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Prosthesis
Kinds of Prosthesis Terms modified by Prosthesis Selected AbstractsPalatal Anchorage for the Retention of Interim Removable ProsthesesJOURNAL OF PROSTHODONTICS, Issue 8 2009Alberto J. Ambard DDS Abstract This paper describes a technique that involves the use of palatal implants to retain a maxillary interim prosthesis when extensive bone graft procedures are performed. The rationale is that some bone graft procedures require the removal of the denture flanges for graft success. Once the denture flanges are removed, the denture loses all its retention capabilities, making this lengthy interim phase difficult for the patient. While the use of palatal implants has been documented extensively, limited information is available to describe the use of palatal implants for prosthetic reasons. [source] Corrosion of Dental Magnet Attachments for Removable Prostheses on Teeth and ImplantsJOURNAL OF PROSTHODONTICS, Issue 4 2009Arne F. Boeckler DMD, Dr Med Dent Abstract Purpose: For a long time, the use of magnets for the anchorage of dental prostheses failed due to lack of biocompatibility and the magnets' high susceptibility to corrosion in the mouth. These facts make encapsulation of the magnetic alloy with a corrosion-resistant, tight, and functionally firm sealing necessary. Due to different products and analysis methods, it is not feasible to compare the findings for contemporary products with the sparse and rather old test results in the literature. Therefore, the aim of this study was the standardized control and the comparison of the corrosion behavior of modern magnetic attachments for use on teeth and dental implants. Materials and Methods: Thirty-seven components of magnetic attachments on implants and natural teeth from different alloys (NdFeB, SmCo, Ti, CrMoMnTiFe, etc.) as delivered by the manufacturers or fabricated according to their instructions were examined for their corrosion behavior using the statical immersion analysis (ISO 10271:2001). Four specimens of every product with the same design were used. An uncased SmCo magnet served as control. Analyses after 1, 4, 7, and 28 days of the storage in corrosion solution were made. The eluate was examined quantitatively on the alloy components of the respective component with the help of optical emission spectrometry (,g/cm2). The results were compared to the requirements of ISO standard 22674:2006. In addition, existing corrosion products were also defined in the solution after 28 days. The results were analyzed descriptively and statistically to determine possible significant differences (t -test and Mann-Whitney-Wilcoxon rank-sums test; p < 0.05). Results: Dissolved metal ions could be found on all tested products. The release after 1 and 4 days was different for all specimens. In the group of implant abutments, the highest ion release after 7 days was found (all measurements ,g/cm2): Fe (13.94, Magfit-IP-IDN dome type), Pd (1.53, Medical-anchor), Cr (1.32, Magfit-IP-IDN dome type), Ti (1.09, Magfit-IP-IDN abutment), Co (0.81, Medical-anchor), and B (0.6, Magfit-IP-IDN dome type). After 28 days, the analyzed ion release increased irregularly: Fe (173.58, Magfit-IP-IDN dome type), Pd (44.17, Medical-anchor), Cr (2.02, Magfit-IP-IDN dome type), Ti (2.11, Magfit-IP-IDN abutment), Co (26.13, Medical-anchor), B (1.77, Magfit-IP-IDN dome type), and Nd (79.18, Magfit-IP-IDN dome type). In the group of magnetic systems on natural teeth, the highest ion release after 7 days was found for Fe (4.81, Magfit DX 800 keeper), Cr (1.18, Magfit DX 800 keeper), Pd (0.21, Direct System Keeper), Ni (0.18, WR-Magnet S3 small), Co (0.12, Direct System Keeper), and Ti (0.09, Magna Cap , Mini). After 28 days, the analyzed ion release increased non-uniformly: Fe (31.92, Magfit DX 800 Keeper), Cr (6.65, Magfit DX 800 Keeper), Pd (18.19, Direct System Keeper), Ni (0.61, WR-Magnet S3 small), Co (10.94, Direct System Keeper), Ti (0.83, Magna Cap , Mini), and Pd (2.78, EFM Alloy). In contrast, the uncased control magnet showed an exponential release after 7 days of Sm ions (55.06) and Co-ions (86.83), after 28 days of Sm ions (603.91) and Co ions (950.56). The release of corrosion products of all tested products stayed significantly under the limit of 200 ,g/cm2 (ISO 22674:2006). In contrast, the non-encapsulated control magnet exceeded that limit significantly. Conclusion: The analysis of the corrosion behavior of modern magnetic attachments for use on teeth and dental implants according to ISO 10271:2001 showed that metal ions had dissolved on all specimens. In the case of one product, the magnet corroded. For this product, an improvement of the capsulation would be desirable. None of the products reached the limit specified in ISO 22674:2006. All products seem to be suitable for dental application. Further studies in regard to the specific biocompatibility and possible cytotoxic effects on mucosa and tissue would be desirable. [source] Mechanical Properties of Magnetic Attachments for Removable Prostheses on Teeth and ImplantsJOURNAL OF PROSTHODONTICS, Issue 8 2008Arne F. Boeckler DMD Abstract Purpose: Magnetic attachments on teeth and implants may be used to improve stability, support, and retention of removable prostheses. Various forms of magnetic attachments are available, divided according