-Ferrand-2 Univ., 63 - Aubiere (France)

    1998-05-18

    Knowledge of transfer of the constituents of a system from regions of higher to lower concentration is of interest for implanted bio-materials. It allows determining the rate at which this material is integrated in a living material. To evaluate the ossification kinetics and to study the bio-functionality in corals of Ca and Sr, irradiations with a 10{sup 13} n.cm{sup -2}.s{sup -1} was performed, followed by the examination of changes in the localization of these elements. By using PIXE analysis method the distribution of Ca, P, Sr, Zn and Fe in the implant, bone and bone-implant interfaces were determined. Thus, it was shown that resorption of coral in sheep is achieved in 5 months after implantation and is identical to the cortical tissues 4 months after implantation in animals as for instance in hares. We have analyzed the tissues from around the prostheses extracted from patients. The samples were calcined and reduced to powder weighting some milligrams. We have adopted for this study the PIXE analysis method. The samples were irradiated by a proton beam of 3 MeV and about 400 {mu}m diameter. The results show the presence of the elements Ti, Fe, Cr, Ni or Zn according to the type of the implanted prosthesis. This dispersal of the metallic ions and atoms contaminate the tissues. The transfer factors translate the exchanges between bone and the implanted material. The solvatation phenomenon and the electric charge equilibrium explain the transfer order of cations Mg{sup 2+}, Ca{sup 2+} and Sr{sup 2+} and of the anion PO{sub 4}{sup 3-}. We have also determined these factors for the elements Ti, Cr and Ni. An original technique to study the bone bio-functionality was used. Use of phosphate derivatives labelled by {sup 99m}Tc allows obtaining information about the fixation of radioactive tracer. It was found that only after the eighth month at the implantation the neo-formed bone fixes the MDP (methyl diphosphate) labelled by {sup 99m}Tc in a similar way as in the

  4. The effect of different restorative and abutment materials on marginal and internal adaptation of three-unit cantilever implant-supported fixed partial dentures: an in vitro study.

    Science.gov (United States)

    Kahramanoğlu, Erkut; Kulak-Özkan, Yasemin

    2013-12-01

    Passive fit is generally assumed to be a significant prerequisite for long-term implant success. The aim of this study was to evaluate the precision fit of three-unit implant-supported fixed partial dentures with different restorative and abutment materials on two implant systems: the Straumann and Astra Tech. Two mandibular epoxy resin models (one for each implant system) were fabricated, and two implants were inserted at the first and second molar region. Poly(vinyl siloxane) impression material was used to make the dental impression. For each implant system, fifteen models were fabricated, and each group was divided into three subgroups (group 1: titanium abutment with metal framework, group 2: titanium abutment with zirconium framework, group 3: zirconium abutment with zirconium framework). The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, totaling 1200 measurements for all groups. Data were evaluated statistically using ANOVA and LSD post hoc test (p study, marginal measurement values were found to be 46 to 87 μm. The marginal discrepancy of the tested materials could be considered clinically acceptable. © 2013 by the American College of Prosthodontists.

  5. Evaluation of Guided Bone Regeneration around Oral Implants over Different Healing Times Using Two Different Bovine Bone Materials: A Randomized, Controlled Clinical and Histological Investigation.

    Science.gov (United States)

    Kohal, Ralf Joachim; Straub, Lisa Marie; Wolkewitz, Martin; Bächle, Maria; Patzelt, Sebastian Berthold Maximilian

    2015-10-01

    To evaluate the potential of two bone substitute materials and the influence of different healing periods in guided bone regeneration therapy of osseous defects around implants. Twenty-four edentulous patients received implants in the region of the lost lower incisors. Around two standardized osseous defects were created, treated either with a 50:50 mixture of PepGen P-15® and OsteoGraf®/N-700 (test group) or with BioOss® (control group), and covered with titanium membranes. After healing periods of 2, 4, 6, or 9 months, the implants were removed together with the surrounding bone and subsequently prepared for histological evaluations. Defect depths in both groups showed a clinical reduction after intervention. The histologically measured distance from the implant shoulder to the first point of bone-implant contact (BIC) after treatment did not differ between the two groups. The healing time influenced the level of the first point of BIC, with a longer healing period producing a more coronal first point of BIC. A greater percentage BIC and a higher fraction of mineralized bone were found in the pristine bone area compared with the augmented defect area. It can be concluded that in the treatment of osseous defects around oral implants, both materials were equally effective bone substitute materials when used in combination with guided bone regeneration. © 2014 Wiley Periodicals, Inc.

  6. Implants in adolescents.

    Science.gov (United States)

    Shah, Rohit A; Mitra, Dipika K; Rodrigues, Silvia V; Pathare, Pragalbha N; Podar, Rajesh S; Vijayakar, Harshad N

    2013-07-01

    Implants have gained tremendous popularity as a treatment modality for replacement of missing teeth in adults. There is extensive research present on the use of implants in adults, but there is a dearth of data available on the same in adolescents. The treatment planning and execution of implant placement in adolescents is still in its infancy. This review article is an attempt to bring together available literature.

  7. Implants in adolescents

    Directory of Open Access Journals (Sweden)

    Rohit A Shah

    2013-01-01

    Full Text Available Implants have gained tremendous popularity as a treatment modality for replacement of missing teeth in adults. There is extensive research present on the use of implants in adults, but there is a dearth of data available on the same in adolescents. The treatment planning and execution of implant placement in adolescents is still in its infancy. This review article is an attempt to bring together available literature.

  8. PEEK and CFR-PEEK as alternative bearing materials to UHMWPE in a fixed bearing total knee replacement: An experimental wear study.

    Science.gov (United States)

    Brockett, Claire L; Carbone, Silvia; Fisher, John; Jennings, Louise M

    2017-03-15

    New bearing materials for total joint replacement have been explored as the need to improve longevity and enhance performance is driven by the changing demands of the patient demographic. Carbon-reinforced PEEK has demonstrated good wear characteristics in experimental wear simulation in both simple geometry pin-on-plate studies and in total hip joint replacement. Carbon reinforced PEEK CFR-PEEK has the potential to reduce tibial insert thickness and preserve bone in the knee. This study investigated the wear performance of PEEK and CFR-PEEK in a low conformity total knee replacement configuration. Custom-made flat inserts were tested against cobalt-chromium femoral bearings in a knee wear simulation for a period of three million cycles. Wear was assessed gravimetrically at intervals throughout the study. The wear rates of both PEEK and CFR-PEEK were very high and almost two orders of magnitude higher than the wear rate of UHMWPE under comparable conditions. Evidence of mechanical failure of the materials, including surface cracking and delamination was observed in both materials. This study highlights that these materials may not be suitable alternatives for UHMWPE in low-conformity designs.

  9. In Vitro Comparative Evaluation of Different Types of Impression Trays and Impression Materials on the Accuracy of Open Tray Implant Impressions: A Pilot Study.

    Science.gov (United States)

    Gupta, Sonam; Narayan, Aparna Ichalangod; Balakrishnan, Dhanasekar

    2017-01-01

    Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique. Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n = 5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA. Results. Statistically significant difference (p materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p > 0.05) was observed between varied stock and custom trays. Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials.

  10. Mucosal topography around implants in edentulous upper jaws. Photogrammetric three-dimensional measurements of the effect of replacement of a removable prosthesis with a fixed prosthesis.

    Science.gov (United States)

    Jemt, T; Book, K; Lie, A; Börjesson, T

    1994-12-01

    A photogrammetric technique was tested to measure the topography of the mucosa around implants, placed in edentulous upper jaws. Photographs were taken of casts from 6 patients, who all had used a removable overdenture for one year. Another series of photographs was taken on new casts after the use of a fixed prosthesis for a second year. The 6 pairs of photographs were measured and compared in an analytical stereo plotter for surface contour and implant positions. The results from the measurements indicated a trend of general recession of the mucosa after one year with fixed prosthesis, both on the buccal as well as on the palatal side. The mean volume of recession was 222.4 mm3, corresponding to an average of 0.4 mm3/mm2 of mucosa. More recession was generally observed on the palatal side, but obvious variations between the patients were present. In conclusion, the photogrammetric technique was considered to be well suited for analysing tissue contours in various dental situations.

  11. Clinical evaluation of mandibular implant overdentures via Locator implant attachment and Locator bar attachment

    Science.gov (United States)

    Seo, Yong-Ho; Bae, Eun-Bin; Kim, Jung-Woo; Lee, So-Hyoun; Jeong, Chang-Mo; Jeon, Young-Chan

    2016-01-01

    PURPOSE The aim of this study was to evaluate the clinical findings and patient satisfaction on implant overdenture designed with Locator implant attachment or Locator bar attachment in mandibular edentulous patients. MATERIALS AND METHODS Implant survival rate, marginal bone loss, probing depth, peri-implant inflammation, bleeding, plaque, calculus, complications, and satisfaction were evaluated on sixteen patients who were treated with mandibular overdenture and have used it for at least 1 year (Locator implant attachment: n=8, Locator bar attachment: n=8). RESULTS Marginal bone loss, probing depth, plaque index of the Locator bar attachment group were significantly lower than the Locator implant attachment group (P.05). The replacement of the attachment components was the most common complication in both groups. Although there was no correlation between marginal bone loss and plaque index, a significant correlation was found between marginal bone loss and probing depth. CONCLUSION The Locator bar attachment group indicates lesser marginal bone loss and need for maintenance, as compared with the Locator implant attachment group. This may be due to the splinting effect among implants rather than the types of Locator attachment. PMID:27555901

  12. Bioceramic dip-coating on Ti-6Al-4V and 316L SS implant materials.

    Science.gov (United States)

    Aksakal, Bunyamin; Hanyaloglu, C

    2008-05-01

    The focus of the present study is based on more economical and rapid bioceramic coating on the most common implant substrates such as Ti-6Al-4V and 316L SS used often in orthopedics. For ceramic dip coating of implant substrates, Hydroxyapatite (HA) powder, Ca10(PO4)6(OH)2, P2O5, Na2CO3 and KH2PO4 are used to provide the gel. Ceramic films on sandblasted substrates have been deposited by using a newly manufactured dip-coating apparatus. Sample characterization is evaluated by SEM and XRD analysis. A smooth and homogeneous coating films have been obtained and average of 20 MPa bonding strength has been achieved for both Ti-6Al-4V and 316L SS alloys after sintering at 750 degrees C under flowing argon. The level of importance of the process parameters on coating was determined by using analysis of variance (ANOVA). The current process appears to be cheap, easy, and flexible to shape variations and high production rates for orthopedic applications.

  13. Low-cost ion implantation and annealing technology for solar cells

    Science.gov (United States)

    Kirkpatrick, A. H.; Minnucci, J. A.; Greenwald, A. C.

    1980-01-01

    Ion implantation and thermal annealing techniques for processing junctions and back surface layers in solar cells are discussed. Standard 10 keV (31)p(+) junction implants and 25 keV (11)B(+) back surface implants in combination with three-step furnace annealing are used for processing a range of silicon materials and device structures. Cells with efficiencies up to 16.5% AM1 are being produced, and large-area terrestrial cells with implanted junctions and back fields being fabricated in pilot production exhibit average efficiencies in excess of 15% AM1. Thermal annealing methods for removal of the radiation damage caused by implantation should be replaced by transient processing techniques in future production. Design studies have been completed for solar cell processing implanters to support 10 MW/yr and 100 MW/yr production lines, and analyses indicate that implantation costs can be reduced to approximately 1 cent/watt.

  14. Provisional anterior tooth replacement using nonimpregnated fiber and fiber-reinforced composite resin materials: a clinical report.

    Science.gov (United States)

    Chan, Daniel C N; Giannini, Marcelo; De Goes, Mario Fernando

    2006-05-01

    The loss of anterior teeth is often a serious esthetic concern. While conventional fixed partial dentures and implant-supported restorations may be the treatments of choice, nonimpregnated fibers (NFs) and fiber-reinforced composite (FRC) resins offer a conservative alternative for improving esthetics. This article describes 2 clinical situations in which NF glass ribbon and FRC were successfully used to provisionally restore anterior edentulous areas in an esthetic, functional, and timely manner.

  15. The surgical cooperation and nurse strategy in total arch replacement combined with stented elephant trunk implantation%主动脉全弓置换联合支架象鼻手术的手术配合及护理

    Institute of Scientific and Technical Information of China (English)

    印建榕

    2011-01-01

    Objective To explore the surgical cooperation with traveling nurse in total arch replacement combined with stented elephant trunk implantation for Stanford A aortic dissection, and discuss the nursing strategy in perioperative. Methods The effect of tour nursing with 15 patients who were operated total arch replacement combined with stented elephant trunk implantation in cardiopulmonary bypass, and how to collaborate with traveling nurse better were analyzed. Results All the cases were operated successfully, the cooperation between instrument nurse and traveling nurse were very good, the patients returned to intensive care unit safely after operation. Conclusion The nurse should acquaint the information of patients before operation, know the process of surgery, get fully prepared before surgery, to ensure the surgical process to go smoothly.%目的 探讨主动脉全弓置换联合支架象鼻术治疗主动脉夹层的手术配合及护理.方法 分析15例在体外循环下行主动脉全弓置换联合支架象鼻术手术的器械配合及巡回护理的效果.结果 本组病例均顺利完成手术,术中器械及巡回护士配合达到预期的效果,患者术后安返监护室.结论 手术室护士术前必须充分了解患者的病情,熟悉手术操作过程,做好术前各种准备,术中才能配合默契,有利于手术的顺利进行.

  16. Substituição dos ligamentos cruzados cranial e caudal em cães por duplo implante de polipropileno Replacement of the cranial and caudal cruciate ligaments in dogs by double t polypropylene implant

    OpenAIRE

    Daniel Curvello de Mendonça Müller; Paula Cristina Basso; Gabriele Maria Callegaro Serafini; Maurício Borges da Rosa; Arícia Gomes Sprada; João Paulo Monteiro Carvalho Mori da Cunha; Ney Luis Pippi

    2011-01-01

    O objetivo deste trabalho é salientar uma alternativa eficaz no tratamento da ruptura dos ligamentos cruzados cranial e caudal de cães, sem associação de imobilização externa. Foram atendidos seis animais portadores de ruptura de ambos os ligamentos cruzados. Optou-se pela correção cirúrgica intracapsular, utilizando-se dois implantes sintéticos de polipropileno, para a estabilização da articulação. Os pacientes retornaram ao apoio completo do membro em 11,8±3,5 dias e não mantiveram i...

  17. Application and safety evaluation of different dental implant materials%不同口腔种植材料的应用及安全性评价

    Institute of Scientific and Technical Information of China (English)

    宣永华

    2011-01-01

    背景:目前临床应用的牙种植体材料种类繁多,各有其优缺点,哪种材料更具临床应用价值及良好的生物相容性呢? 目的:综述不同口腔种植材料的研究进展,评价其种植后与宿主的相容性及临床应用前景.方法:应用计算机检索CNKI和PubMed数据库中2000-01/2011-03关于口腔种植材料应用的文章,在标题和摘要中以"口腔种植体;牙种植体;合金;陶瓷;高分子材料;复合材料"或"dental implant;polymer alloy composite material;ceramic/aluminum alloy"为检索词进行检索.选择内容与不同口腔种植材料的应用特点及安全性相关文章.初检得到126篇文献,根据纳入标准选择30篇文章进行综述.结果与结论:合金、陶瓷、高分子、复合材料及纳米材料在口腔种植方面发挥了重要作用.理想口腔植入材料的选择,需要对其生物相容性、生物力学性能、生物学形态、与周围组织的结合能力等各方面综合考虑,对细胞、组织等应无毒性、无刺激性、无致畸致突变性,同时与骨组织之间应形成骨性结合,具有良好的骨引导或骨诱导作用.%BACKGROUND: Currently, clinical dental implant materials are various with their own advantages and disadvantages, which one is better in clinical application and has good biocompatibility?OBJECTIVE: To review the progress of different dental implant materials and to evaluate the compatibility of dental implants with the host as well as their clinical prospect.METHODS: CNKI and PubMed (2000-01/2011-03) were retrieved for articles addressing application of dental implant materials using the keywords of “dental implant; polymer alloy composite material; ceramic/aluminum alloy” in English and “dental implant;tooth implant; alloy; ceramic; polymer material; composite material” in Chinese. Articles about application characteristics of different dental implant materials and their safety were retrieved and 126 articles were found

  18. Development of optimized epoxy graphite implant for the total hip joint.

    Science.gov (United States)

    Iyer, L S; Jayasekaran, T; Blunck, C F; Selvam, R P

    1984-01-01

    Various metal implants are available for total hip joint replacements. There are problems associated with the micromovement of the implants with bone and/or with bone cement and about ten percent failure cases are reported. The mechanical properties of the metal implants do not match with that of human bone in the femur resulting in a stress distribution in the femur different from one without implant. Many researchers are working with different materials like alloy materials with lower modulus of elasticity, ceramic, etc. The study conducted at S.D.S.M. & T. biomechanics laboratory investigates the feasibility of using epoxy graphite as an implant material. The mechanical properties of the implant material are being optimized using experimental and analytical methods. The reflection polariscope method (photo stress method) was used to determine the micromovement of the implant and the bone, and stress distribution in the femur subjected to cyclic loading. A finite element method was used to optimize the mechanical properties of the implant to obtain a stress distribution closer to the one without implant. An epoxy graphite implant with optimized mechanical properties is being manufactured and tests are in progress.

