Investigation of the effects of mechanical and thermal aging processes of various connection systems used in implant assisted motivated prostheses

Aim: This study was conducted to investigate the effects of mechanically aging and thermal cycling on the retention of various retention systems of implant supported overdenture prostheses. Material and Method: The model used in the study was obtained by pouring the fluidized polyurethane resin prepared in accordance with the instructions of the silicone mold manufacturer company which simulates the toothless bottom jaw. The four 11-mm-deep slots were arranged 11 mm apart from each other (center to center), parallel to each other. Overdenture prostheses were prepared by applying different types of holders (distal extension bar connection system, locator connection system, spherical connection system and TC-Snap connection system) on the same size and feature implants placed in the anterior region. Tensile forces were applied to the prepared specimens from four predetermined points (A, B, C, D) and double sided (A-B, B-C, C-D) and retention values of different types of holders were examined. Results: The study found statistically significant difference between retention loss of implant-supported overdenture prostheses after mechanical aging at 6 and 12 months SigmaPlot program was used for all statistical analyzes for the data. The distributions of the data sets were performed with the Shapiro-Wilk Normality test and the α = 0.05 level was considered significant. Results: The study found statistically significant difference between retention loss of implant-supported overdenture prostheses after mechanical aging at 6 and 12 months and after thermal cycling between 5000 and 10000 cycles with control group (p <0.05). The highest retention value was observed in the control group (86.45 N) with the distal extension bar connection system and the lowest retention value after 12 months mechanical aging (22.24 N) with the TC-Snap connection system (p <0.05). Conclusion: In the study, it was observed that the bar-supported overdenture prosthesis with the distal extension had the highest retention values, the retention values of 12 months and 10000 thermal cycling holders had the lowest retentive values. Key Words: Dental Implant, Overdenture Prosthesis, Thermal Cycle, Mechanical Aging, Attachment System