to the design, the mechanical properties of the attachments, and the clinical indication. Recently developed attachment systems are small and promise improved retentive capacity, while existing magnetic attachments continue to be technologically modified and improved. This investigation reviewed and compared maximum retentive forces and characteristic curves for magnetic attachments indicated for use as root anchors and on implants. Materials and Methods: Twenty-four samarium-cobalt (SmCo) and neodym-iron-boron (NeFeB) magnetic attachments (12 tooth- and 12 implant-borne) were evaluated. Specimens were delivered by the manufacturers or fabricated according to their instructions. Five magnet pairs of each product and each combination were tested 10 times in a calibrated universal testing machine using a nonmagnetic test device (s = 40 mm, v = 20 mm/min). Results were recorded electronically and compared to manufacturers' details. Results: Maximum retentive forces for root keepers ranged from 1.4 to 6.6 N. Maximum retentive forces for magnetic attachments on implants ranged from 0.7 to 5.8 N. After a distance of 0.1 mm, a complete reversed distribution of the different systems became obvious. The retentive force provided by the manufacturer was achieved in one implant abutment, with retentive force (as compared to those provided by the manufacturers) for root keepers ranging between 42.5% and 92.9% and for implant abutments between 43.0% and 99.4%. Conclusion: There were differences between magnetic attachments for both the initial retentive capabilities and the characteristic curves. Recently introduced products provided relatively high initial retentive forces despite their small size. The measured retentive forces and the manufacturer's information differed in the majority of magnetic systems evaluated. [source] Computerized Color Formulation for African-Canadian People Requiring Facial Prostheses: A Pilot StudyJOURNAL OF PROSTHODONTICS, Issue 4 2008FETC, MIMPT, MPhil, T.J. Coward PhD Abstract Purpose: The aim of this study was to investigate the effectiveness of spectrophotometry and a computerized color formulation system to predict pigment formulas for color mixing silicone elastomer to match the skin color of African-Canadian people. Materials and Methods: In a prospective study, reflectance spectrophotometery was used to measure the skin color of 19 African-Canadian subjects. The spectral data for each subject was used in a computerized color formulation system to predict colorants required to mix silicone elastomer to match each subject's skin color. Delta-E values were recorded for each silicone sample in comparison to the subject's skin measurement. An analysis of variance was used to determine significance among variables, and a Tukey HSD post hoc test was used to assess paired comparisons. Results: Delta-E decreased with iterative mixes of colored silicone for each subject, and pigment loading increased with iterative mixes. Delta-E values for the third iterative mix (fourth and final sample) ranged between 1.49 and 8.82. Conclusion: Spectrophotometry and computerized color formulation provide a foundation in the color matching procedure for facial prostheses that offers objectivity to an otherwise subjective task. Through further study of spectrophotometry and computerized color formulation, and with the development of pigment databases appropriate for the African-Canadian population, it may be possible to establish a precise and repeatable color matching system that predicts required colorants and controls metamerism. [source] International Functional Electrical Stimulation Society (IFESS): the Development of Controlled Neural Prostheses for Functional RestorationNEUROMODULATION, Issue 1 2000Ross Davis MD [source] Penile Prostheses for the Treatment for Erectile DysfunctionTHE JOURNAL OF SEXUAL MEDICINE, Issue 6 2010FRCS (hon.), Steven K. Wilson MD No abstract is available for this article. [source] Titanium versus Nontitanium Prostheses in Ossiculoplasty,THE LARYNGOSCOPE, Issue 9 2008Charles S. Coffey MD Abstract Objectives/Hypothesis: To compare the hearing outcomes and complications observed using either titanium or nontitanium prostheses in a 7-year consecutive series of ossiculoplasties performed by a single surgeon. Study Design: Retrospective. Methods: A database of ossicular reconstruction surgeries was reviewed for preoperative and postoperative audiometric data including air and bone conduction thresholds at four frequencies and speech reception thresholds. Outcomes were evaluated at time points less than and greater than 6 months postoperatively. Baseline demographic and surgical characteristics and postoperative complications were also noted. Results: A total of 105 cases had sufficient audiometric data available for analysis, including 80 performed with titanium and 25 with nontitanium implants. Follow-up ranged from 1.2 to 74.2 months, with a mean of 14.9 months. Mean air-bone gap at initial follow-up was 21.7 dB in the nontitanium group and 15.4 dB in the titanium group; this difference was significant (P = .01). Postoperative air-bone gap of less than 20 dB at initial follow-up was achieved in 50.0% of nontitanium cases and 77.1% of titanium cases (P = .012). This difference in "success" rates persisted at longer follow-up but did not achieve statistical