  19. Characteristics of Bone Tissue and Composite Materials on the Basis of Natural Hydroxyapatite and Endodontic Cement for Replacement of the Tissue

    Science.gov (United States)

    Filipenkov, V. V.; Rupeks, L. E.; Vitins, V. M.; Knets, I. V.; Kasyanov, V. A.

    2017-07-01

    New biocomposites and the cattle bone tissue were investigated. The composites were made from an endodontic cement (EC) and natural hydroxyapatite (NHAp.) The results of experiments performed by the method of infrared spectroscopy showed that protein was removed from the heat-treated specimens of bone tissue practically completely. The structure of bone tissue before and after deproteinization and the structure of the composite materials based on NHAp and EC (with different percentage) were investigated by the method of optical microscopy. The characteristics of mechanical properties (the initial elastic modulus, breaking tensile and compressive stresses, and breaking strain) and the density and porosity of these materials were determined. The new composite materials were implanted in the live tissue of rat. Biocompatibility between the live tissue and the new biocomposites was estimated.

  20. Degradable magnesium-based implant materials with anti-inflammatory activity.

    Science.gov (United States)

    Peng, Qiuming; Li, Kun; Han, Zengsheng; Wang, Erde; Xu, Zhigang; Liu, Riping; Tian, Yongjun

    2013-07-01

    The objective of this study was to prepare a new biodegradable Mg-based biomaterial, which provides good mechanical integrity in combination with anti-inflammatory function during the degradation process. The silver element was used, because it improved the mechanical properties as an effective grain refiner and it is also treated as a potential anti-inflammatory core. The new degradable Mg-Zn-Ag biomaterial was prepared by zone solidification technology and extrusion. The mechanical properties were mostly enhanced by fine grain strengthening. In addition, the alloys exhibited good cytocompatibility. The anti-inflammatory function of degradation products was identified by both interleukin-1α and nitric oxide modes. The anti-inflammatory impact was significantly associated with the concentration of silver ion. It was demonstrated that Mg-Zn-Ag system was a potential metallic stent with anti-inflammatory function, which can reduce the long-term dependence of anti-inflammatory drug after coronary stent implantation.

  1. Sol-gel synthesis and characterization of SiO2/PCL hybrid materials containing quercetin as new materials for antioxidant implants.

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando; Piccolella, Simona; Pacifico, Severina

    2016-01-01

    The development of biomaterials with intrinsic antioxidant properties could represent a valuable strategy for preventing peri-implant disease onset. In this context quercetin, a naturally occurring flavonoid, has been entrapped, at different weight percentages in a silica/poly(ε-caprolactone)-based hybrid material by a sol-gel route. FT-IR and UV spectroscopic techniques were employed in order to characterize the hybrids. FT-IR analysis indicated changes in stretching frequencies of the quercetin dienonic moiety, suggesting that a flavonol oxidized derivative was formed during the sol-gel process. The establishment of hydrogen-bonded interactions between quercetin and silica and polymer matrices,was strongly affected by the amount of polymer. Poly(ε-caprolactone) did not interact with quercetin when it was loaded at high doses (50 wt.%). The morphology of the synthesized materials was observed by using SEM. The obtained images proved that the materials are hybrid nanocomposites. Their bioactivity was shown by the formation of a hydroxyapatite layer on samples' surface soaked in a fluid simulating the composition of the human plasma. The antiradical properties of the investigated systems were evaluated by DPPH and ABTS methods and their cytotoxicity by the MTT assay. Data obtained revealed that the synthesized materials are biocompatible and that the hybrid system,with 6 wt.% of PCL and 15 wt.% of quercetin, produced the strongest antiradical efficacy.

  2. Ankle replacement

    Science.gov (United States)

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... You may not be able to have a total ankle replacement if you have had ankle joint infections in ...

  3. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  4. Laser and electron‐beam powder‐bed additive manufacturing of metallic implants: A review on processes, materials and designs

    National Research Council Canada - National Science Library

    Sing, Swee Leong; An, Jia; Yeong, Wai Yee; Wiria, Florencia Edith

    2016-01-01

    ...) and electron beam melting (EBM) are presented. Several critical design factors such as the need for data acquisition for patient-specific design, design dependent porosity for osteo-inductive implants, surface topology of the implants and design...

  5. A Dual-beam Implanter for Research of Material Irradiation Effect

    Institute of Scientific and Technical Information of China (English)

    TANG; Bing; CUI; Bao-qun; MA; Ying-jun; MA; Rui-gang; CHEN; Li-hua; HUANG; Qing-hua; MA; Xie

    2015-01-01

    With the development of reactor technology,the researches on the effect of material irradiation are becoming more and more interesting and expanding.To understand and model the aging caused by atomic displacements,helium and hydrogen production,material scientists and reactor

  6. Mechanisms by which a lack of germinal vesicle (GV) material causes oocyte meiotic defects: a study using oocytes manipulated to replace GV with primary spermatocyte nuclei.

    Science.gov (United States)

    Zhang, Jie; Cui, Wei; Li, Qing; Wang, Tian-Yang; Sui, Hong-Shu; Wang, Jun-Zuo; Luo, Ming-Jiu; Tan, Jing-He

    2013-10-01

    Oocytes with germinal vesicles (GVs) replaced with somatic nuclei exhibit meiotic abnormalities. Although this suggests an exclusive role for GV material in meiosis, mechanisms by which a lack of GV material causes meiotic defects are unknown. Knowledge of these mechanisms will help us to understand meiotic control, nuclear-cytoplasmic interactions, and cellular reprogramming. This study showed that although oocytes with prometaphase I chromosomes replaced with primary spermatocyte nuclei (PSN) did not, oocytes with GV replaced with PSN (PSG oocytes) did display meiotic defects. Among the defects, insufficient chromosome condensation with chromosome bridges was associated with spindle abnormalities. Abnormal spindle migration, cortical nonpolarization, and the aberrant spindle caused randomly positioning of cleavage furrows, leading to large first polar bodies (PB1) and unequal allocation of chromosomes and mitogen-activated protein kinases (MAPK) between oocyte and PB1. Spindle assembly checkpoint was activated but did not stop the incorrect division. The unequal MAPK allocation resulted in differences in pronuclear formation and PB1 degeneration; oocytes receiving more MAPK were more capable of forming pronuclear rudiments, whereas PB1 receiving more MAPK degenerated sooner than those that received less. Because none of the PSG oocytes or the enucleated GV oocytes injected with sperm heads showed cortical polarization in spite of chromosome localization close to the oolemma and because the PSG oocytes receiving more MAPK could form only pronuclear rudiments and not normal pronuclei, we suggest that the GV material plays essential roles in polarization and pronuclear formation on top of those played by chromosomes or MAPK. In conclusion, using PSG oocytes as models, this study has revealed the primary pathways by which a lack of GV material cause meiotic defects, laying a foundation for future research on the role of GV material in oocyte meiotic control.

  7. Abnormal rate of intraoperative and postoperative implant positioning outliers using "MRI-based patient-specific" compared to "computer assisted" instrumentation in total knee replacement.

    Science.gov (United States)

    Ollivier, M; Tribot-Laspiere, Q; Amzallag, J; Boisrenoult, P; Pujol, N; Beaufils, P

    2016-11-01

    The aim of this study was to analyze first intraoperative alignment and reason to abandon the use of patient-specific instrumentation using intraoperative CAS measurement, secondly assess by postoperative CT analysis if CI, based on preoperative 3D-MRI data, improved postoperative component positioning (including femoral rotation) and lower limb alignment as compared with results obtained with CAS. In this randomized controlled trial, 80 consecutive patients scheduled to undergo TKA were enrolled. Eligible knees were randomized to the group of PSI-TKAs (n = 40) or to the group of CAS-TKAs (n = 40). In the CAS group, CAS determined and controlled cutting block positioning in each plane. In the PSI group, CAS allowed to measure adequacy of intraoperative alignment including femoral component rotation. At 3 months after surgery, implants position were measured and analyzed with full-weight bearing plain radiographs and CT scan. Intraoperatively, there was a significant difference concerning Sagittal Femoral mechanical, Frontal tibial mechanical angle and tibial slope between the two groups (respectively p = 0.01, p = 0.02, p = 0.046). Custom instrumentation was abandoned intraoperatively in seven knees (17.5 %). Abnormal tibial cuts were responsible of the abandon in three out of seven cases, femoral cut in 1/7 and dual abnormalities in 3/7. Postoperatively, tibial slope outliers percentage was higher in the patient specific instrumentation group with six patients (18.18 %) versus one patient (2.5 %) in the CAS group (p = 0.041). Patient specific instrumentation was associated with an important number of hazardous cut and a higher rate of outliers in our series and thus should be used with caution as related to. This study is the first to our acknowledgement to compare intra-operative ancillary and implant positioning of PSI-TKA and CAS-TKA. High rate of malposition are sustained by our findings, as such PSI-TKA should be used with caution, by surgeons

  8. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  9. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA as partial replacement of cement in presence of copolymer latexes. Portland cement (PC was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA and 2-hydroxymethylacrylate (2-HEMA. Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM. The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  10. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...... of improving the fixation of implants. Of these, hydroxyapatite (HA) is the most widely used and most extensively investigated. HA is highly osseoconductive, and the positive effect is well documented in both basic and long-term clinical research [1–6]. This chapter describes experimental and clinical studies...... evaluating bone-implant fixation with HA coatings....

  11. Substituição dos ligamentos cruzados cranial e caudal em cães por duplo implante de polipropileno Replacement of the cranial and caudal cruciate ligaments in dogs by double t polypropylene implant

    Directory of Open Access Journals (Sweden)

    Daniel Curvello de Mendonça Müller

    2011-03-01

    Full Text Available O objetivo deste trabalho é salientar uma alternativa eficaz no tratamento da ruptura dos ligamentos cruzados cranial e caudal de cães, sem associação de imobilização externa. Foram atendidos seis animais portadores de ruptura de ambos os ligamentos cruzados. Optou-se pela correção cirúrgica intracapsular, utilizando-se dois implantes sintéticos de polipropileno, para a estabilização da articulação. Os pacientes retornaram ao apoio completo do membro em 11,8±3,5 dias e não mantiveram instabilidade articular, após 0, 30 e 90 dias de avaliação clínica pós-operatória. Aos 90 dias após a cirurgia, não se percebeu claudicação nos pacientes avaliados. Concluiu-se que a técnica utilizada promoveu total estabilidade articular na ausência dos ligamentos cruzados cranial e caudal.The objective of this study is to point out an effective alternative in the treatment of the cranial and caudal cruciate ligaments rupture in dogs, with no association of external immobilization. Six dogs with rupture of both cruciate ligaments were included in the present study. Stifle joint was surgically stabilized by an intracapsular technique, using two polypropylene synthetic implants. The animals returned to full member support in 11.8±3.5 days and did not sustain any joint instability degree after 0, 30 and 90 days of clinical evaluation after surgery. At 90 days after surgery, it became apparent lameness in any of the six patients. It was concluded that the technique employed caused total joint stability in the absence of caudal and cranial cruciate ligaments.

  12. The effect of perfusion culture on proliferation and differentiation of human mesenchymal stem cells on biocorrodible bone replacement material

    Energy Technology Data Exchange (ETDEWEB)

    Farack, J., E-mail: jana.farack@tu-dresden.de [Technische Universitaet Dresden, Max Bergmann Center of Biomaterials, Budapester Str. 27, D-01069 Dresden (Germany); Wolf-Brandstetter, C. [Technische Universitaet Dresden, Max Bergmann Center of Biomaterials, Budapester Str. 27, D-01069 Dresden (Germany); Glorius, S.; Nies, B. [InnoTERE GmbH, Tatzberg 47-49, D-01307 Dresden (Germany); Standke, G. [Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), Winterbergstr. 28, D-01277 Dresden (Germany); Quadbeck, P. [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Winterbergstr. 28, D-01277 Dresden (Germany); Worch, H.; Scharnweber, D. [Technische Universitaet Dresden, Max Bergmann Center of Biomaterials, Budapester Str. 27, D-01069 Dresden (Germany)

    2011-12-15

    Biocorrodible iron foams were coated with different calcium phosphate phases (CPP) to obtain a bioactive surface and controlled degradation. Further adhesion, proliferation and differentiation of SaOs-2 and human mesenchymal stem cells were investigated under both static and dynamic culture conditions. Hydroxyapatite (HA; [Ca{sub 10}(PO{sub 4}){sub 6}OH{sub 2}]) coated foams released 500 {mu}g/g iron per day for Dulbecco's modified eagle medium (DMEM) and 250 {mu}g/g iron per day for McCoys, the unmodified reference 1000 {mu}g/g iron per day for DMEM and 500 {mu}g/g iron per day for McCoys, while no corrosion could be detected on brushite (CaHPO{sub 4}) coated foams. Using a perfusion culture system with conditions closer to the in vivo situation, cells proliferated and differentiated on iron foams coated with either brushite or HA while in static cell culture cells could proliferate only on Fe-brushite. We conclude that the degradation behaviour of biocorrodible iron foams can be varied by different calcium phosphate coatings, offering opportunities for design of novel bone implants. Further studies will focus on the influence of different modifications of iron foams on the expression of oxidative stress enzymes. Additional information about in vivo reactions and remodelling behaviour are expected from testing in implantation studies.

  13. 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 ...

  14. Characterisation of Ion Implantation-induced Defects in Certain Technologically Important Materials by Positron Annihilation (Review Paper

    Directory of Open Access Journals (Sweden)

    P.M.G. Nambissan

    2009-07-01

    Full Text Available The application of positron annihilation spectroscopy for the studies of defects produced by different types of charged particles and ions in a variety of materials is discussed with specific examples. The ability to detect and quantify the information through the characteristic parameters of the annihilation radiation in a totally non-destructive method has made the fundamental process of electron-positron annihilation a powerful spectroscopic probe for investigating the structure and properties of materials. Ion implantation produces defects in the structure of solids and the latter can be recovered from the defects by annealing at high temperatures. Here the annealing is done in sequential steps so that the different stages of evolution of defects and their interaction with impurity atoms can be studied systematically. Defects produced by irradiation by particles like protons, alpha, boron and neon ions in materials ranging from simple metals to binary alloys are discussed.A detailed evaluation of the positron lifetimes in terms of the popular positron trapping models is also presented. Further as a special case, the method of extraction of values of several useful physical parameters of inert gas bubbles inside a metal matrix is explained with the help of a model analysis.Defence Science Journal, 2009, 59(4, pp.329-341, DOI:http://dx.doi.org/10.14429/dsj.59.1531

  15. An introduction to single implant abutments.

    LENUS (Irish Health Repository)

    Warreth, Abdulhadi

    2013-01-01

    This article is an introduction to single implant abutments and aims to provide basic information about abutments which are essential for all dental personnel who are involved in dental implantology. Clinical Relevance: This article provides a basic knowledge of implants and implant abutments which are of paramount importance, as replacement of missing teeth with oral implants has become a well-established clinical procedure.

