There was a statistically significant difference between the Ni-Cr control subgroup and the other two bleached subgroups, while there was no difference between the two bleached subgroups. Results also showed that increasing the concentration of bleaching agents increased the surface roughness of all the tested alloys. There was a statistical difference between the Ni-Cr alloy and the other two alloys in all tested subgroups except the in-office http://www.selleckchem.com/products/azd9291.html bleached subgroup, for which no difference between the surface roughness of the Ni-Cr alloy and the Co-Cr-Ti alloy was found. Scanning electron

microscopic examination revealed surface deteriorations in the two bleached subgroups for all tested ceramometallic alloys. Conclusion: Surface topographic alterations occurred as a result of the application of bleaching agents. These alterations increased with the increase of the carbamide peroxide concentration. “
“Purpose: This study evaluated the effects of different bar materials on stress distribution in an overdenture-retaining bar system with a vertical misfit between implant and bar framework. Materials and Methods: A three-dimentional finite element model was created including two titanium implants and a bar framework placed in the anterior part of a severely reabsorbed jaw. The model set was exported to mechanical simulation software, where displacement was applied to simulate the screw torque limited by 100-μm vertical misfit. Four bar materials

(gold alloy, silver-palladium FK866 cost alloy, commercially pure titanium, cobalt-chromium alloy) were simulated in the analysis. Data were qualitatively evaluated using Von Mises stress given by the software. Results: The models showed stress concentration in cortical bone corresponding to the cervical part of the implant, and in cancellous bone corresponding to the apical part of the implant; however, in these regions few changes were observed in the levels of stress on the different bar materials analyzed. In the bar framework, screw, and implant, considerable increase in stress was observed when the elastic modulus of the bar material was increased. Conclusions: The different materials

of the overdenture-retaining bar did not present considerable influence on the stress levels in the periimplant bone tissue, while the mechanical components of the system were more sensitive to the material 上海皓元医药股份有限公司 stiffness. “
“Purpose: This study assessed masticatory efficiency and duration of the masticatory cycle in 14 asymptomatic patients with severe bone resorption. All patients had worn complete dentures for over 10 years. Recall visits were scheduled at 5 months and 1 year after receiving new dentures. Materials and Methods: Fourteen patients were evaluated in this study. The Research Diagnostic Criteria questionnaire and tests of the efficiency and duration of the masticatory cycle were performed with artificial food before, 5 months after, and 1 year after new dentures were delivered.