significance. Mean speech reception thresholds at <6 months was 29.7 dB in the nontitanium group and 22.6 dB in the titanium group (P = .049). Extrusion was observed with two nontitanium prostheses (8.0%) and three titanium prostheses (3.8%) (P > .05). Conclusions: Titanium ossicular prostheses provide hearing outcomes superior to those of nontitanium prostheses when evaluated within 6 months after ossiculoplasty. [source] Safety of Magnetic Resonance Imaging of Stapes Prostheses,THE LARYNGOSCOPE, Issue 3 2005Mark James Syms MD Abstract Objective: Assess the safety of performing magnetic resonance imaging (MRI) on patients with stapes prostheses. Study Design: Survey and animal model. Methods: A survey regarding implant usage, MRI procedures, and adverse outcomes after MRI in patients previously undergoing stapes procedures. Guinea pigs implanted with ferromagnetic 17 to 4 stainless steel, 316L nonferromagnetic stainless steel, titanium, and fluoroplastic stapes prostheses underwent a MRI in a 4.7 Tesla MR system. Results: Three adverse outcomes were reported on the clinical survey. One adverse event occurred during an MRI performed on a recalled ferromagnetic prosthesis. The other two adverse events were probably not secondary to MRI exposure. No damage or inflammation was observed in the region of the oval window or vestibule of implanted guinea pigs exposed to a 4.7 Tesla MR system. Conclusions: The combination of prior studies, the clinical survey, and the absence of histopathologic evidence of damage in the guinea pigs is compelling evidence that MRI for patients with stapes prostheses is safe. Implanting physicians should feel comfortable clearing a patient for a MRI in a 1.5 Tesla or 3.0 Tesla MRI. It is imperative for the physician to qualify the field strength when clearing a patient to undergo a MRI. [source] A Method to Intraoperatively Assess Stapes Prostheses for Magnetic Attraction,THE LARYNGOSCOPE, Issue 12 2003David W. White MD Abstract Objective To present a technique used to assess metallic otologic protheses for magnetic susceptibility during surgery. Study Design Description of a surgical technique. Methods A sterile handheld pacemaker magnet is used to evaluate the prothesis prior to implantation. The magnet is placed over the prosthesis and the prosthesis is placed directly on the magnet. Any evidence of magnetic attraction and the prosthesis is rejected prior to implantation. Results None of the prostheses screened showed any magnetic attraction. As a control, steel wire was cut into pieces with dimensions similar to prostheses. These sections of wire were readily attracted to the magnet. Conclusions Intraoperative screening of metallic prostheses for magnetic susceptibility is possible using a sterile handheld pacemaker magnet. [source] Coated Prostheses Are Associated With Prolonged Inflammation in Aortic Surgery: A Cost AnalysisARTIFICIAL ORGANS, Issue 3 2008Shunya Shindo Abstract:, This prospective study was conducted to compare inflammatory responses between patients receiving coated and uncoated vascular prostheses, and to examine their effect on length of stay and cost of patients undergoing abdominal aortic aneurysmectomy. Patients undergoing elective vascular reconstruction of an abdominal aortic aneurysm were assigned randomly to coated-graft or uncoated-graft groups (n = 20, for each group). Interleukin (IL)-6, granulocyte elastase, white blood cell count, C-reactive protein (CRP), and body temperature (BT) were prospectively recorded preoperatively and on postoperative days (PODs) 1, 3, 7, and 14. In-hospital stay and hospitalized costs were also analyzed. IL-6 and CRP concentrations in the coated-graft group were higher than those in the uncoated-graft group (P = 0.01 and 0.05). BT was more frequently elevated >37°C at POD 14 in the coated-graft group than in the uncoated-graft group (P =0.03). Discharge was delayed, and overall hospitalization cost was higher in the coated-graft group than in the uncoated group (17.6 vs. 13.5 days, and 2 010 000 vs. 1 780 000 yen, P = 0.006 and P = 0.002, respectively). Coated vascular prosthesis demonstrated more profound inflammatory reaction than noncoated prosthesis, postoperatively. [source] Study of the Different Types of Actuators and Mechanisms for Upper Limb ProsthesesARTIFICIAL ORGANS, Issue 6 2003Vanderlei O. Del Cura Abstract: Research in the area of actuators and mechanisms has shown steadily growing technological advances in externally activated upper limb prostheses. From among the actuators, advances include the use of piezoelectric materials, special metal alloys, polymers, and new motor applications, while the advances in mechanisms include mechanical designs based on the anatomy of the human hand and improvements in the way these components are combined. These efforts are aimed at meeting the need for anthropomorphic and functional prosthetic devices that enable patients to carry out basic daily tasks more easily and reduce the rejection rate of prostheses. This article technically discusses the several types of actuators and mechanisms, listing their main characteristics, applications, and advantages and disadvantages, and the current state of research in the area of rehabilitation of upper limb functions through the use of active prostheses. Comparisons of these devices are made with regard