  16. Patients with Intolerance Reactions to Total Knee Replacement: Combined Assessment of Allergy Diagnostics, Periprosthetic Histology, and Peri-implant Cytokine Expression Pattern

    Directory of Open Access Journals (Sweden)

    Peter Thomas

    2015-01-01

    Full Text Available We performed a combined approach to identify suspected allergy to knee arthroplasty (TKR: patch test (PT, lymphocyte transformation test (LTT, histopathology (overall grading; T- and B-lymphocytes, macrophages, and neutrophils, and semiquantitative Real-time-PCR-based periprosthetic inflammatory mediator analysis (IFNγ, TNFα, IL1-β, IL-2, IL-6, IL-8, IL-10, IL17, and TGFβ. We analyzed 25 TKR patients with yet unexplained complications like pain, effusion, and reduced range of motion. They consisted of 20 patients with proven metal sensitization (11 with PT reactions; 9 with only LTT reactivity. Control specimens were from 5 complicated TKR patients without metal sensitization, 12 OA patients before arthroplasty, and 8 PT patients without arthroplasty. Lymphocytic infiltrates were seen and fibrotic (Type IV membrane tissue response was most frequent in the metal sensitive patients, for example, in 81% of the PT positive patients. The latter also had marked periprosthetic IFNγ expression. 8/9 patients with revision surgery using Ti-coated/oxinium based implants reported symptom relief. Our findings demonstrate that combining allergy diagnostics with histopathology and periprosthetic cytokine assessment could allow us to design better diagnostic strategies.

  17. Wear-reducing Surface Functionalization of Implant Materials Using Ultrashort Laser Pulses

    Science.gov (United States)

    Oldorf, P.; Peters, R.; Reichel, S.; Schulz, A.-P.; Wendlandt, R.

    The aim of the project called "EndoLas" is the development of a reproducible and reliable method for a functionalization of articulating surfaces on hip joint endoprostheses due to a reduction of abrasion and wear by the generation of micro structures using ultrashort laser pulses. On the one hand, the microstructures shall ensure the capture of abraded particles, which cause third-body wear and thereby increase aseptic loosening. On the other hand, the structures shall improve or maintain the tribologically important lubricating film. Thereby, the cavities serve as a reservoir for the body's own synovial fluid. The dry friction, which promotes abrasion and is a part of the mixed friction in the joint, shall therefore be reduced. In experimental setups it was shown, that the abrasive wear can be reduced significantly due to micro-structuring the articulating implant surfaces. To shape the fine and deterministic cavities on the surfaces, an ultra-short pulsed laser, which is integrated in a high-precision, 5-axes micro-machining system, was used. The laser system, based on an Yb:YAG thin-disk regenerative amplifier, has an average output power of 50 W at the fundamental wavelength of 1030 nm, a maximum repetition rate of 400 kHz and a pulse duration of 6 ps. Due to this, a maximum pulse energy of 125 μJ is achievable. Furthermore external second and third harmonic generation enables the usage of wavelengths in the green and violet spectral range.

  18. A Histologic Evaluation on Tissue Reaction to Three Implanted Materials (MTA, Root MTA and Portland Cement Type I in the Mandible of Cats

    Directory of Open Access Journals (Sweden)

    F. Sasani

    2004-09-01

    Full Text Available Statement of Problem: Nowadays Mineral Trioxide aggregate (MTA is widely used for root end fillings, pulp capping, perforation repair and other endodontic treatments.Investigations have shown similar physical and chemical properties for Portland cement and Root MTA with those described for MTA.Purpose: The aim of this in vitro study was to evaluate the tissue reaction to implanted MTA, Portland cement and Root MTA in the mandible of cats.Materials and Methods: Under asepsis condition and general anesthesia, a mucoperiosteal flap, following the application of local anesthesia, was elevated to expose mandibular symphysis. Two small holes in both sides of mandible were drilled. MTA, Portland cement and Root MTA were mixed according to the manufacturers, recommendation and placed in bony cavities. In positive control group, the test material was Zinc oxide powder plus tricresoformalin. In negative control group, the bony cavities were left untreated. After 3,6 and 12 weeks, the animals were sacrificed and the mandibular sections were prepared for histologic examination under light microscope. The presence and thickness of inflammation, presence of fibrosis capsule, the severity of fibrosis and bone formation were investigated. The data were submitted to Exact Fisher test, chi square test and Kruskal-Wallis test for statistical analysis.Results: No statistically significant differences were found in the degree of inflammation,presence of fibrotic capsule, severity of fibrosis and inflammation thickness between Root MTA, Portland cement and MTA (P>0.05. There was no statistical difference in boneformation between MTA and Portland cement (P>0.05. However, bone formation was not found in any of the Root MTA specimens and the observed tissue was exclusively of fibrosis type.Conclusion: The physical and histological results observed with MTA are similar to those of Root MTA and Portland cement. Additionally, all of these three materials are biocompatible

  19. [Study of regeneration in periodontal tissue after implantation of bone ceramic and collagen gel compound materials. Evaluation of histopathological finding and autoradiography].

    Science.gov (United States)

    Miyamoto, Y; Hayashi, H; Kamoi, K

    1989-12-01

    The aim of this study is to determine the process of periodontal tissue regeneration and the metabolic activity of osteoblasts after implantation of bone ceramic and collagen gel compound materials (BC). Bone defects were artificially prepared in the alveolar septa of the bilateral upper first and second molars of Wistar rats. Subsequently, BC were implanted into the defective sites on the left side, and the gingival flaps were closed. At the defective sites on the right side, as a control, gingival flaps were closed without implantation. Rats were sacrificed 1, 3, 5, 7 or 14 weeks after implantation, and prepared tissue sections were observed both pathologically and autoradiographically using 3H-Proline. The results obtained were as follows: Pathological Findings One week after BC implantation, inflammatory cellular infiltration of the surrounding gingival connective tissue was relatively mild. Three weeks after implantation, BC were present in fibrous connective tissues, and some directly bound to the marices of regenerated bone. Observation 5 weeks after implantation revealed that BC had become embedded in the regenerated bone matrices and that there was giant cell reaction to foreign bodies at the margin of BC located in connective tissue. BC were directly bound to the regenerated bone matrices without intermediary fibrous tissues 7 and 14 weeks after implantation. Connective tissues showed high grade regeneration of collagen fiber bundles, in an arrangement that tended to be fixed in mesial and distal directions. Autoradiographic Findings There was no uptake of 3H-Proline into the regenerated bone matrices or the gingival connective tissue surrounding BC, while uptake of 3H-Proline into the entire area around the root apex and in the vicinity of the alveolar septum was observed with time (weeks) after BC implantation. These results suggest that BC provide nuclei for bone regeneration through inclusion in newly-generated periodontal bone tissue, although it is

  20. Adhesion of Streptococcus sanguinis to dental implant and restorative materials in vitro.

    Science.gov (United States)

    Hauser-Gerspach, Irmgard; Kulik, Eva M; Weiger, Roland; Decker, Eva-Maria; Von Ohle, Christiane; Meyer, Jürg

    2007-05-01

    Bacterial adhesion to tooth surfaces or dental materials starts immediately upon exposure to the oral environment. The aim of this study, therefore, was to compare the adhesion of Streptococcus sanguinis to saliva-coated human enamel and dental materials - during a one-hour period - using an in vitro flow chamber system which mimicked the oral cavity. After fluorescent staining, the number of adhered cells and their vitality were recorded. The dental materials used were: titanium (Rematitan M), gold (Neocast 3), ceramic (Vita Omega 900), and composite (Tetric Ceram). The number of adherent bacterial cells was higher on titanium, gold, and ceramic surfaces and lower on composite as compared to enamel. As for the percentage of adherent vital cells, it was higher on enamel than on the restorative materials tested. These results suggested that variations in the number and vitality of the adherent pioneer oral bacteria, S. sanguinis, in the in vitro system depended on the surface characteristics of the substratum and the acquired salivary pellicle. The in vitro adhesion model used herein provided a simple and reproducible approach to investigate the impact of surface-modified dental materials on bacterial adhesion and vitality.

  1. Review of Mechanical Testing and Modelling of Thrombus Material for Vascular Implant and Device Design.

    Science.gov (United States)

    Johnson, S; Duffy, S; Gunning, G; Gilvarry, M; McGarry, J P; McHugh, P E

    2017-08-28

    A thrombus or blood clot is a solid mass, made up of a network of fibrin, platelets and other blood components. Blood clots can form through various pathways, for example as a result of exposed tissue factor from vascular injury, as a result of low flow/stasis, or in very high shear flow conditions. Embolization of cardiac or vascular originating blood clots, causing an occlusion of the neurovasculature, is the major cause of stroke and accounts for 85% of all stroke. With mechanical thrombectomy emerging as the new standard of care in the treatment of acute ischemic stroke (AIS), the need to generate a better understanding of the biomechanical properties and material behaviour of thrombus material has never been greater, as it could have many potential benefits for the analysis and performance of these treatment devices. Defining the material properties of a thrombus has obvious implications for the development of these treatment devices. However, to-date this definition has not been adequately established. While some experimentation has been performed, model development has been extremely limited. This paper reviews the previous literature on mechanical testing of thrombus material. It also explores the use of various constitutive and computational models to model thrombus formation and material behaviour.

  2. Cytocompatibility of pure metals and experimental binary titanium alloys for implant materials.

    Science.gov (United States)

    Park, Yeong-Joon; Song, Yo-Han; An, Ji-Hae; Song, Ho-Jun; Anusavice, Kenneth J

    2013-12-01

    This study was performed to evaluate the biocompatibility of nine types of pure metal ingots (Ag, Al, Cr, Cu, Mn, Mo, Nb, V, Zr) and 36 experimental titanium (Ti) alloys containing 5, 10, 15, and 20 wt% of each alloying element. The cell viabilities for each test group were compared with that of CP-Ti using the WST-1 test and agar overlay test. The ranking of pure metal cytotoxicity from most potent to least potent was as follows: Cu>Al>Ag>V>Mn>Cr>Zr>Nb>Mo>CP-Ti. The mean cell viabilities for pure Cu, Al, Ag, V, and Mn were 21.6%, 25.3%, 31.7%, 31.7%, and 32.7%, respectively, which were significantly lower than that for the control group (p<0.05). The mean cell viabilities for pure Zr and Cr were 74.1% and 60.6%, respectively (p<0.05). Pure Mo and Nb demonstrated good biocompatibility with mean cell viabilities of 93.3% and 93.0%, respectively. The mean cell viabilities for all the Ti-based alloy groups were higher than 80% except for Ti-20 Nb (79.6%) and Ti-10 V (66.9%). The Ti-10 Nb alloy exhibited the highest cell viability (124.8%), which was higher than that of CP-Ti. Based on agar overlay test, pure Ag, Cr, Cu, Mn, and V were ranked as 'moderately cytotoxic', whereas the rest of the tested pure metals and all Ti alloys, except Ti-10 V (mild cytotoxicity), were ranked as 'noncytotoxic'. The results obtained in this study can serve as a guide for the development of new Ti-based alloy implant systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Influence of bioactive material coating of Ti dental implant surfaces on early healing and osseointegration of bone

    Energy Technology Data Exchange (ETDEWEB)

    Yeo, In-Sung [Seoul National University, Seoul (Korea, Republic of); Min, Seung-Ki [Seoul National University Dental Hospital, Seoul (Korea, Republic of); An, Young-Bai [Osstem Implant Co., Ltd., Busan (Korea, Republic of)

    2010-12-15

    The dental implant surface type is one of many factors that determine the long-term clinical success of implant restoration. The implant surface consists of bioinert titanium oxide, but recently coatings with bioactive calcium phosphate ceramics have often been used on Ti implant surfaces. Bio-active surfaces are known to significantly improve the healing time of the human bone around the inserted dental implant. In this study, we characterized two types of coated implant surfaces by scanning electron microscopy, energy dispersive spectrometry, and surface roughness testing. The effect of surface modification on early bone healing was then tested by using the rabbit tibia model to measure bone-to-implant contact ratios and removal torque values. These modified surfaces showed different characteristics in terms of surface topography, chemical composition, and surface roughness. However, no significant differences were found in the bone-to-implant contact and the resistance to removal torque between these surfaces. Both the coated implants may induce similar favorable early bone responses in terms of the early functioning and healing of dental implants even though they differed in their surface characteristics.

  4. Fly and bottom ashes from biomass combustion as cement replacing components in mortars production: rheological behaviour of the pastes and materials compression strength.

    Science.gov (United States)

    Maschio, Stefano; Tonello, Gabriele; Piani, Luciano; Furlani, Erika

    2011-10-01

    In the present research mortar pastes obtained by replacing a commercial cement with the equivalent mass of 5, 10, 20 and 30 wt.% of fly ash or bottom ash from fir chips combustion, were prepared and rheologically characterized. It was observed that the presence of ash modifies their rheological behaviour with respect to the reference blend due to the presence, in the ashes, of KCl and K2SO4 which cause precipitation of gypsum and portlandite during the first hydration stages of the pastes. Hydrated materials containing 5 wt.% of ash display compression strength and absorption at 28 d of same magnitude as the reference composition; conversely, progressive increase of ash cause a continuous decline of materials performances. Conversely, samples tested after 180 d display a marked decline of compression strength, as a consequence of potassium elution and consequent alkali-silica reaction against materials under curing.

  5. Evaluation of accuracy of complete-arch multiple-unit abutment-level dental implant impressions using different impression and splinting materials.

    Science.gov (United States)

    Buzayan, Muaiyed; Baig, Mirza Rustum; Yunus, Norsiah

    2013-01-01

    This in vitro study evaluated the accuracy of multiple-unit dental implant casts obtained from splinted or nonsplinted direct impression techniques using various splinting materials by comparing the casts to the reference models. The effect of two different impression materials on the accuracy of the implant casts was also evaluated for abutment-level impressions. A reference model with six internal-connection implant replicas placed in the completely edentulous mandibular arch and connected to multi-base abutments was fabricated from heat-curing acrylic resin. Forty impressions of the reference model were made, 20 each with polyether (PE) and polyvinylsiloxane (PVS) impression materials using the open tray technique. The PE and PVS groups were further subdivided into four subgroups of five each on the bases of splinting type: no splinting, bite registration PE, bite registration addition silicone, or autopolymerizing acrylic resin. The positional accuracy of the implant replica heads was measured on the poured casts using a coordinate measuring machine to assess linear differences in interimplant distances in all three axes. The collected data (linear and three-dimensional [3D] displacement values) were compared with the measurements calculated on the reference resin model and analyzed with nonparametric tests (Kruskal-Wallis and Mann-Whitney). No significant differences were found between the various splinting groups for both PE and PVS impression materials in terms of linear and 3D distortions. However, small but significant differences were found between the two impression materials (PVS, 91 μm; PE, 103 μm) in terms of 3D discrepancies, irrespective of the splinting technique employed. Casts obtained from both impression materials exhibited differences from the reference model. The impression material influenced impression inaccuracy more than the splinting material for multiple-unit abutment-level impressions.

  6. Materials testing facilities and programmes for fission and ion implantation damage

    Science.gov (United States)

    González de Vicente, S. M.; Boutard, J.-L.; Zinkle, S. J.; Tanigawa, H.

    2017-09-01

    Currently there is no fusion neutron dedicated source with a high enough flux to mimic irradiation conditions relevant to those to be experienced by the First Wall in a fusion reactor. Nevertheless, very valuable information can be obtained from existing irradiation sources, in particular Materials Test Reactors, Fast neutron reactors and Ion accelerators. Partial information is provided by these irradiation facilities that can be used to down select main materials candidates for DEMO fusion reactors and evaluate their performance under limited conditions. Modelling is an indispensable tool to interpret all the available information and build a test matrix of experiments to be carried out in a dedicated fusion neutron source. Available tools for testing materials exposed to ion or neutron irradiation, including their advantages and limitations when mimicking fusion conditions, are discussed in this paper. Next generation of fusion devices, such as DEMO, will need the input provided by a dedicated fusion neutron source to enable them to proceed in an efficient and safe manner to reach their full mission and performance.

  7. Biocompatibility improvement of titanium implants by coating with hybrid materials synthesized by sol-gel technique.

    Science.gov (United States)

    Catauro, M; Bollino, F; Papale, F

    2014-12-01

    Organic-inorganic hybrid materials based on zirconia and polyethylene glycol (PEG) have been synthesized via sol-gel method in the present study. Those materials, still in the sol phase, have been used to coat a titanium grade 4 (Ti-4) substrate to improve its biological properties. Dip-coating technique has been used to obtain thin films. PEG, a biocompatible polymer, used as the organic phase, has been incorporated with different percentages in an inorganic zirconium-based matrix. Those hybrids have been characterized by Fourier transform infrared spectroscopy (FTIR) to detect interactions between the two phases. The films have been examined using SEM to detect morphological changes with PEG percentages. The potential applications of the hybrid coatings in biomedical field have been evaluated by bioactivity and cytotoxicity tests. The coated titanium was immersed in simulated body fluid (SBF) for 21 days and the hydroxyapatite deposition on its surface was subsequently evaluated, as that feature can be used as an index of bone-bonding capability. SEM equipped with energy dispersive spectrometer (EDS) was used to examine hydroxyapatite formation. NIH 3T3 mouse embryonic fibroblast cells were seeded on specimens to evaluate cells-materials interactions and cell vitality was inspected using WST-8 Assay.