to the main criteria of construction and operation required to achieve optimal prosthetic performance. [source] Thrombolytic Therapy with Tissue Plasminogen Activator for the Treatment of Nonstructural Malfunction of Bileaflet Cardiac Valve ProsthesesARTIFICIAL ORGANS, Issue 5 2002Hideki Teshima Abstract: This study was conducted to determine the effect of thrombolytic therapy with tissue plasminogen activator (t-PA) for nonstructural malfunction of bileaflet cardiac valve prostheses. Twenty-seven patients with bileaflet prosthetic valve malfunction diagnosed by a combination of cineradiography and transthoracic echocardiography were treated with the administration of intravenous t-PA. The treatment resulted in complete success in 55.6% (15 of 27), partial success in 22.2% (6 of 27), and no change in 22.2% (6 of 27). In the complete success and partial success groups, the condition of the patients in 85.7% (18 of 21) of the cases improved within 24 h after the administration of t-PA. Six cases in whom thrombolytic therapy was instituted more than 1 month (ranged from 1 to 38 months, mean 14.7 months) after the diagnosis of prosthetic valve malfunction showed significantly less effectiveness of thrombolytic therapy with t-PA. Only one patient (3.7%) had a major complication (thromboembolism) after t-PA treatment. The results suggest that thrombolytic therapy with t-PA in patients with nonstructural malfunction of bileaflet cardiac valve prostheses is effective with low incidence of complication when the treatment is instituted early after the diagnosis. [source] Modeling Lipid Uptake in Expanded Polytetrafluoroethylene Vascular Prostheses and Its Effects on Mechanical PropertiesARTIFICIAL ORGANS, Issue 5 2000Diego Mantovani Abstract: The radial transport across the wall of expanded polytetrafluoroethylene (ePTFE) arterial prostheses has a significant effect on lipid uptake observed in prostheses implanted in humans, which has been postulated to be one of the causes associated with implant failure. The goal of this study was to stimulate radial transport on a lipidic dispersion across the wall of an ePTFE prosthesis and investigate its effects on the circumferential mechanical properties of the prosthesis. An in vitro model was developed to simulate the lipidic radial transport across the wall. Lipids contained in a phosphatidylcholine dispersion were used as the transported molecules. Lipid concentration profiles were obtained after exposing commercial ePTFE prostheses to various transmural pressure and/or lipidic concentration gradients. Phospholipids gradually accumulated up to the external reinforcing wrap of the prosthesis, which clearly acted as a rigid barrier against lipid infiltration. Tensile tests performed on the virgin samples showed that the wrap was much more rigid than the microporous part of the prosthesis. After the lipid simulation, the rigidity of the wrap decreased with respect to what was observed for the virgin prosthesis. Finally, some clinical implications of this phenomena are discussed. [source] Early Complete Failures of Fixed Implant-Supported Prostheses in the Edentulous Maxilla: A 3-Year Analysis of 17 Consecutive Cluster Failure PatientsCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2006Odont Dr/PhD, Torsten Jemt DDS ABSTRACT Background, Clusters of implant failures in the edentulous maxilla seem to occur in some patients. To create groups for analysis with higher numbers of these patients implies large original groups for inclusion. Purpose, The aim of this study was to retrospectively describe and compare a group of "cluster failure patients" with randomly selected patients treated in the edentulous maxilla. Materials and Methods, From a group of 1,267 consecutively treated patients in one clinic, all patients presenting failing fixed implant-supported prostheses within the first 3 years of follow-up were included. All patients were treated with turned titanium implants using two-stage surgery. A control group of equal number of patients were created for comparison. Data on patients were retrospectively retrieved from their records, and compared. Results, Seventeen patients (1.3%) met the inclusion criteria in the entire group. The bone resorption index revealed less bone quantity in the study group (p < .05) during implant placement, but there was no difference regarding primary implant stability at first-stage surgery. The distribution of short and long implants showed relatively higher number of short implants in the study group (p < .05), and more patients had a presurgical discussion on the risk of implant failure prior to treatment in this group (p < .05). Only 5 out of 102 implants (4.9%) were lost before prosthesis placement as compared to 38 and 25 lost implants during the following two years in the study group. Smoking habits and signs of bone loss related to periodontitis in the lower dentition were more frequent in the study group, but did not reach a significant level (p > .05). Conclusion, The results indicate that bone quantity, reflected in fixture length, has a significant impact on increased implant failure risk. Other factors of interest as predictors for implant failures could be smoking habits and also possibly signs of periodontitis in the opposing dentition. [source] Fixed Implant-Supported Prostheses in Elderly Patients: A 5-Year Retrospective Study of 133 Edentulous Patients Older than 79 YearsCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2004Ingela Engfors DDS ABSTRACT Background: An increasing number of elderly patients are treated with implants, but results for the elderly patient in terms of implant success and adaptation to implant prostheses are contradictory. Objective: To retrospectively study the 5-year clinical and radiologic performances of fixed implant-supported prostheses placed in edentulous elderly patients and to compare those results with the results of using similar prostheses in a control group of younger patients. Materials and Methods: The study group comprised 133 edentulous patients who were 80 or more years of age and who were consecutively treated with fixed implant-supported prostheses between January 1986 and August 1998. Altogether 761 Brånemark System® implants (Nobel Biocare AB, Göteborg, Sweden) were placed in 139 edentulous jaws. The control group comprised 115 edentulous patients who were younger than 80 years and who were treated consecutively from March 1996 to November 1997 with similar prostheses. In this group 670 implants were placed in 118 edentulous jaws. Information was collected from all postinsertion visits, including the fifth annual checkup, and changes of marginal bone levels were analyzed from intraoral radiographs. Results: The 5-year cumulative survival rate (CSR) for implants in the maxilla was 93.0% in the study group and 92.6% in the control group; the corresponding CSRs for implants in the mandible were 99.5% and 99.7%. The most common complications for patients in the study group were soft tissue inflammation (mucositis) and cheek and lip biting (p < .05) whereas resin veneer fractures were the most common complications for the control group. Overall 5-year marginal bone loss for the study group was 0.7 mm (standard deviation [SD], 0.45) in the upper jaw and 0.6 mm (SD, 0.50) in the lower jaw. Differences in bone levels and bone loss between the two groups did not reach significant levels (p > .05). Conclusions: Implant treatment in the elderly patients showed treatment results comparable to those observed in younger age groups. However, indications of more problems with adaptation could be observed and were reflected in more postinsertion problems. Cleaning problems and associated soft tissue inflammation (mucositis) as well as tongue, lip, and cheek biting were significantly more often observed among the elderly patients (p < .05). [source] A 5-Year Prospective Follow-Up Study of Implant-Supported Fixed Prostheses in Patients Subjected to Maxillary Sinus Floor Augmentation with an 80:20 Mixture of Bovine Hydroxyapatite and Autogenous BoneCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2004Mats Hallman DDS ABSTRACT Background: Prospective long-term follow-up studies evaluating the use of bone substitutes to enable dental implant placement and integration are rare. Purpose: This study was undertaken to evaluate the survival rate of dental implants placed 6 months after maxillary sinus floor augmentation using a mixture of 80% bovine hydroxyapatite (BH) and 20% autogenous bone (AB). Material and Methods: Twenty patients subjected to 30 maxillary sinus floor grafting procedures using fibrin glue and an 80:20 mixture of BH and AB to enable placement of dental implants 6 months later were followed for 5 years of functional loading. Clinical and radiographic examinations of the grafts and implants were performed. Results: After 5 years of functional loading with fixed bridges, 15 of 108 implants had been lost, giving a cumulative survival rate of 86%. The mean marginal bone loss after 5 years was 1.3 ± 1.1 mm. Conclusion: Grafting of the maxillary sinus with a mixture of BH and AB and later placements of turned implants could be performed with predictable long-term results. All but one of the patients who were observed had functional fixed bridges after 5 years of functional loading. [source] Implant-Supported Fixed Prostheses for the Rehabilitation of Periodontally Compromised Dentitions: A 3-Year Prospective Clinical StudyCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2001Odont(hc), Seung-Won Yi DDS ABSTRACT Background: The application of a strict hygiene maintenance care protocol following rehabilitation of periodontally compromised dentitions by means of tooth-supported fixed partial dentures has demonstrated excellent long-term treatment outcome. Purpose: A clinical and radiographic study was performed to document and evaluate the short- and medium-term result of occlusal rehabilitation by means of implant-supported fixed prostheses (ISFPs) in patients treated for advanced peri-odontal disease. Materials and Methods: Forty-three consecutive patients were included. All patients were referred because of advanced periodontal disease. Before the implant therapy was initiated, periodontal treatment was performed and the outcome evaluated during at least a 6-month period. An individual maintenance care program was designed for each patient. All 125 implants were placed using a two-stage surgical approach. Following installation of the ISFPs, all patients underwent a baseline examination including evaluation of oral hygiene, periodontal or peri-implant conditions, and radiographs. These examinations were repeated annually during the 3-year observation period. Results: No single implant was lost during the 3-year follow-up period. The percentages of plaque-harboring surfaces and bleeding units on probing were found to be low (< 10%), and no soft-tissue complications were recorded. The mean marginal bone resorption during the observation period amounted to 0.21 mm. In a few patients, apposition of marginal bone was observed. Bone loss amounting to 0.5 mm or less was found around 81% of the implants (101/125 implants). The amount of bone loss around the remaining 24 implants (19%) varied between 0.5 and 2.0 mm. Conclusions: The present clinical trial demonstrates that, at least during a 3-year period, the ISFP is an acceptable and predictable treatment option for rehabilitation in patients who have lost their teeth because of periodontal disease. This observation seems to be valid in edentulous and partially dentate jaws. A prerequisite to reach such a favorable treatment outcome is possibly the combination of the strict maintenance care program and the careful design of the ISFPs. [source] Delayed Presentation of Low Molecular Weight Heparin Treatment Failure in a Patient With Mitral Valve ProsthesisJOURNAL OF CARDIAC SURGERY, Issue 1 2007Sotiris C. Stamou M.D. The patient did not develop the embolic complication from the thrombosis until almost 4 months after the bridging sequence with low molecular weight heparin. The patient underwent thrombectomy of the mitral valve. At least 16 similar cases with mechanical valve prostheses and treatment failure of low molecular weight heparin have been reported. [source] Transvenous Cardioverter-Defibrillator Implantation in a Patient with Tricuspid Mechanical ProsthesisJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2007MAURO BIFFI M.D. Background. A 64-year-old woman was referred to our center because of poorly tolerated ventricular tachycardia (VT) at 210 bpm due to an old myocardial infarction. The patient had been operated on at age of 20 for mitral valve commissurolysis, at age of 49 for ductal carcinoma, at age of 56 for mitral valve replacement, and at age of 61 for tricuspid valve replacement. Left ventricular EF was 31%. The patient was in permanent atrial fibrillation (AF) since the age of 53. She had undergone three cardiac surgery procedures, ending with two prosthetic mechanical valves. The cardiac surgery team advised against an epicardial ICD implantation. Results. We achieved a fully transvenous implant, with a screw-in defibrillation coil in the low right atrium and a bipolar pacing/sensing lead in a posterolateral branch of the coronary sinus. Pacing/sensing parameters were reliable, and effective defibrillation occurred at 20 J by a stepdown protocol. During 16-month follow-up, three VT episodes at 210 bpm were terminated by antitachycardia pacing (ATP) therapy. Left ventricular pacing/sensing was stable at long term. Conclusion. Thanks to technologic improvements, transvenous ICD implantation is feasible and safe in patients with a tricuspid mechanical prosthesis. [source] Laser-Welded Hollow Pontic Full-Gold Fixed Dental ProsthesisJOURNAL OF PROSTHODONTICS, Issue 5 2010Alan J. Sutton DDS Abstract This article describes a technique for the fabrication of a laser-welded hollow pontic full-gold fixed dental prosthesis. Reference to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government. The opinions of the authors expressed herein do not necessarily state or reflect those of the U.S. Government, and shall not be used for advertising or product endorsement purposes. [source] Resin-Bonded Overcasting to Salvage a Long-Span Fixed Prosthesis: A Clinical ReportJOURNAL OF PROSTHODONTICS, Issue 5 2008Hiroshi Shimizu DDS Abstract To salvage a failing long-span fixed partial denture (FPD), a resin-bonded overcasting made of a silver-palladium-copper-gold alloy was fabricated and cemented using an adhesive metal conditioner and adhesive resin luting agent to an existing multiple-abutment FPD. [source] Nasal Prosthesis for Total Rhinectomy PatientJOURNAL OF PROSTHODONTICS, Issue 3 2000Sudarat Kiat-amnuay DDS [source] 3D Computerized Model for Measuring Strain and Displacement of the Brachial Plexus Following Placement of Reverse Shoulder ProsthesisTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2008Tom Van Hoof Abstract The aim of the present study was to develop a method for three-dimensional (3D) reconstruction of the brachial plexus to study its morphology and to calculate strain and displacement in relation to changed nerve position. The brachial plexus was finely dissected and injected with contrast medium and leaden markers were implanted into the nerves at predefined places. A reverse shoulder prosthesis was inserted in a cadaveric specimen what induced positional change in the upper limb nerves. Computed tomography (CT) was performed before and after this surgical intervention. The computer assisted image processing package Mimics® was used to reconstruct the pre- and postoperative brachial plexus in 3D. The results show that the current interactive model is a realistic and detailed representation of the specimen used, which allows 3D study of the brachial plexus in different configurations. The model estimated strains up to 15.3% and 19.3% for the lateral and the medial root of the median nerve as a consequence of placing a reverse