  8. Immediate implants in extraction sockets with periapical lesions: an illustrated review

    Directory of Open Access Journals (Sweden)

    Arthur B. Novaes Jr.

    2013-10-01

    Full Text Available Aim Immediate implantation has gained great attention since first proposed. Immediate implants in replacement of teeth with periapical lesion is, to date, an issue of discussion. The aim of this study is to perform an illustrated literature review of immediate implants in sockets exhibiting previous periapical lesions.Materials and methods A search on medline/EMBASE database was done for the literature review which is presented together with two case reports illustrating the state of the art of immediate implants on sockets with periapical lesions. Both cases are presented in areas with great aesthetic demands and a periapical lesion of considerable size. The two cases were conducted following strict granulation tissue removal and careful rinsing and pre-operative antibiotics, followed by good primary stability of the dental implant.Results and conclusion Both cases represented successes in aesthetics and function, describing a successful protocol for immediate implant installation in areas exhibiting periapical lesions.

  9. Monitoring the Changes of Material Properties at Bone-Implant Interface during the Healing Process In Vivo: A Viscoelastic Investigation

    Science.gov (United States)

    Chen, Hsiang-Ho; Lai, Wei-Yi; Chee, Tze-Jian

    2017-01-01

    The aim of this study was to monitor the changes of viscoelastic properties at bone-implant interface via resonance frequency analysis (RFA) and the Periotest device during the healing process in an experimental rabbit model. Twenty-four dental implants were inserted into the femoral condyles of rabbits. The animals were sacrificed immediately after implant installation or on day 14, 28, or 56 after surgery. Viscoelastic properties at bone-implant interface were evaluated by measuring the implant stability quotient (ISQ) using RFA and by measuring the Periotest values (PTVs) using the Periotest device. The bone/implant specimens were evaluated histopathologically and histomorphometrically to determine the degree of osseointegration (BIC%). The BIC% values at different time points were then compared with the corresponding ISQ values and PTVs. The mean ISQ value increased gradually and reached 81 ± 1.7 on day 56, whereas the mean PTV decreased over time, finally reaching −0.7 ± 0.5 on day 56. Significant correlations were found between ISQ and BIC% (r = 0.701, p < 0.001), PTV and BIC% (r = −0.637, p < 0.05), and ISQ and PTV (r = −0.68, p < 0.05). These results show that there is a positive correlation between implant stability parameters and peri-implant-bone healing, indicating that the RFA and Periotest are useful for measuring changes of viscoelastic properties at bone-implant interface and are reliable for indirectly predicting the degree of osseointegration. PMID:28373978

  10. Passive and active middle ear implants

    Directory of Open Access Journals (Sweden)

    Beutner, Dirk

    2009-01-01

    Full Text Available Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants.

  11. Parasitic reactions and the balance of materials in lithium batteries for implantable medical devices

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, A.M. (Medtronic, Inc., Minneapolis, MN (United States)); Skarstad, P.M. (Medtronic, Inc., Minneapolis, MN (United States))

    1993-03-15

    The parasitic reactions that occur in lithium/silver vanadium oxide cells have been investigated by microcalorimetry. Reactions between lithium and components of the electrolyte are the biggest contributors to heat output. The rate of parasitic reaction of lithium needs to be known to ensure that the batteries are not anode-limited. This parameter is one of many included in a calculation of the balance of materials in the cell. This calculation ensures the proper balance of electrodes and electrolyte solution in a constrained volume and also determines electrode dimensions. (orig.)

  12. Directed Replacement

    CERN Document Server

    Karttunen, L

    1996-01-01

    This paper introduces to the finite-state calculus a family of directed replace operators. In contrast to the simple replace expression, UPPER -> LOWER, defined in Karttunen (ACL-95), the new directed version, UPPER @-> LOWER, yields an unambiguous transducer if the lower language consists of a single string. It transduces the input string from left to right, making only the longest possible replacement at each point. A new type of replacement expression, UPPER @-> PREFIX ... SUFFIX, yields a transducer that inserts text around strings that are instances of UPPER. The symbol ... denotes the matching part of the input which itself remains unchanged. PREFIX and SUFFIX are regular expressions describing the insertions. Expressions of the type UPPER @-> PREFIX ... SUFFIX may be used to compose a deterministic parser for a ``local grammar'' in the sense of Gross (1989). Other useful applications of directed replacement include tokenization and filtering of text streams.

  13. Three-dimensional printing of drug-eluting implants: preparation of an antimicrobial polylactide feedstock material.

    Science.gov (United States)

    Water, Jorrit Jeroen; Bohr, Adam; Boetker, Johan; Aho, Johanna; Sandler, Niklas; Nielsen, Hanne Mørck; Rantanen, Jukka

    2015-03-01

    The aim of the present work was to investigate the potential of three-dimensional (3D) printing as a manufacturing method for products intended for personalized treatments by exploring the production of novel polylactide-based feedstock materials for 3D printing purposes. Nitrofurantoin (NF) and hydroxyapatite (HA) were successfully mixed and extruded with up to 30% drug load with and without addition of 5% HA in polylactide strands, which were subsequently 3D-printed into model disc geometries (10 × 2 mm). X-ray powder diffraction analysis showed that NF maintained its anhydrate solid form during the processing. Release of NF from the disks was dependent on the drug loading in a concentration-dependent manner as a higher level of released drug was observed from disks with higher drug loads. Disks with 30% drug loading were able to prevent surface-associated and planktonic growth of Staphylococcus aureus over a period of 7 days. At 10% drug loading, the disks did not inhibit planktonic growth, but still inhibited surface-associated growth. Elemental analysis indicated the presence of microdomains of solid drug supporting the observed slow and partial drug release. This work demonstrates the potential of custom-made, drug-loaded feedstock materials for 3D printing of pharmaceutical products for controlled release. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. Clinical management and microscopic characterisation of fatique-induced failure of a dental implant. Case report

    Directory of Open Access Journals (Sweden)

    De Frenza G

    2006-06-01

    Full Text Available Abstract Background Osseointegrated endosseous implants are widely used for the rehabilitation of completely and partially edentulous patients, being the final prosthodontic treatment more predictable and the failures extremely infrequent. A case of fracture of an endosseous dental implant, replacing the maxillary first molar, occurring in a middle-age woman, 5 years after placement is reported. Materials and methods The difficult management of this rare complication of implant dentistry together with the following rehabilitation is described. Additionally, the authors performed an accurate analysis of the removed fractured implant both by the stereomicroscope and by the confocal laser scanning microscope. Results and discussion The fractured impant showed the typical signs of a fatigue-induced fracture in the coronal portion of the implant together with numerous micro-fractures in the apical one. Three dimensional imaging performed by confocal laser scanning microscope led easily to a diagnosis of "fatigue fracture" of the implant. The biomechanical mechanism of implant fractures when overstress of the implant components due to bending overload is discussed. Conclusion When a fatigue-induced fracture of an dental implant occurs in presence of bending overload, the whole implant suffers a deformation that is confirmed by the alterations (micro-fractures of the implant observable also in the osseointegrated portion that is easily appraisable by the use of stereomicroscope and confocal laser scanning microscope without preparation of the sample.

  15. Resultados de artroplastia total de joelho com e sem implante de recapeamento (resurfacing patelar Results of total knee replacement with/without resurfacing of the patella

    Directory of Open Access Journals (Sweden)

    Abdul Khan

    2012-01-01

    Full Text Available OBJETIVO: Estudar a diferença de dor, estalido e crepitação patelofemoral no pós-operatório em pacientes com ou sem recapeamento patelar após 5 anos, os quais tinham dor patelofemoral antes da cirurgia. Estudar a incidência de dor, estalido e crepitação patelofemoral depois de pateloplastia em ambos os grupos. MÉTODOS: Revisão retrospectiva de 765 pacientes submetidos a artroplastia total do joelho (ATJ com ou sem recapeamento patelar. Os pacientes foram perguntados sobre dor pré e pós-operatória, 5 anos depois da cirurgia. Foram examinados por enfermeiro especializado 5 anos, após a cirurgia para verificar estalidos ou crepitação patelofemoral (PF. RESULTADOS: 688 pacientes (89,9% tinham dor PF pré-operatória. De 688 pacientes, 449 tinham recapeamento patelar (R e 239 não tinham (NR. Trinta e seis pacientes do grupo NR tinham pateloplastia. A incidência de dor PF pós-operatória foi 13,3% no grupo R e 13,6% no grupo NR. A incidência de estalido PF pós-operatório no grupo R foi 10,4% e apenas 1,3% no grupo NR (estatisticamente significante, p OBJECTIVE: To study the difference of post-op patellofemoral pain, clunk and crepitus in patients with/without resurfacing at 5 years who had pre-op patellofemoral pain. To study the incidence of post-operative patellofemoral pain, clunk and crepitus following patelloplasty in both the groups. METHODS: Retrospective review of 765 patients who had total knee replacement with/without resurfacing.Patients were asked about both pre-operative pain and also post-operative pain 5 years after the operation. Patients were examined by a specialist nurse at 5 years post-operatively to check for any patellofemoral clunk/crepitus. RESULTS: 688 patients (89.9% had preoperative PF pain. Of 688 patients, 449 had patellar resurfacing and 239 had not (NR. Thirty-six patients from the NR group had patelloplasty. The incidence of postoperative PF pain was 13.3% in the R group and 13.6% in the NR group

  16. Complications in implant dentistry

    Science.gov (United States)

    Hanif, Ayesha; Qureshi, Saima; Sheikh, Zeeshan; Rashid, Haroon

    2017-01-01

    After tooth loss, an individual may seek tooth replacement so that his/her function and esthetics could be restored. Clinical prosthodontics, during the past decade, has significantly improved and developed according to the advancements in the science and patient's demands and needs. Conventional options in prosthodontics for substituting a missing single tooth include the removable partial denture, partial and full coverage bridgework, and resin-bonded bridgework. Dental implants have gained increasing popularity over the years as they are capable of restoring the function to near normal in both partial and completely edentulous arches. With substantial evidence available, fixed implant-supported prosthesis are fully acknowledged as a reliable treatment option for the replacement of single or multiple missing teeth nowadays. While dental implants are increasingly becoming the choice of replacement for missing teeth, the impediments associated with them are progressively emerging too. PMID:28435381

  17. The incorporation of wood waste ash as a partial cement replacement material for making structural grade concrete: An overview

    Directory of Open Access Journals (Sweden)

    Swaptik Chowdhury

    2015-06-01

    Full Text Available With increasing industrialization, the industrial byproducts (wastes are being accumulated to a large extent, leading to environmental and economic concerns related to their disposal (land filling. Wood ash is the residue produced from the incineration of wood and its products (chips, saw dust, bark for power generation or other uses. Cement is an energy extensive industrial commodity and leads to the emission of a vast amount of greenhouse gases, forcing researchers to look for an alternative, such as a sustainable building practice. This paper presents an overview of the work and studies done on the incorporation of wood ash as partial replacement of cement in concrete from the year 1991 to 2012. The aspects of wood ash such as its physical, chemical, mineralogical and elemental characteristics as well as the influence of wood ash on properties such as workability, water absorption, compressive strength, flexural rigidity test, split tensile test, bulk density, chloride permeability, freeze thaw and acid resistance of concrete have been discussed in detail.

  18. Characterization of implant materials in fetal bovine serum and sodium sulfate by electrochemical impedance spectroscopy. II. Coarsely sandblasted samples.

    Science.gov (United States)

    Contu, F; Elsener, B; Böhni, H

    2003-10-01

    Electrochemical impedance spectroscopy is used to investigate the corrosion resistance of coarsely sandblasted implant alloys, commercially pure titanium, Ti6Al4V, Ti6Al7Nb, and CoCrMo in 0.1M sodium sulfate and fetal bovine serum. Coarsely sandblasted samples have a heterogeneous surface constituted by a large number of protrusions and recessions. Impedance spectra collected in sodium sulfate present two time constants (maxima in the phase-angle of the bode plot) associated with the total surface and with the tips, respectively. In bovine serum, the two maxima in the impedance spectra cannot be distinguished because of the formation of an adsorption layer of organic molecules, which causes a decrease in the values of both the total and tips' capacitances as well as an increase in the polarization resistance. Ti6Al4V and Ti6Al7Nb show the highest corrosion rate both in serum and in sodium sulfate. Based on the capacitance values obtained in sodium sulfate, the real surface area of the coarsely sandblasted electrodes has been estimated relative to mechanically polished surfaces. The values of the effective electrode area correlate with the mechanical properties of the samples: in fact, the softest electrode (commercially pure titanium) shows the largest effective electrode area, whereas the hardest material (CoCrMo alloy) shows the smallest surface area.

  19. 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 ...

  20. The role of angiogenesis in implant dentistry part II: The effect of bone-grafting and barrier membrane materials on angiogenesis

    Science.gov (United States)

    Asatourian, Armen; Garcia-Godoy, Franklin; Sheibani, Nader

    2016-01-01

    Background In implant dentistry, bone substitute materials and barrier membranes are used in different treatments including guided bone regeneration (GBR), socket preservation, alveolar ridge augmentation, maxillary sinus elevation, and filling bony defects around the inserted dental implant. One of the most important factors in prognosis of treatments using these materials is the growth of new blood vessels in applied areas. Present review was performed to evaluate the effect of the bone-grafting and barrier membrane materials on angiogenesis events. Material and Methods An electronic search was performed in PubMed, MEDLINE, and EMBASE databases via OVID using the keywords mentioned in the PubMed and MeSH headings regarding the role of angiogenesis in implant dentistry from January 2000-April 2014. Results Of the 5,622 articles identified in our initial search results, only 33 met the inclusion criteria set for this review. Among bone substitute materials the autogenous bone-grafts, and among the barrier membranes the collagenous membranes, had the highest angiogenic potentials. Other bone-grafting materials or membranes were mostly used with pro-angiogenic factors to enhance their angiogenic properties. Conclusions Angiogenesis is one of the key factors, which plays a critical role in success rate of GBR technique and is seriously considered in manufacturing bone-grafting and barrier membrane materials. However, there is still lack of clinical and in-vivo studies addressing the effect of angiogenesis in treatments using bone-grafting and barrier membrane materials. Key words:Angiogenesis, bone-grafting materials, GBR, ridge augmentation, sinus elevation, socket preservation. PMID:27031074

  1. Ion Implantation in Ge: Structural and electrical investigation of the induced lattice damage & Study of the lattice location of implanted impurities

    CERN Document Server

    Decoster, Stefan; Wahl, Ulrich

    The past two decades, germanium has drawn international attention as one of the most promising materials to replace silicon in semiconductor applications. Due to important advantages with respect to Si, such as the increased electron and hole mobility, Ge is well on its way to become an important material in future high-speed integrated circuits. Although the interest in this elemental group IV semiconductor is increasing rapidly nowadays, the number of publications about this material is still relatively scarce, especially when compared to Si. The most widely used technique to dope semiconductors is ion implantation, due to its good control of the dopant concentration and profile, and the isotopic purity of the implanted species. However, there is a major lack of knowledge of the fundamental properties of ion implantation in Ge, which has triggered the research presented in this thesis. One of the most important and generally unwanted properties of ion implantation is the creation of damage to the crystal la...

  2. The influence of various occlusal materials on stresses transferred to implant-supported prostheses and supporting bone: a three-dimensional finite-element study.

    Science.gov (United States)

    Sevimay, Mujde; Usumez, Aslihan; Eskitascioglu, Gurcan

    2005-04-01

    The aim of this numerical analysis was to evaluate the amount and localization of stress that occurs with various materials used in implant-crown design under functional forces. Computer-aided design techniques and a finite-element stress analysis method were used for evaluation. A 4.1 x 10-mm implant placed in the mandibular second premolar area was simulated and analyzed. Simulation and analysis were performed with the use of COSMOS/M software and Pro/Engineer 2000i on a Dual Pentium III 1-GHz computer. Crown designs were as follows: porcelain fused to noble metal crown, porcelain fused to base metal crown, In-Ceram porcelain crown, and IPS Empress 2 porcelain crown. A 300-N vertical force was applied to the centric relation stop points of the crowns. The results of this study indicated that different types of restorative materials play an important role in the amount and distribution of the stresses in the superstructure and the implant. The highest stress values were observed in the IPS Empress 2 porcelain crown design (600 MPa). Porcelain fused to base metal and In-Ceram framework designs transferred less stress to abutment. Type of restorative materials used in implant crown designs are significant factors in the amount and distribution of the stresses on superstructure and implant under functional forces. Porcelain fused to base metal (149 MPa) and In-Ceram (173 MPa) crown designs induced higher von Mises stress values within the framework than porcelain fused to noble metal (108 MPa) and IPS Empress 2 (119 MPa) porcelain crown designs.