shoulder prosthesis. Furthermore, the model succeeded in calculating the displacement of the brachial plexus by tracking each implanted lead marker. The presented brachial plexus 3D model currently can be used in vitro for cadaver biomechanical analyses of nerve movement to improve diagnosis and treatment of peripheral neuropathies. The model can also be applied to study the exact location of the plexus in unusual upper limb positions like during axillary radiation therapy and it is a potential tool to optimize the approaches of brachial plexus anesthetic blocks. Anat Rec, 291:1173-1185, 2008. © 2008 Wiley-Liss, Inc. [source] Shape-Memory Stapes Prosthesis for Otosclerosis SurgeryTHE LARYNGOSCOPE, Issue 8 2005Glenn W. Knox MD Abstract Objectives: The aim of this study was to determine the efficacy of a shape-memory alloy, Nitinol, as a component of an improved stapes prosthesis. Study Design: Prospective laboratory and clinical study to develop a Nitinol stapes prosthesis. Methods: Various diameters of Nitinol wire and temperature transition variants were analyzed with regard to ease of deformation, response to heating, and strength. The size and geometry of the closed hook was determined by measurement of 50 incus cadaver bones. Several heat sources for activating the shape memory were evaluated, including electrocautery, lasers, and warm water. Trial surgeries were then performed on human temporal bones in the laboratory. The closure characteristics of the Nitinol loop were studied. Magnetic resonance imaging (MRI) testing at 1.5 Tesla was performed to determine safety during MRI studies. Preliminary human subject trials were then instituted. Results: In all cases, a low heat condition was ample to activate the shape memory characteristics of the hook and return it to a closed position after it had been opened. Laser power was generally set well below the power needed for removing bone. The Nitinol loop closed snugly around the incus with application to the top of the hook with a low temperature laser setting. Almost any heat source was effective. MRI testing at 1.5 Tesla showed no movement of the prosthesis. Preliminary results in human subjects showed excellent air-bone closure. The Nitinol loop holds uniform contact around the incus. Conclusions: The Nitinol piston greatly simplifies the stapedectomy procedure by taking the need for a hand operated instrument out of the surgeon's hands. Because of the nature of the Nitinol wire, it can never over-crimp. All these characteristics make the prosthesis advantageous for otosclerosis surgery. [source] Implantable Imaging System for Visual ProsthesisARTIFICIAL ORGANS, Issue 6 2010Chuanqing Zhou Abstract In order to propose a method of intraocular imaging system for the visual prosthesis, an implantable microcamera was developed and evaluated in vivo. The microcamera was specially developed and shaped to fit the rabbit's lens capsule and encapsulated with the biocompatible silicone. To evaluate the feasibility of this novel approach, the custom-built device was implanted following the surgical extraction of rabbit's lens. And clinical examinations were performed 1 day, 3 days, 1 week, 2 week, and 1 month postoperatively, including slit-lamp examination, intraocular pressure, wound status, anterior chamber depth, the presence of the iris fibrosi of neovascularization, and the position of the implant. Real-time imaging was performed in vivo 1 month after the operation, and the acquired images were processed with the software and hardware that were specially developed for generating the stimulating pulses. Short-term results showed the novel approach is promising. [source] Measuring Quality of Life in Stroke Subjects Receiving an Implanted Neural Prosthesis for Drop FootARTIFICIAL ORGANS, Issue 5 2010Anke I. Kottink Abstract The aim was to determine if the treatment of a drop foot by means of an implantable two-channel peroneal nerve stimulator improves health-related quality of life (HRQoL). All subjects were measured at baseline and after a follow-up period of 12 and 26 weeks. Twenty-nine stroke survivors with chronic hemiplegia with drop foot who fulfilled the predefined inclusion and exclusion criteria were included in the present randomized controlled trial. The intervention group received an implantable two-channel peroneal nerve stimulator for correction of their drop foot. The control group continued using their conventional walking device, consisting of an ankle-foot orthosis, orthopedic shoes, or no device. HRQoL was assessed in two different ways: (i) by taking descriptive measures, that is, the Short Form-36 (SF-36; generic measure) and the Disability Impact Profile (DIP; specific measure); and (ii) by obtaining preference-based utilities both measured with the time trade-off (direct way) and by calculating them from the EuroQol (EQ-5D) and SF-36. A significant positive effect of the implantable device was found on the physical functioning domain, the general health domain, and the physical component summary score of the SF-36. For the DIP, a significant improvement was found on the domains mobility, self-care, and psychological status in the intervention group. Regarding the preference-based utility measures, a significant effect was found for the utility index calculated from the EQ-5D. The implantable two-channel peroneal nerve