  3. Comparison of a xenogeneic and an alloplastic material used in dental implants in terms of physico-chemical characteristics and in vivo inflammatory response

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Andreia [Experimental Pathology Service, University of Coimbra, 3004-504 Coimbra (Portugal); Dentistry Department, University of Coimbra, 3030-005 Coimbra (Portugal); Catholic Portuguese University, Health Sciences Department, 3504-505 Viseu (Portugal); Coimbra, Patrícia, E-mail: patricia@Eq.uc.pt [Chemical Engineering Department, University of Coimbra, 3030-290 Coimbra (Portugal); Cabrita, António [Experimental Pathology Service, University of Coimbra, 3004-504 Coimbra (Portugal); Guerra, Fernando [Dentistry Department, University of Coimbra, 3030-005 Coimbra (Portugal); Figueiredo, Margarida [Chemical Engineering Department, University of Coimbra, 3030-290 Coimbra (Portugal)

    2013-08-01

    Two commercial bone grafts used in dentistry (Osteobiol Gen-Os®, a xenograft of porcine origin, and Bonelike®, a hydroxyapatite based synthetic material), in the form of granules, were characterized and evaluated in vivo regarding the intensity of the tissue inflammatory response. These biomaterials were characterized in terms of morphology, particle size distribution, porosity and pore size, specific surface area and density. The chemical composition and structure of the materials were accessed by Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). The graft materials were implanted in the gluteus maximus muscles of Wistar rats and the inflammatory response was evaluated through histological analysis, after one week of implantation. The results showed that the two grafts have quite different characteristics in practically all the evaluated properties. While Osteobiol® exhibits a structure and composition similar to the natural bone, Bonelike® is constituted by a main crystalline phase of hydroxyapatite and two secondary phases of α- and β-tricalcium phosphate. Osteobiol® granules, besides being larger, are irregular, and exhibit sharp-edged tips, while those of Bonelike® are approximately cylindrical, with round contours, and more uniform in size. The in vivo response evaluated from the inflammatory infiltrates revealed that although both implants did not cause severe inflammation, Bonelike® granules elicit a consistently more intense inflammatory reaction than that triggered by the granules of Osteobiol®, particularly in terms of collagen production and formation of fibrous capsule. This reaction was partly explained in terms of the characteristics evaluated for the granules of this material. - Highlights: • Two commercial bone grafts – Bonelike® and Osteobio® – were characterized. • In vivo inflammatory response was evaluated after 1 week implantation. • Both materials did not cause severe inflammation.

  4. Microleakage Evaluation at Implant-Abutment Interface Using Radiotracer Technique

    Directory of Open Access Journals (Sweden)

    Hakimeh Siadat

    2016-10-01

    Full Text Available Objectives: Microbial leakage through the implant-abutment (I-A interface results in bacterial colonization in two-piece implants. The aim of this study was to compare microleakage rates in three types of Replace abutments namely Snappy, GoldAdapt, and customized ceramic using radiotracing.Materials and Methods: Three groups, one for each abutment type, of five implants and one positive and one negative control were considered (a total of 17 regular body implants. A torque of 35 N/cm was applied to the abutments. The samples were immersed in thallium 201 radioisotope solution for 24 hours to let the radiotracers leak through the I-A interface. Then, gamma photons received from the radiotracers were counted using a gamma counter device. In the next phase, cyclic fatigue loading process was applied followed by the same steps of immersion in the radioactive solution and photon counting.Results: Rate of microleakage significantly increased (P≤0.05 in all three types of abutments (i.e. Snappy, GoldAdapt, and ceramic after cyclic loading. No statistically significant differences were observed between abutment types after cyclic loading.Conclusions: Microleakage significantly increases after cyclic loading in all three Replace abutments (GoldAdapt, Snappy, ceramic. Lowest microleakage before and after cyclic loading was observed in GoldAdapt followed by Snappy and ceramic.Keywords: Dental Implants; Dental Implant-Abutment Design; Thallium Chloride

  5. Long term preservation of motion with artificial cervical disc implants: A comparison between cervical disc replacement and rigid fusion with cage

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2014-01-01

    Background: With the advancement of technologies there is more interest in the maintenance of the spine's biomechanical properties focusing on the preservation of the functional motion segment. In present article we describe our experience with 25 cases managed with artificial cervical discs with 28 Solis cage following cervical discectomy with a mean follow-up period of 7.5 year. Materials and Methods: All surgeries were performed by single surgeon from March 2004 to June 2005 with a follow-up till date. Patients with symptomatic single or multiple level diseases that had no prior cervical surgery were candidates for the study. Cohort demographics were comparable. Standardized clinical outcome measures and radiographic examinations were used at prescribed post-operative intervals to compare the treatment groups. Relief in radicular pain, cervical spine motion, and degenerative changes at follow-up were noted. Results: In a total 53 cases, the mean age in prosthesis group was 47 years (age range: 30-63 years) and mean age in cage group was 44 years (32-62 years). Mean hospital stay was 2.7 days in both the groups. At 4 weeks complete cervical movements could be achieved in 19 cases in artificial disc group. Maintenance of movement after 7.5 years was in 76% of these patients. Lordosis was maintained in all cases till date. There was no mortality or wound infection in our series. Conclusions: We conclude that artificial cervical disc could be an alternative to fixed spinal fusion as it represents the most physiological substitute of disc. However, there is need for further studies to support the use of artificial cervical disc prosthesis. PMID:25685218

  6. Knee Replacement

    Science.gov (United States)

    ... need knee replacement surgery usually have problems walking, climbing stairs, and getting in and out of chairs. Some ... a total living space on one floor since climbing stairs can be difficult. Install safety bars or a ...

  7. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European...... countries. METHODS: A multi-institutional, non-randomized, retrospective analysis was conducted among 2,932 patients who underwent AVR surgery at seven tertiary cardiac surgery centers throughout Europe. Demographic and perioperative variables including valve size and type, body surface area (BSA) and early...

  8. Replacing penalties

    Directory of Open Access Journals (Sweden)

    Vitaly Stepashin

    2017-01-01

    Full Text Available УДК 343.24The subject. The article deals with the problem of the use of "substitute" penalties.The purpose of the article is to identify criminal and legal criteria for: selecting the replacement punishment; proportionality replacement leave punishment to others (the formalization of replacement; actually increasing the punishment (worsening of legal situation of the convicted.Methodology.The author uses the method of analysis and synthesis, formal legal method.Results. Replacing the punishment more severe as a result of malicious evasion from serving accused designated penalty requires the optimization of the following areas: 1 the selection of a substitute punishment; 2 replacement of proportionality is serving a sentence other (formalization of replacement; 3 ensuring the actual toughening penalties (deterioration of the legal status of the convict. It is important that the first two requirements pro-vide savings of repression in the implementation of the replacement of one form of punishment to others.Replacement of punishment on their own do not have any specifics. However, it is necessary to compare them with the contents of the punishment, which the convict from serving maliciously evaded. First, substitute the punishment should assume a more significant range of restrictions and deprivation of certain rights of the convict. Second, the perfor-mance characteristics of order substitute the punishment should assume guarantee imple-mentation of the new measures.With regard to replacing all forms of punishment are set significant limitations in the application that, in some cases, eliminates the possibility of replacement of the sentence, from serving where there has been willful evasion, a stricter measure of state coercion. It is important in the context of the topic and the possibility of a sentence of imprisonment as a substitute punishment in cases where the original purpose of the strict measures excluded. It is noteworthy that the

  9. High Mobility, Hole Transport Materials for Highly Efficient PEDOT:PSS Replacement in Inverted Perovskite Solar Cells

    KAUST Repository

    Neophytou, Marios

    2017-04-24

    Perovskite solar cells are one of the most promising photovoltaic technologies, due to their rapid increase in power conversion efficiency (3.8% to 21.1%) in a very short period of time and the relative ease of their fabrication compared to traditional inorganic solar cells. One of the drawbacks of perovskite solar cells is their limited stability in non-inert atmospheres. In the inverted device configuration this lack of stability can be attributed to the inclusion of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) as the hole transporting layer. Herein we report the synthesis of two new triarylamine based hole transporting materials, synthesised from readily available starting materials. These new materials show increased power conversion efficiencies, of 13.0% and 12.1%, compared to PEDOT:PSS (10.9%) and exhibit increased stability achieving lifetimes in excess of 500 hours. Both molecules are solution processible at low temperatures and offer potential for low cost, scalable production on flexible substrates for large scale perovskite solar cells.

  10. 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.

  11. Replacement Of Reserves Zinc Producers In The Russian Federation Based On The Recycling Of Technogenic Raw Materials

    Directory of Open Access Journals (Sweden)

    Alexandr Ivanovich Tatarkin

    2014-12-01

    Full Text Available In the article, the key stage of the value chain in the zinc industry of the Russian Federation is considered. The study aims to examine the impact of technological change on the development of value chains in the mining and metallurgical complex in the Urals region. The relevance of the assessment of the impact of technological change on the development of value chains in the processing of primary and technogenic raw materials in terms of the Ural Mining and Metallurgical Complex is grounded. The methodological scheme of analysis of value chains and the impact on them of new technologies are developed in the study. It is shown that the analysis of value chains should be carried out, using as an analytical tool value added as well as a heuristic tool study of the value chain. Analysis of the value chain in the production of primary zinc and technogenic raw materials made in accordance with the proposed approach. An assessment of the value added in the production of zinc from primary raw materials held in the article. The gross volume and dynamics of revenue, net income and the cost of segments of the value chain in zinc production are analyzed. The leading role of the metallurgical segment in the value chain of the zinc industry is established. Share indexes of the metallurgical segment as a control link of the value chain in the structure of the consolidated revenue, profit, cost considered in the dynamics, the dynamics of change in the total expenditure on scientific and technological development and R & D expenditure are investigated. The conclusion about essential influence of new technologies on the change of value chains in terms of zinc production is confirmed.

  12. Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

    NARCIS (Netherlands)

    Raghoebar, GM; Batenburg, RHK; Vissink, A; Reintsema, H

    1996-01-01

    Purpose: This study evaluated the applicability of intraorally harvested autogenous bone grafts for the augmentation of the narrow maxillary alveolar ridge to enable insertion of implants for single tooth replacement. Materials and Methods: Local defects of the anterior maxilla were reconstructed in

  13. Stress distribution in fixed-partial prosthesis and peri-implant bone tissue with different framework materials and vertical misfit levels: a three-dimensional finite element analysis.

    Science.gov (United States)

    Bacchi, Ataís; Consani, Rafael L X; Mesquita, Marcelo F; dos Santos, Mateus B F

    2013-09-01

    The purpose of this study was to evaluate the influence of superstructure material and vertical misfits on the stresses created in an implant-supported partial prosthesis. A three-dimensional (3-D) finite element model was prepared based on common clinical data. The posterior part of a severely resorbed jaw with two osseointegrated implants at the second premolar and second molar regions was modeled using specific modeling software (SolidWorks 2010). Finite element models were created by importing the solid model into mechanical simulation software (ANSYS Workbench 11). The models were divided into groups according to the prosthesis framework material (type IV gold alloy, silver-palladium alloy, commercially pure titanium, cobalt-chromium alloy, or zirconia) and vertical misfit level (10 µm, 50 µm, and 100 µm) created at one implant-prosthesis interface. The gap of the vertical misfit was set to be closed and the stress values were measured in the framework, porcelain veneer, retention screw, and bone tissue. Stiffer materials led to higher stress concentration in the framework and increased stress values in the retention screw, while in the same circumstances, the porcelain veneer showed lower stress values, and there was no significant difference in stress in the peri-implant bone tissue. A considerable increase in stress concentration was observed in all the structures evaluated within the misfit amplification. The framework material influenced the stress concentration in the prosthetic structures and retention screw, but not that in bone tissue. All the structures were significantly influenced by the increase in the misfit levels.

  14. Sol-gel synthesis and characterization of SiO2/PEG hybrid materials containing quercetin as implants with antioxidant properties

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Gloria, Antonio

    2016-05-01

    In the present work, Silica/Polyethylene glycol (PEG) hybrid nanocomposites containing an antioxidant agent, the quercetin, were synthesized via sol-gel to be used as implants with antioxidant properties. Fourier transform infrared (FT-IR) analysis proved that a modification of both polymer and quercetin occurs due to synthesis process. Scanning electron microscope (SEM) showed that the proposed materials were hybrid nanocomposites. The bioactivity was ascertained by soaking the samples in a simulated body fluid (SBF).

  15. Sol-gel synthesis and characterization of SiO{sub 2}/PEG hybrid materials containing quercetin as implants with antioxidant properties

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, Michelina; Bollino, Flavia [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 21, 81031 Aversa (Italy); Gloria, Antonio [Institute of Polymers, Composites and Biomaterials - National Research Council of Italy, V.le J. F. Kennedy 54 - Mostra d’Oltremare Pad. 20, 80125 Naples (Italy)

    2016-05-18

    In the present work, Silica/Polyethylene glycol (PEG) hybrid nanocomposites containing an antioxidant agent, the quercetin, were synthesized via sol-gel to be used as implants with antioxidant properties. Fourier transform infrared (FT-IR) analysis proved that a modification of both polymer and quercetin occurs due to synthesis process. Scanning electron microscope (SEM) showed that the proposed materials were hybrid nanocomposites. The bioactivity was ascertained by soaking the samples in a simulated body fluid (SBF).

  16. 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...

  17. Tribological comparison of materials

    Science.gov (United States)

    Shi, Bing

    Approximately 600,000 total joint replacement surgeries are performed each year in the United States. Current artificial joint implants are mainly metal-on-plastic. The synthetic biomaterials undergo degradation through fatigue and corrosive wear from load-bearing and the aqueous ionic environment of the human body. Deposits of inorganic salts can scratch weight-bearing surfaces, making artificial joints stiff and awkward. The excessive wear debris from polyethylene leads to osteolysis and potential loosening of the prosthesis. The lifetime for well-designed artificial joints is at most 10 to 15 years. A patient can usually have two total joint replacements during her/his lifetime. Durability is limited by the body's reaction to wear debris of the artificial joints. Wear of the artificial joints should be reduced. A focus of this thesis is the tribological performance of bearing materials for Total Replacement Artificial Joints (TRAJ). An additional focus is the scaffolds for cell growth from both a tissue engineering and tribological perspective. The tribological properties of materials including Diamond-like Carbon (DLC) coated materials were tested for TRAJ implants. The DLC coatings are chemically inert, impervious to acid and saline media, and are mechanically hard. Carbon-based materials are highly biocompatible. A new alternative to total joints implantation is tissue engineering. Tissue engineering is the replacement of living tissue with tissue that is designed and constructed to meet the needs of the individual patient. Cells were cultured onto the artificial materials, including metals, ceramics, and polymers, and the frictional properties of these materials were investigated to develop a synthetic alternative to orthopedic transplants. Results showed that DLC coated materials had low friction and wear, which are desirable tribological properties for artificial joint material. Cells grew on some of the artificial matrix materials, depending on the

  18. Direct laser metal sintering as a new approach to fabrication of an isoelastic functionally graded material for manufacture of porous titanium dental implants.

    Science.gov (United States)

    Traini, T; Mangano, C; Sammons, R L; Mangano, F; Macchi, A; Piattelli, A

    2008-11-01

    This work focuses on a titanium alloy implants incorporating a gradient of porosity, from the inner core to the outer surface, obtained by laser sintering of metal powder. Surface appearance, microstructure, composition, mechanical properties and fractography were evaluated. All the specimens were prepared by a selective laser sintering procedure using a Ti-6Al-4V alloy powder with a particle size of 1-10 microm. The morphological and chemical analyses were performed by SEM and energy dispersive X-ray spectroscopy. The flexure strength was determined by a three-point bend test using a universal testing machine. The surface roughness was investigated using a confocal scanning laser microscope. The surface roughness variation was statistically evaluated by use of a Chi square test. A p value of metal core consisted of columnar beta grains with alpha and beta laths within the grains. The alloy was composed of 90.08% Ti, 5.67% Al and 4.25% V. The Young's modulus of the inner core material was 104+/-7.7 GPa; while that of the outer porous material was 77+/-3.5 GPa. The fracture face showed a dimpled appearance typical of ductile fracture. In conclusion, laser metal sintering proved to be an efficient means of construction of dental implants with a functionally graded material which is better adapted to the elastic properties of the bone. Such implants should minimize stress shielding effects and improve long-term performance.

  19. Laser and electron-beam powder-bed additive manufacturing of metallic implants: A review on processes, materials and designs.

    Science.gov (United States)

    Sing, Swee Leong; An, Jia; Yeong, Wai Yee; Wiria, Florencia Edith

    2016-03-01

    Additive manufacturing (AM), also commonly known as 3D printing, allows the direct fabrication of functional parts with complex shapes from digital models. In this review, the current progress of two AM processes suitable for metallic orthopaedic implant applications, namely selective laser melting (SLM) and electron beam melting (EBM) are presented. Several critical design factors such as the need for data acquisition for patient-specific design, design dependent porosity for osteo-inductive implants, surface topology of the implants and design for reduction of stress-shielding in implants are discussed. Additive manufactured biomaterials such as 316L stainless steel, titanium-6aluminium-4vanadium (Ti6Al4V) and cobalt-chromium (CoCr) are highlighted. Limitations and future potential of such technologies are also explored. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  20. Dental Implants: Dual Stabilization Technology

    OpenAIRE

    Saini, Rajiv

    2015-01-01

    More recent epidemiological data seem to show an increasing trend of tooth loss due to periodontal reasons rather than caries; the presence of initial attachment loss, bone height and the habit of smoking significantly increase the risk of tooth mortality. A dental implant is a titanium screw which is placed into bone to replace missing teeth. The implant mimics the root of a tooth in function. Dental Implants have changed the face of dentistry over the last three decades. Success of dental i...

  1. Morphology of hydroxyapatite coated nanotube surface of Ti-35Nb-xHf alloys for implant materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Un [Functional Coatings Group, Materials Processing Division, Korea Institute of Materials Science (KIMS), Changwon, Kyungnam (Korea, Republic of); Jeong, Yong-Hoon [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of); Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave. Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of)

    2011-11-01

    The purpose of this research is to study the morphology of hydroxyapatite coated nanotube surface of Ti-35Nb-xHf for implant materials using various experiments. For this study, Ti-35Nb-xHf (x = 0, 3, 7 and 15 wt.%) alloys were prepared by arc melting and heat treated for 12 h at 1000 Degree-Sign C in an argon atmosphere and then water quenching. Nanotube formation on the Ti-35Nb-xHf alloys was achieved by anodizing in H{sub 3}PO{sub 4} electrolytes containing 0.8 wt.% NaF at room temperature. Anodization was carried out using an electrochemical method and all experiments were conducted at room temperature. Hydroxyapatite (HA) was deposited on the nanotubular Ti-35Nb-xHf alloys surface for the biomaterials by radio-frequency (RF) magnetron sputtering method. The morphologies of nanotubular and HA coated surface were characterized by X-ray diffractometer (XRD), optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM). The wettability of HA coated surface was measured by contact angle goniometer. The microstructure of Ti-35Nb-xHf alloys was transformed needle-like to equiaxed structure with Hf content and {alpha} Double-Prime phase decreased, whereas {beta} phase increased as Hf content increased. HA coating surface was affected by microstructure of bulk and morphology of nanotube formation. In case of low Hf content, tip of nanotube formed at {beta} phase was coated with HA film, whereas {alpha} Double-Prime phase was not coated with HA film. In case of high Hf content, nanotube surface was coated uniformly with HA film. The wettability of HA coated nanotubular surface was higher than that of non coated samples.

  2. Electrochemical and morphological investigation of silver and zinc modified calcium phosphate bioceramic coatings on metallic implant materials

    Energy Technology Data Exchange (ETDEWEB)

    Furko, M., E-mail: monika.furko@bayzoltan.hu [Bay Zoltán Nonprofit Ltd. for Applied Research, H-1116 Budapest, Fehérvári u. 130 (Hungary); Jiang, Y.; Wilkins, T.A. [Institute of Particle Science and Engineering, University of Leeds, LS2 9JT (United Kingdom); Balázsi, C. [Bay Zoltán Nonprofit Ltd. for Applied Research, H-1116 Budapest, Fehérvári u. 130 (Hungary)

    2016-05-01

    In our research nanostructured silver and zinc doped calcium-phosphate (CaP) bioceramic coatings were prepared on commonly used orthopaedic implant materials (Ti6Al4V). The deposition process was carried out by the pulse current technique at 70 °C from electrolyte containing the appropriate amount of Ca(NO{sub 3}){sub 2} and NH{sub 4}H{sub 2}PO{sub 4} components. During the electrochemical deposition Ag{sup +} and Zn{sup 2+} ions were introduced into the solution. The electrochemical behaviour and corrosion rate of the bioceramic coatings were investigated by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) measurements in conventional Ringer's solution in a three electrode open cell. The coating came into contact with the electrolyte and corrosion occurred during immersion. In order to achieve antimicrobial properties, it is important to maintain a continuous release of silver ions into physiological media, while the bioactive CaP layer enhances the biocompatibility properties of the layer by fostering the bone cell growth. The role of Zn{sup 2+} is to shorten wound healing time. Morphology and composition of coatings were studied by Scanning Electron Microscopy, Transmission Electron Microscopy and Energy-dispersive X-ray spectroscopy. Differential thermal analyses (DTA) were performed to determine the thermal stability of the pure and modified CaP bioceramic coatings while the structure and phases of the layers were characterized by X-ray diffraction (XRD) measurements. - Highlights: • Ag and Zn doped calcium phosphate (CaP) layers were electrochemically deposited. • Layer degradation was studied by EIS and potentiodynamic measurements. • The bioceramic coatings became passive after a period of immersion time. • Ag and Zn modified layer shows higher degradation rate compared to pure CaP coating.

  3. Transition Metal Ion Implantation into Diamond-Like Carbon Coatings: Development of a Base Material for Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Andreas Markwitz

    2015-01-01

    Full Text Available Micrometre thick diamond-like carbon (DLC coatings produced by direct ion deposition were implanted with 30 keV Ar+ and transition metal ions in the lower percentage (<10 at.% range. Theoretical calculations showed that the ions are implanted just beneath the surface, which was confirmed with RBS measurements. Atomic force microscope scans revealed that the surface roughness increases when implanted with Ar+ and Cu+ ions, whereas a smoothing of the surface from 5.2 to 2.7 nm and a grain size reduction from 175 to 93 nm are measured for Ag+ implanted coatings with a fluence of 1.24×1016 at. cm−2. Calculated hydrogen and carbon depth profiles showed surprisingly significant changes in concentrations in the near-surface region of the DLC coatings, particularly when implanted with Ag+ ions. Hydrogen accumulates up to 32 at.% and the minimum of the carbon distribution is shifted towards the surface which may be the cause of the surface smoothing effect. The ion implantations caused an increase in electrical conductivity of the DLC coatings, which is important for the development of solid-state gas sensors based on DLC coatings.

  4. Esophageal replacement.

    Science.gov (United States)

    Kunisaki, Shaun M; Coran, Arnold G

    2017-04-01

    This article focuses on esophageal replacement as a surgical option for pediatric patients with end-stage esophageal disease. While it is obvious that the patient׳s own esophagus is the best esophagus, persisting with attempts to retain a native esophagus with no function and at all costs are futile and usually detrimental to the overall well-being of the child. In such cases, the esophagus should be abandoned, and the appropriate esophageal replacement is chosen for definitive reconstruction. We review the various types of conduits used for esophageal replacement and discuss the unique advantages and disadvantages that are relevant for clinical decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Comparison of 1-Year Outcome in Patients With Severe Aorta Stenosis Treated Conservatively or by Aortic Valve Replacement or by Percutaneous Transcatheter Aortic Valve Implantation (Data from a Multicenter Spanish Registry).

    Science.gov (United States)

    González-Saldivar, Hugo; Rodriguez-Pascual, Carlos; de la Morena, Gonzalo; Fernández-Golfín, Covadonga; Amorós, Carmen; Alonso, Mario Baquero; Dolz, Luis Martínez; Solé, Albert Ariza; Guzmán-Martínez, Gabriela; Gómez-Doblas, Juan José; Jiménez, Antonio Arribas; Fuentes, María Eugenia; Gay, Laura Galian; Ortiz, Martin Ruiz; Avanzas, Pablo; Abu-Assi, Emad; Ripoll-Vera, Tomás; Díaz-Castro, Oscar; Osinalde, Eduardo P; Martínez-Sellés, Manuel

    2016-07-15

    The factors that influence decision making in severe aortic stenosis (AS) are unknown. Our aim was to assess, in patients with severe AS, the determinants of management and prognosis in a multicenter registry that enrolled all consecutive adults with severe AS during a 1-month period. One-year follow-up was obtained in all patients and included vital status and aortic valve intervention (aortic valve replacement [AVR] and transcatheter aortic valve implantation [TAVI]). A total of 726 patients were included, mean age was 77.3 ± 10.6 years, and 377 were women (51.8%). The most common management was conservative therapy in 468 (64.5%) followed by AVR in 199 (27.4%) and TAVI in 59 (8.1%). The strongest association with aortic valve intervention was patient management in a tertiary hospital with cardiac surgery (odds ratio 2.7, 95% confidence interval 1.8 to 4.1, p <0.001). The 2 main reasons to choose conservative management were the absence of significant symptoms (136% to 29.1%) and the presence of co-morbidity (128% to 27.4%). During 1-year follow-up, 132 patients died (18.2%). The main causes of death were heart failure (60% to 45.5%) and noncardiac diseases (46% to 34.9%). One-year survival for patients treated conservatively, with TAVI, and with AVR was 76.3%, 94.9%, and 92.5%, respectively, p <0.001. One-year survival of patients treated conservatively in the absence of significant symptoms was 97.1%. In conclusion, most patients with severe AS are treated conservatively. The outcome in asymptomatic patients managed conservatively was acceptable. Management in tertiary hospitals is associated with valve intervention. One-year survival was similar with both interventional strategies.

  6. The adsorption and lubrication behavior of synovial fluid proteins and glycoproteins on the bearing-surface materials of hip replacements.

    Science.gov (United States)

    Roba, Marcella; Naka, Marco; Gautier, Emanuel; Spencer, Nicholas D; Crockett, Rowena

    2009-04-01

    The selectivity of synovial fluid protein adsorption onto ultra-high molecular weight polyethylene (UHMWPE) and alumina (Al(2)O(3)), and in particular the ability of glycoproteins to adsorb in the presence of all the other synovial fluid proteins, was investigated by means of fluorescence microscopy and gel electrophoresis (SDS-PAGE). The non-specific nature of protein adsorption from synovial fluid indicated that the lubrication of artificial hip-joint materials may not be attributable to a single protein as has been frequently suggested. The friction behavior of polyethylene (PE) sliding against Al(2)O(3) in solutions of bovine serum albumin (BSA), alpha-1-acid glycoprotein (AGP) and alpha-1-antitrypsin (A1AT) was investigated by means of colloidal probe atomic force microscopy. BSA was shown to be a poorer boundary lubricant than the phosphate buffered saline used as a control. This was attributed to denaturation of the BSA upon adsorption, which provided a high-shear-strength layer at the interface, impairing the lubrication. Interestingly, both the glycoproteins AGP and A1AT, despite their low concentrations, improved lubrication. The lubricating properties of AGP and A1AT were attributed to adsorption via the hydrophobic backbone, allowing the hydrophilic carbohydrate moieties to be exposed to the aqueous solution, thus providing a low-shear-strength fluid film that lubricated the system. The amount of glycoprotein adsorbed on hydrophobic surfaces was determined by means of optical waveguide lightmode spectroscopy (OWLS), allowing conclusions to be drawn about the conformation of the glycan residues following adsorption.

  7. Midterm Results of Aortic Valve Replacement with Cryopreserved Homografts

    Directory of Open Access Journals (Sweden)

    Emre Özker

    2012-06-01

    Full Text Available Objective: The aim of this study was to analyze the midterm clinical results of aortic valve replacement with cryopreserved homografts.Materials and Methods: Aortic valve replacement was performed in 40 patients with cryopreserved homograft. The indications were aortic valve endocarditis in 20 patients (50%, truncus arteriosus in 6 patients (15%, and re-stenosis or regurtitation after aortic valve reconstruction in 14 (35% patients. The valve sizes ranged from 10 to 27mm. A full root replacement technique was used for homograft replacement in all patients.Results: The 30-day postoperative mortality rate was 12.5% (5 patients. There were four late deaths. Only one of them was related to cardiac events. Overall mortality was 22.5%. Thirty-three patients were followed up for 67±26 months. Two patients needed reoperation due to aortic aneurysm caused by endocarditis. The mean transvalvular gradient significantly decreased after valve replacement (p<0.003. The last follow up showed that the 27 (82% patients had a normal left ventricular function.Conclusion: Cryopreserved homografts are safe alternatives to mechanical valves that can be used when there are proper indications. Although it has a high perioperative mortality rate, cryopreserved homograft implantation is an alternative for valve replacement, particularly in younger patients and for complex surgical problems such as endocarditis that must be minimalized.

  8. Fulminant diffuse systemic sclerosis following aortic valve replacement.

    Science.gov (United States)

    Marasovic-Krstulovic, Daniela; Jurisic, Zrinka; Perkovic, Dijana; Aljinovic, Jure; Martinovic-Kaliterna, Dusanka

    2014-06-01

    We present a case of fulminant diffuse systemic sclerosis (dSSc) developed after the aortic valve replacement followed by fatal congestive heart failure within the 6 months from the initial symptoms. A 61-year-old male developed rapidly progressive diffuse systemic sclerosis following aortic valve replacement due to stenosis of bicuspid aortic valve. He presented with diarrhoea, weight loss, mialgia and arthralgia after cardiac surgery. Heart failure, due to myocardial fibrosis, was noted as a cause of death. We hypothesize that artificial materials like the ones used in mechanical valves or silicon materials in breast implants may induce fulminant course of pre-existing systemic sclerosis or create a new onset in predisposed individual.

  9. A histological investigation on tissue responses to titanium implants in cortical bone of the rat femur.

    Science.gov (United States)

    Ohtsu, A; Kusakari, H; Maeda, T; Takano, Y

    1997-03-01

    Implant materials are placed under various sites-including cortical bone, spongy bone, and bone marrow-at the same time according to the depth at implantation. Although cortical bone is an important site for the prognosis of implantation, detailed reports on tissue responses to implantation have been meager. The present study aims to reveal tissue responses to pure titanium implantation in rat femoris cortical bone. The rats received titanium bars surgically in their femurs and were sacrificed 1 day to 40 weeks post-implantation. The prepared tissue specimens were processed for light and transmission electron microscopy (TEM). Further histochemical detections were performed. One day post-implantation, empty osteocytic lacunae indicating degeneration of osteocytes were found in pre-existing cortical bone around the implant. Such pre-existing bone was replaced by new bone, but remained in part even 40 weeks post-implantation. Light microscopy showed that direct contact between the implant and new bone was identified 12 weeks post-implantation. Chronological and ultrastructural observation showed that new bone deposition appeared to proceed toward the implant, and that the intervening layer at the interface was derived from the degenerated debris of multinucleated giant cells and/or osteoblasts. Furthermore, it seemed that the width of intervening layer varied in relation to the distance from the blood vessels. The cells showing tartrate resistant acid phosphatase activity possessed cytological features of osteoclasts under TEM; they were frequently observed in perivascular sites near the implants even after osseointegration, suggesting that bone remodeling took place steadily around the implant.