stimulator seems to be efficient to improve HRQoL, mainly the domains related to physical functioning. A relation was present between the utility indexes calculated from the EQ-5D and SF-36. [source] Long-Term Survivors After Valve Replacement With a Starr-Edwards Mitral Disk Valve ProsthesisARTIFICIAL ORGANS, Issue 6 2006Shigeaki Aoyagi Abstract:, We report four long-term survivors after valve replacement with a Starr-Edwards (S-E) mitral caged-disk valve. A model 6520 disk valve, size 3M, had been used in all of the four patients. Of the four patients, three underwent replacement of the disk valves 23, 24, and 26 years after mitral valve replacement (MVR), respectively. A pacemaker was implanted in the remaining patient 33 years after MVR. The S-E disk valves were considered hemodynamically slightly stenotic compared with modern bileaflet valves. No disk wear was detected in any of the three explanted valves, and in the remaining patient, a noninvasive evaluation of the disk showed that it was functioning normally. These results suggest the favorable long-term durability of the S-E disk valve. [source] Guided Surgery and Presurgical Prosthesis: Preliminary Results of 33 Fully Edentulous Maxillae Treated in Accordance with the NobelGuide® ProtocolCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2010Luc Gillot DDS ABSTRACT Objective: The aim of this study was to present the preliminary results of 33 edentulous maxillary patients treated using the Nobelguide® (Nobel Biocare AB, Göteborg, Sweden) technique. Materials and Methods: Thirty-three patients were treated according to the conventional protocol of the Nobelguide® technique in two clinical centers. This group of patients received 211 implants. Monitoring was carried out for over 12,51 months, depending on the patient. The Nobelguide® protocol was used for all patients. Results: Of the 211 implants loaded, four were lost (1.9%). The implant survival rate was therefore 98.1%. The prosthetic survival rate was 100%. There were some per-operative complications (four) and some postoperative complications (10 fractures of resin). Conclusion: These preliminary results seemed rather promising. These were the first cases of experienced surgeons who needed to learn a new implant placement protocol. It was clear that analysis and understanding of the system were essential in order to obtain such a success. Only one implant was replaced without there being any impact on the prosthesis survival rate which is 100%. [source] Malignant Tumors of the Maxilla: Virtual Planning and Real-Time Rehabilitation with Custom-Made R-zygoma Fixtures and Carbon,Graphite Fiber-Reinforced Polymer ProsthesisCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 1 2008Karl Ekstrand LDS ABSTRACT Background: Oral cancer is a mutilating disease. Because of the expanding application of computer technology in medicine, new methods are constantly evolving. This project leads into a new technology in maxillofacial reconstructive therapy using a redesigned zygoma fixture. Purpose: Previous development experiences showed that the procedure was time-consuming and painful for the patients. Frequent episodes of sedation or general anesthetics were required and the rehabilitation is costly. The aim of our new treatment goal was to allow the patients to wake up after tumor surgery with a functional rehabilitation in place. Materials and Methods: Stereolithographic models were introduced to produce a model from the three-dimensional computed tomography (CT). A guide with the proposed resection was fabricated, and the real-time maxillectomy was performed. From the postoperative CT, a second stereolithographic model was manufactured and in addition, a stent for the optimal position of the implants. Customized zygoma implants were installed (R-zygoma, Integration AB, Göteborg, Sweden). A fixed construction was fabricated by using a new material based on poly(methylacrylate) reinforced with carbon/graphite fibers and attached to the implants. On the same master cast, a separate obturator was fabricated in permanent soft silicon. Results: The result of this project showed that it was possible to create a virtual plan preoperatively to apply during surgery in order for the patient to wake up functionally rehabilitated. Conclusion: From a quality-of-life perspective, it is an advantage to be rehabilitated fast. By using new computer technology, pain and discomfort are less and the total rehabilitation is faster, which in turn reduces days in hospital and thereby total costs. [source] Hypersensitivity reactions associated with endovascular devicesCONTACT DERMATITIS, Issue 1 2008Golara Honari Allergic reactions to endoprostheses are uncommon and reported in association with orthopaedic, dental, endovascular and other implanted devices. Hypersensitivity reactions to the biomaterials used in endovascular prostheses are among the infrequent reactions that may lead to local or systemic complications following cardiovascular therapeutic interventions. This article reviews potential immunotoxic effects of commonly used biomaterials. Reports of putative hypersensitivity reactions to endovascular devices, including coronary stents, perforated foramen occluders, pacemakers and implantable cardioverter defibrillators are also reviewed. [source] | |||||||||||||||||||||||||||||||||||||||||||