  10. Three-dimensional finite element analysis of platform switched implant

    Science.gov (United States)

    2017-01-01

    PURPOSE The purpose of this study was to analyze the influence of the platform switching concept on an implant system and peri-implant bone using three-dimensional finite element analysis. MATERIALS AND METHODS Two three-dimensional finite element models for wide platform and platform switching were created. In the wide platform model, a wide platform abutment was connected to a wide platform implant. In the platform switching model, the wide platform abutment of the wide platform model was replaced by a regular platform abutment. A contact condition was set between the implant components. A vertical load of 300 N was applied to the crown. The maximum von Mises stress values and displacements of the two models were compared to analyze the biomechanical behavior of the models. RESULTS In the two models, the stress was mainly concentrated at the bottom of the abutment and the top surface of the implant in both models. However, the von Mises stress values were much higher in the platform switching model in most of the components, except for the bone. The highest von Mises values and stress distribution pattern of the bone were similar in the two models. The components of the platform switching model showed greater displacement than those of the wide platform model. CONCLUSION Due to the stress concentration generated in the implant and the prosthodontic components of the platform switched implant, the mechanical complications might occur when platform switching concept is used. PMID:28243389

  11. Argus II retinal prosthesis implantation with scleral flap and autogenous temporalis fascia as alternative patch graft material: a 4-year follow-up

    Science.gov (United States)

    Matet, Alexandre; Amar, Nawel; Mohand-Said, Saddek; Sahel, José-Alain; Barale, Pierre-Olivier

    2016-01-01

    Introduction The Argus II retinal prosthesis is composed of an epiretinal electrode array positioned over the macula and connected to an extrascleral electronics case via a silicone cable, running through a sclerotomy. During implantation, the manufacturer recommends to cover the sclerotomy site with a patch of processed human pericardium to prevent postoperative hypotony and conjunctival erosion by the underlying electronics case. Due to biomedical regulations prohibiting the use of this material in France, we developed an alternative technique combining a scleral flap protecting the sclerotomy and an autogenous graft of superior temporalis fascia overlying the electronics case. Methods The purpose of this study is to describe the 4-year outcomes of this modified procedure in three subjects who underwent Argus II Retinal Prosthesis System implantation. Clinical data consisting of intraocular pressure measurements and tolerance in terms of conjunctival erosion or inflammation were retrospectively assessed over a 4-year postoperative follow-up. Results None of the three patients implanted with the modified technique developed ocular hypotony over 4 years. A normal, transient conjunctival inflammation occurred during the first postoperative month but conjunctival erosion was not observed in any of the three patients over 4 years. Four years after implantation, the autogenous temporalis fascia graft remained well tolerated and the retinal prosthesis was functional in all three patients. Conclusion The combination of an autograft of superficial temporalis fascia and a scleral flap efficiently prevented leakage through the sclerotomy site, ocular hypotony, and conjunctival erosion by the extrascleral electronics case. This modified technique is suitable for the implantation of existing and forthcoming retinal prostheses. Superficial temporalis fascia may also be used as alternative to commercial tectonic tissues for scleral wound repair in clinical settings where they

  12. Surface mechanical properties, corrosion resistance, and cytocompatibility of nitrogen plasma-implanted nickel-titanium alloys: a comparative study with commonly used medical grade materials.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Chu, P K; Chung, C Y; Liu, X Y; Lu, W W; Chan, D; Chan, S C W; Luk, K D K; Cheung, K M C

    2007-08-01

    Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants.

  13. [Regeneration processes in bone defects after implantation of composite material of different density of polylactide origin filled with HAP (experimental-morphological study)].

    Science.gov (United States)

    Kulakov, A A; Grigor'ian, A S; Krotova, L I; Popov, V K; Volozhin, A I; Losev, V F

    2009-01-01

    In experimental-morphological study on 6 dogs the dynamics of regenerate formation in ulna and mandible defects after implantation in them composite material of different density (0.46-0.50 and 0.38-0.42 g/cm(3)) of polylactide (PL) origin filled with HAP was followed at the terms of 6 and 9 months. Histologic study and structural determinant distribution analysis in the content of regenerate showed that optimal results according to the bone defect substitution by bone regenerate criterion at 9th month of the experiment were received after composite material from PL and HAP with the density of 0.38-0.42 g/cm(3) implantation. Newly formed trabecular bone tissue was seen in the regenerate and as well as strong tendency for bone matrix maturation. It was confirmed by the appearance of lamellar structures in newly formed bone trabecules situated in peripheral zones of bone defect. In bone mandible defects the substitution process of the implants from PL with HAP by the bone tissue was much slower than in ulna defects.

  14. Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

    Directory of Open Access Journals (Sweden)

    Bill G. X. Zhang

    2014-07-01

    Full Text Available Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants.

  15. Our Experience with Short Stem Hip Replacement Surgery

    Directory of Open Access Journals (Sweden)

    Sumeet Rastogi

    2016-07-01

    Full Text Available Context- A short anatomical metaphyseal femoral stem is a desirable hip implant for bone and soft tissue preserving hip replacing surgery in young arthritic patients. Physiological loading of the proximal femur prevents stress shielding and preserves bone stock of the femur in the long run. Thus it is an ideal hip implant suited for conservative hip surgeries in active young adults with arthritic hips. Materials and methods- 50 Proxima hip replacements were performed on 41 patients with a mean age of 45 over a 3-year period (between July 2006 and September 2009. Diagnosis of hip pathologies varied from osteoarthritis secondary to avascular necrosis, rheumatoid arthritis, post-tubercular arthritis to dysplastic hips. 9 of these patients had symptomatic bilateral hip involvement and underwent bilateral hip replacement in a single sitting. All patient had a Proxima metaphyseal stem implantation( DePuy, Warsaw with either a large diameter metal on metal or pinnacle articulation. Clinical and radiological evaluation was done at 3 months, 6 months, 1 year and then yearly thereafter. Statiscal analysis used- VAS and Harris hip score formed the basis of evaluation Results- These patients were followed up for a mean period of 49 months (Range 36-72 months. The average incision size was 14.38 cm (10-18 cm and blood loss was 269 ml (175-450 ml. There was no peri-operative mortality or serious morbidity in any patients. One patient had an intraoperative lateral cortex crack that required only delayed rehabilitation. Five of the 41 patients (12.1 % had complications with three recovering completely and one requiring revision of femoral stem for aseptic loosening. One patient was lost in follow-up. Harris hip score improved from 52 to 89.3 at last follow-up. Overall 95.1% (39/41 patients had an excellent outcome at last follow-up. Conclusion- We conclude that Proxima metaphyseal stem provided clinically and radiologically stable fixation through snug fit

  16. Dental implants: A review.

    Science.gov (United States)

    Guillaume, B

    2016-12-01

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

  17. [Mandibular bone tissue regeneration after the introduction of the implantation system performed on the basis of carbon composite material].

    Science.gov (United States)

    Chetvertnykh, V A; Loginova, N P; Astashina, N B; Rogozhnikov, G I; Rapekta, S I

    2013-01-01

    The purpose of this study was to investigate the processes of regeneration of bone tissue after the introduction of new implant systems. In the experiment, performed on 10 male pigs of Landras breed aged 50-55 days and weighing 17-18.5 kg, the time course of histological changes was studied in the area of mandibular regeneration after the formation of tissue defect and the introduction of the implant of a proposed construction. Morphological analysis of the experimental results 90, 180 and 270 days after the operation demonstrated the process of reparative regeneration of damaged bone along implant-bone block boundaries. Bone repair proceeded through the stage of formation of the woven bone with its progressive substitution by the lamellar bone, with the maintenance of the shape, size and symmetry of the damaged organ.

  18. Subgingival microbiome in patients with healthy and ailing dental implants

    OpenAIRE

    Hui Zheng; Lixin Xu; Zicheng Wang; Lianshuo Li; Jieni Zhang; Qian Zhang; Ting Chen; Jiuxiang Lin; Feng Chen

    2015-01-01

    Dental implants are commonly used to replace missing teeth. However, the dysbiotic polymicrobial communities of peri-implant sites are responsible for peri-implant diseases, such as peri-implant mucositis and peri-implantitis. In this study, we analyzed the microbial characteristics of oral plaque from peri-implant pockets or sulci of healthy implants (n = 10), peri-implant mucositis (n = 8) and peri-implantitis (n = 6) sites using pyrosequencing of the 16S rRNA gene. An increase in microbial...

  19. Medical characteristics of degradable magnesium alloy as medical implant materials%生物可降解镁合金植入材料的医用特征

    Institute of Scientific and Technical Information of China (English)

    姜海英; 艾红军

    2011-01-01

    BACKGROUND: Magnesium and magnesium alloys as new medical implant materials are a hotspot of biodegradable materials in recent years, including alloying, biocompatibility, surface modification coatings, which have a great progress.OBJECTIVE: To summarize the present situation of domestic and international magnesium and magnesium alloy as medical implant materials.METHODS: A computer retrieval of CNKI and PubMed database 1998-01/2010-10 for articles about magnesium and magnesium alloy was conducted. In the title and abstract, “metal matrix biological materials; medical implant materials;magnesium alloy; biodegradable; bone; biocompatibility” were used. Finally, 41 articles were reviewed in this article.RESULTS AND CONCLUSION: Magnesium and magnesium alloys as new medical implant material with excellent mechanical properties and biodegradability are attracting more and more researchers' attention. But poor corrosion resistant performance of magnesium and magnesium alloy affects clinical applications. In order to improve the corrosion resistant performance, the researchers have performed magnesium and magnesium alloy surface treatment and made important progress. Magnesium and magnesium alloy are applied widely in biomedical metal implant material field.%背景:镁及镁合金作为新型医用植入材料是近年来生物可降解材料的一个研究热点,其中合金化、生物相容性、表面改性涂层研究都有了很大进展.目的:对国内外镁及镁合金医用植入材料的研究现状及新进展作一综述.方法:应用计算机检索CNKI和Pubmed数据库中1998-01/2010-10关于镁及镁合金的文章,在标题和摘要中以"金属基生物材料; 医用植入材料;镁合金;生物可降解;骨;生物相容性"或"metal matrix biomaterials;medical implant materials; magnesium alloy; biodegradable; bone; biocompatibility "为检索词进行检索.选择关于镁及镁合金的41篇文献进行综述.结果与结论:镁及镁合金作为

  20. A new organic reference material, L-glutamic acid, USGS41a, for δ13C and δ15N measurements − a replacement for USGS41

    Science.gov (United States)

    Qi, Haiping; Coplen, Tyler B.; Mroczkowski, Stanley J.; Brand, Willi A.; Brandes, Lauren; Geilmann, Heike; Schimmelmann, Arndt

    2016-01-01

    RationaleThe widely used l-glutamic acid isotopic reference material USGS41, enriched in both 13C and 15N, is nearly exhausted. A new material, USGS41a, has been prepared as a replacement for USGS41.MethodsUSGS41a was prepared by dissolving analytical grade l-glutamic acid enriched in 13C and 15N together with l-glutamic acid of normal isotopic composition. The δ13C and δ15N values of USGS41a were directly or indirectly normalized with the international reference materials NBS 19 calcium carbonate (δ13CVPDB = +1.95 mUr, where milliurey = 0.001 = 1 ‰), LSVEC lithium carbonate (δ13CVPDB = −46.6 mUr), and IAEA-N-1 ammonium sulfate (δ15NAir = +0.43 mUr) and USGS32 potassium nitrate (δ15N = +180 mUr exactly) by on-line combustion, continuous-flow isotope-ratio mass spectrometry, and off-line dual-inlet isotope-ratio mass spectrometry.ResultsUSGS41a is isotopically homogeneous; the reproducibility of δ13C and δ15N is better than 0.07 mUr and 0.09 mUr, respectively, in 200-μg amounts. It has a δ13C value of +36.55 mUr relative to VPDB and a δ15N value of +47.55 mUr relative to N2 in air. USGS41 was found to be hydroscopic, probably due to the presence of pyroglutamic acid. Experimental results indicate that the chemical purity of USGS41a is substantially better than that of USGS41.ConclusionsThe new isotopic reference material USGS41a can be used with USGS40 (having a δ13CVPDB value of −26.39 mUr and a δ15NAir value of −4.52 mUr) for (i) analyzing local laboratory isotopic reference materials, and (ii) quantifying drift with time, mass-dependent isotopic fractionation, and isotope-ratio-scale contraction for isotopic analysis of biological and organic materials. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.

  1. A new organic reference material, l-glutamic acid, USGS41a, for δ(13) C and δ(15) N measurements - a replacement for USGS41.

    Science.gov (United States)

    Qi, Haiping; Coplen, Tyler B; Mroczkowski, Stanley J; Brand, Willi A; Brandes, Lauren; Geilmann, Heike; Schimmelmann, Arndt

    2016-04-15

    The widely used l-glutamic acid isotopic reference material USGS41, enriched in both (13) C and (15) N, is nearly exhausted. A new material, USGS41a, has been prepared as a replacement for USGS41. USGS41a was prepared by dissolving analytical grade l-glutamic acid enriched in (13) C and (15) N together with l-glutamic acid of normal isotopic composition. The δ(13) C and δ(15) N values of USGS41a were directly or indirectly normalized with the international reference materials NBS 19 calcium carbonate (δ(13) CVPDB = +1.95 mUr, where milliurey = 0.001 = 1 ‰), LSVEC lithium carbonate (δ(13) CVPDB = -46.6 mUr), and IAEA-N-1 ammonium sulfate (δ(15) NAir = +0.43 mUr) and USGS32 potassium nitrate (δ(15) N = +180 mUr exactly) by on-line combustion, continuous-flow isotope-ratio mass spectrometry, and off-line dual-inlet isotope-ratio mass spectrometry. USGS41a is isotopically homogeneous; the reproducibility of δ(13) C and δ(15) N is better than 0.07 mUr and 0.09 mUr, respectively, in 200-μg amounts. It has a δ(13) C value of +36.55 mUr relative to VPDB and a δ(15) N value of +47.55 mUr relative to N2 in air. USGS41 was found to be hydroscopic, probably due to the presence of pyroglutamic acid. Experimental results indicate that the chemical purity of USGS41a is substantially better than that of USGS41. The new isotopic reference material USGS41a can be used with USGS40 (having a δ(13) CVPDB value of -26.39 mUr and a δ(15) NAir value of -4.52 mUr) for (i) analyzing local laboratory isotopic reference materials, and (ii) quantifying drift with time, mass-dependent isotopic fractionation, and isotope-ratio-scale contraction for isotopic analysis of biological and organic materials. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.

  2. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis.

    Science.gov (United States)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten; Gotfredsen, Klaus

    2013-10-01

    The purpose of this clinical study was to describe outcome variables of all-ceramic and metal-ceramic implant-supported, single-tooth restorations. A total of 59 patients (mean age: 27.9 years) with tooth agenesis and treated with 98 implant-supported single-tooth restorations were included in this study. Two patients did not attend baseline examination, but all patients were followed for 3 years. The implants supported 52 zirconia, 21 titanium and 25 gold alloy abutments, which retained 64 all-ceramic and 34 metal-ceramic crowns. At baseline and 3-year follow-up examinations, the biological outcome variables such as survival rate of implants, marginal bone level, modified Plaque Index (mPlI), modified Sulcus Bleeding Index (mBI) and biological complications were registered. The technical outcome variables included abutment and crown survival rate, marginal adaptation of crowns, cement excess and technical complications. The aesthetic outcome was assessed by using the Copenhagen Index Score, and the patient-reported outcomes were recorded using the OHIP-49 questionnaire. The statistical analyses were mainly performed by using mixed model of ANOVA for quantitative data and PROC NLMIXED for ordinal categorical data. The 3-year survival rate was 100% for implants and 97% for abutments and crowns. Significantly more marginal bone loss was registered at gold-alloy compared to zirconia abutments (P = 0.040). The mPlI and mBI were not significantly different at three abutment materials. The frequency of biological complications was higher at restorations with all-ceramic restorations than metal-ceramic crowns. Loss of retention, which was only observed at metal-ceramic crowns, was the most frequent technical complication, and the marginal adaptations of all-ceramic crowns were significantly less optimal than metal-ceramic crowns (P = 0.020). The professional-reported aesthetic outcome demonstrated significantly superior colour match of all-ceramic over metal

  3. Survival of dental implants placed in sites of previously failed implants.

    Science.gov (United States)

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

    2016-10-14

    To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Influence of geometry and materials on the axial and torsional strength of the head-neck taper junction in modular hip replacements: A finite element study.

    Science.gov (United States)

    Fallahnezhad, Khosro; Farhoudi, Hamidreza; Oskouei, Reza H; Taylor, Mark

    2016-07-01

    The assembly force is important in establishing the mechanical environment at the head-neck taper junction of modular hip replacements. Previous experimental results of the assembled taper junctions with different material combinations (Co-28Cr-6Mo and Ti-6Al-4V) reported similar axial strengths (pull-off loads), but lower torsional strengths (twist-off moments) for the CoCr/CoCr junction. However, mechanics of the junction and the strength behaviour have not been understood yet. A three dimensional finite element model of an isolated femoral head-neck junction was developed to explore the assembly and disassembly procedures, particularly the axial and torsional strengths for different material combinations and geometries. Under the same assembly load, the contacting length between the CoCr head and titanium neck was greater than that of in CoCr/CoCr. The contact length in the titanium neck was more sensitive to the assembly force when compared to the CoCr neck. For instance, with increasing the assembly force from 1890 to 3700N, the contact length increased by 88% for CoCr/Ti and 59% for CoCr/CoCr junctions. The torsional strength of the junction was related to the lateral deformation of the neck material due to the applied moment. The angular mismatch existing between the head and neck components was found to play the main role in the torsional strength of the junction. The smaller mismatch angle the higher torsional strength. It is suggested to consider reducing the mismatch angle, particularly in CoCr/CoCr junctions, and ensure a sufficiently high assembly force is applied by impaction for this combination.

  5. [Left Ventricular Rupture during Both Mitral and Aortic Valve Replacements].

    Science.gov (United States)

    Kurumisawa, Soki; Aizawa, Kei; Takazawa, Ippei; Sato, Hirotaka; Muraoka, Arata; Ohki, Shinnichi; Saito, Tsutomu; Kawahito, Koji; Misawa, Yoshio

    2015-05-01

    A 73-year-old woman on hemodialysis was transferred to our hospital for surgical treatment of heart valve disease. She required both mitral and aortic valve replacement with mechanical valves, associated with tricuspid annuloplasty. After aortic de-clamping, a massive hemorrhage from the posterior atrioventricular groove was observed. Under repeated cardiac arrest, the left atrium was reopened, the implanted mitral prosthetic valve was removed and a type I left ventricular rupture (Treasure classification) was diagnosed. The lesion was directly repaired with mattress stitches and running sutures, using reinforcement materials such as a glutaraldehyde-treated bovine pericardium. To avoid mechanical stress by the prosthetic valve on the repaired site, a mechanical valve was implanted using a translocation method. The patient suffered from aspiration pneumonia and disuse atrophy for 3 months. However, she was doing well at 1 year post-operation.

  6. Dental implants in growing children

    Directory of Open Access Journals (Sweden)

    S K Mishra

    2013-01-01

    Full Text Available The replacement of teeth by implants is usually restricted to patients with completed craniofacial growth. The aim of this literature review is to discuss the use of dental implants in normal growing patients and in patients with ectodermal dysplasia and the influence of maxillary and mandibular skeletal and dental growth on the stability of those implants. It is recommended that while deciding the optimal individual time point of implant insertion, the status of skeletal growth, the degree of hypodontia, and extension of related psychological stress should be taken into account, in addition to the status of existing dentition and dental compliance of a pediatric patient.

  7. Aspirin Versus Aspirin Plus Clopidogrel as Antithrombotic Treatment Following Transcatheter Aortic Valve Replacement With a Balloon-Expandable Valve: The ARTE (Aspirin Versus Aspirin + Clopidogrel Following Transcatheter Aortic Valve Implantation) Randomized Clinical Trial.

    Science.gov (United States)

    Rodés-Cabau, Josep; Masson, Jean-Bernard; Welsh, Robert C; Garcia Del Blanco, Bruno; Pelletier, Marc; Webb, John G; Al-Qoofi, Faisal; Généreux, Philippe; Maluenda, Gabriel; Thoenes, Martin; Paradis, Jean-Michel; Chamandi, Chekrallah; Serra, Vicenç; Dumont, Eric; Côté, Mélanie

    2017-07-10

    The aim of this study was to compare aspirin plus clopidogrel with aspirin alone as antithrombotic treatment following transcatheter aortic valve replacement (TAVR) for the prevention of ischemic events, bleeding events, and death. Few data exist on the optimal antithrombotic therapy following TAVR. This was a randomized controlled trial comparing aspirin (80 to 100 mg/day) plus clopidogrel (75 mg/day) (dual antiplatelet therapy [DAPT]) versus aspirin alone (single-antiplatelet therapy [SAPT]) in patients undergoing TAVR with a balloon-expandable valve. The primary endpoint was the occurrence of death, myocardial infarction (MI), stroke or transient ischemic attack, or major or life-threatening bleeding (according to Valve Academic Research Consortium 2 definitions) within the 3 months following the procedure. The trial was prematurely stopped after the inclusion of 74% of the planned study population. A total of 222 patients were included, 111 allocated to DAPT and 111 to SAPT. The composite of death, MI, stroke or transient ischemic attack, or major or life-threatening bleeding tended to occur more frequently in the DAPT group (15.3% vs. 7.2%, p = 0.065). There were no differences between groups in the occurrence of death (DAPT, 6.3%; SAPT, 3.6%; p = 0.37), MI (DAPT, 3.6%; SAT, 0.9%; p = 0.18), or stroke or transient ischemic attack (DAPT, 2.7%; SAPT, 0.9%; p = 0.31) at 3 months. DAPT was associated with a higher rate of major or life-threatening bleeding events (10.8% vs. 3.6% in the SAPT group, p = 0.038). There were no differences between groups in valve hemodynamic status post-TAVR. This small trial showed that SAPT (vs. DAPT) tended to reduce the occurrence of major adverse events following TAVR. SAPT reduced the risk for major or life-threatening events while not increasing the risk for MI or stroke. Larger studies are needed to confirm these results. (Aspirin Versus Aspirin + Clopidogrel Following Transcatheter Aortic Valve Implantation: The ARTE

  8. A three-dimensional finite element analysis of a passive and friction fit implant abutment interface and the influence of occlusal table dimension on the stress distribution pattern on the implant and surrounding bone

    OpenAIRE

    Sarfaraz, Hasan; Paulose, Anoopa; Shenoy, K. Kamalakanth; Hussain, Akhter

    2015-01-01

    Aims: The aim of the study was to evaluate the stress distribution pattern in the implant and the surrounding bone for a passive and a friction fit implant abutment interface and to analyze the influence of occlusal table dimension on the stress generated. Materials and Methods: CAD models of two different types of implant abutment connections, the passive fit or the slip-fit represented by the Nobel Replace Tri-lobe connection and the friction fit or active fit represented by the Nobel activ...

  9. Assessment of modified gold surfaced titanium implants on skeletal fixation

    DEFF Research Database (Denmark)

    Zainali, Kasra; Danscher, Gorm; Jakobsen, Thomas

    2013-01-01

    Noncemented implants are the primary choice for younger patients undergoing total hip replacements. However, the major concern in this group of patients regarding revision is the concern from wear particles, periimplant inflammation, and subsequently aseptic implant loosening. Macrophages have be...

  10. Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars; Avaliacao da lama vermelha como material pozolanico em substituicao ao cimento para producao de argamassas

    Energy Technology Data Exchange (ETDEWEB)

    Manfroi, E.P.; Cheriaf, M.; Rocha, J.C., E-mail: elizmanfroi@yahoo.com.b, E-mail: malik@valores.ufsc.b [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Civil

    2010-07-01

    Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

  11. A survey on the use of techniques, materials in dental implantology practice

    Directory of Open Access Journals (Sweden)

    R Chowdhary

    2012-01-01

    Full Text Available Purpose: To present results of a survey on the status of an implantology amongst implant-practicing dentist across the world in 2009. Materials and Methods: A questionnaire was sent to the members of EAO (European Association of Osseointegration, ICOI (International Congress of Osseointegrated Implants, ISOI (Indian Society of Oral Implantologists, Asian Academy of Osseointegration (AAO, Deutsche Gasellschaft Fur Orale Implantologie (DGOI, Philippines Implant Organization, Korean Society of Oral Implantologist, Japanese Association of OralIimplantologists, Chinese Dental Association, Pakistan Dental Association, asking for the personal (anonymous background data and their implantology concepts. Specific questions dealt with level of recognition of implants, use of implants, superstructures, techniques followed, and materials used. Results: A total of 1500 (63.6% of the 2358 questionnaires were answered. Dental implants were the most preferred treatment modality for restoring the missing teeth. Threaded implants were the most preferred. Cement retained implant prosthesis was the most preferred restoration procedure. Dentists believe that the general dentist should practice dental implant treatment modality, preferably teamwork. Immediate loading was the much-accepted concept among the dentists of the developed nations. Conclusion: Dental implants were much accepted treatment modality for the replacement of missing teeth. Most the dentists follow the well documented technique and proven materials, which have been documented in the literature, an evidenced based practice, thus, delivering the best to their patients. Dentists from the developing nations agreed to have standardization in implants.

  12. Anesthesia management for MitraClip device implantation

    Directory of Open Access Journals (Sweden)

    Harikrishnan Kothandan

    2014-01-01

    Full Text Available Aims and Objectives: Percutaneous MitraClip implantation has been demonstrated as an alternative procedure in high-risk patients with symptomatic severe mitral regurgitation (MR who are not suitable (or denied mitral valve repair/replacement due to excessive co morbidity. The MitraClip implantation was performed under general anesthesia and with 3-dimensional transesophageal echocardiography (TEE and fluoroscopic guidance. Materials and Methods: Peri-operative patient data were extracted from the electronic and paper medical records of 21 patients who underwent MitraClip implantations. Results: Four MitraClip implantation were performed in the catheterization laboratory; remaining 17 were performed in the hybrid operating theatre. In 2 patients, procedure was aborted, in one due to migration of the Chiari network into the left atrium and in second one, the leaflets and chords of the mitral valve torn during clipping resulting in consideration for open surgery. In the remaining 19 patients, MitraClip was implanted and the patients showed acute reduction of severe MR to mild-moderate MR. All the patients had invasive blood pressure monitoring and the initial six patients had central venous catheterization prior to the procedure. Intravenous heparin was administered after the guiding catheter was introduced through the inter-atrial septum and activated clotting time was maintained beyond 250 s throughout the procedure. Protamine was administered at the end of the procedure. All the patients were monitored in the intensive care unit after the procedure. Conclusions: Percutaneous MitraClip implantation is a feasible alternative in high-risk patients with symptomatic severe MR. Anesthesia management requirements are similar to open surgical mitral valve repair or replacement. TEE plays a vital role during the MitraClip implantation.

  13. Endodontic therapy or single tooth implant? A systematic review.

    Science.gov (United States)

    Torabinejad, Mahmoud; Lozada, Jaime; Puterman, Israel; White, Shane N

    2008-06-01

    Should a tooth with pulpal involvement be saved through endodontic therapy, or extracted and replaced with a single tooth implant? Within the limitations of the existing literature, this systematic review of treatment outcomes found that initial endodontic treatment had a high long-term survival rate, equivalent to replacement of a missing tooth with an implant-supported restoration. Single tooth implants should be considered as the first treatment option for patients requiring extraction and tooth replacement.

  14. A Radiographic Comparison of Progressive and Conventional Loading on Crestal Bone Loss and Density in Single Implants

    Directory of Open Access Journals (Sweden)

    Majid Sorouri

    2013-01-01

    Full Text Available Objectives: Crestal bone loss is a biologic complication in implant dentistry. The aim of this study was to compare the effect of progressive and conventional loading on crestal bone height and bone density around single osseointegrated implants in posterior maxilla by a longitudinal radiographic assessment technique.Materials and methods: Twenty micro thread implants were placed in 10 patients (two implants per patient. One of the two implants of each patient was assigned to progressive and the other to conventional loading groups. Eight weeks after surgery, conventional implants were restored with a metal ceramic crown and progressive group underwent a progressive loading protocol. The progressive loading group takes different temporary acrylic crowns at 2, 4 and 6 months. After eight months, acrylic crowns were replaced with metal ceramic crown. Computer radiography of both progressive and conventional implants was taken at 2, 4, 6, and 12 months. Image analysis was performed to measure height of crestal bone loss and bone density.Results: The mean values of crestal bone loss at month 12 were 0.11 (0.19 mm for progressively and 0.36 (0.36 mm for conventionally loaded implants, with a statistically significant difference (P 0.05.Conclusion: Progressive group showed less crestal bone loss in single osseointegrated implant than conventional group. Bone density around progressively loaded implants showed increase in crestal, middle and apica

  15. In vitro and in vivo biocompatibility and osteogenesis of graphene-reinforced nanohydroxyapatite polyamide66 ternary biocomposite as orthopedic implant material

    Science.gov (United States)

    Zhang, Shiyang; Yang, Qiming; Zhao, Weikang; Qiao, Bo; Cui, Hongwang; Fan, Jianjun; Li, Hong; Tu, Xiaolin; Jiang, Dianming

    2016-01-01

    Graphene and its derivatives have been receiving increasing attention regarding their application in bone tissue engineering because of their excellent characteristics, such as a vast specific surface area and excellent mechanical properties. In this study, graphene-reinforced nanohydroxyapatite/polyamide66 (nHA/PA66) bone screws were prepared. The results of scanning electron microscopy observation and X-ray diffraction data showed that both graphene and nHA had good dispersion in the PA66 matrix. In addition, the tensile strength and elastic modulus of the composites were significantly improved by 49.14% and 21.2%, respectively. The murine bone marrow mesenchymal stem cell line C3H10T1/2 exhibited better adhesion and proliferation in graphene reinforced nHA/PA66 composite material compared to the nHA/PA66 composites. The cells developed more pseudopods, with greater cell density and a more distinguishable cytoskeletal structure. These results were confirmed by fluorescent staining and cell viability assays. After C3H10T1/2 cells were cultured in osteogenic differentiation medium for 7 and 14 days, the bone differentiation-related gene expression, alkaline phosphatase, and osteocalcin were significantly increased in the cells cocultured with graphene reinforced nHA/PA66. This result demonstrated the bone-inducing characteristics of this composite material, a finding that was further supported by alizarin red staining results. In addition, graphene reinforced nHA/PA66 bone screws were implanted in canine femoral condyles, and postoperative histology revealed no obvious damage to the liver, spleen, kidneys, brain, or other major organs. The bone tissue around the implant grew well and was directly connected to the implant. The soft tissues showed no obvious inflammatory reaction, which demonstrated the good biocompatibility of the screws. These observations indicate that graphene-reinforced nHA/PA66 composites have great potential for application in bone tissue

  16. Dental Implant Systems

    Science.gov (United States)

    Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

    2010-01-01

    Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

  17. Dental Implant Systems

    Directory of Open Access Journals (Sweden)

    Yoshiki Oshida

    2010-04-01

    Full Text Available Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities.

  18. Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    Denmark, DenmarkAbstractReplacement of extensive local bone loss especially in revision joint arthroplasty and spine fusion is a significant clinical challenge. Allograft and autograft have been considered as gold standard for bone replacement. However, there are several disadvantages such as donor site...... from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants...... with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested...

  19. Argus II retinal prosthesis implantation with scleral flap and autogenous temporalis fascia as alternative patch graft material: a 4-year follow-up

    Directory of Open Access Journals (Sweden)

    Matet A

    2016-08-01

    Full Text Available Alexandre Matet,1,2 Nawel Amar,1,2 Saddek Mohand-Said,1–4 José-Alain Sahel,1–7 Pierre-Olivier Barale1,2 1INSERM and DHOS, CHNO des Quinze-Vingts, 2Sorbonne Universités, UPMC Univ Paris 6, Institut de la Vision, 3INSERM, 4CNRS, Paris, France; 5Institute of Ophthalmology, University College London, London, UK; 6Fondation Ophtalmologique Adolphe de Rothschild, 7Académie des Sciences, Institut de France, Paris, France Introduction: The Argus II retinal prosthesis is composed of an epiretinal electrode array positioned over the macula and connected to an extrascleral electronics case via a silicone cable, running through a sclerotomy. During implantation, the manufacturer recommends to cover the sclerotomy site with a patch of processed human pericardium to prevent postoperative hypotony and conjunctival erosion by the underlying electronics case. Due to biomedical regulations prohibiting the use of this material in France, we developed an alternative technique combining a scleral flap protecting the sclerotomy and an autogenous graft of superior temporalis fascia overlying the electronics case. Methods: The purpose of this study is to describe the 4-year outcomes of this modified procedure in three subjects who underwent Argus II Retinal Prosthesis System implantation. Clinical data consisting of intraocular pressure measurements and tolerance in terms of conjunctival erosion or inflammation were retrospectively assessed over a 4-year postoperative follow-up. Results: None of the three patients implanted with the modified technique developed ocular hypotony over 4 years. A normal, transient conjunctival inflammation occurred during the first postoperative month but conjunctival erosion was not observed in any of the three patients over 4 years. Four years after implantation, the autogenous temporalis fascia graft remained well tolerated and the retinal prosthesis was functional in all three patients. Conclusion: The combination of an

  20. Finite element analysis for dental implants subjected to thermal loads

    Directory of Open Access Journals (Sweden)

    Mohamad Reza Khalili

    2013-10-01

    Full Text Available   Background and Aims: Dental implants have been studied for replacement of missing teeth for many years. Productivity of implants is extremely related to the stability and resistance under applied loads and the minimum stress in jaw bone. The purpose of this study was to study numerically the 3D model of implant under thermal loads.   Materials and Methods: Bone and the ITI implant were modeled in “Solidworks” software. To obtain the exact model, the bone was assumed as a linear orthotropic material. The implant system, including implant, abutment, framewor