Long-Term Clinical Outcomes of Different Types of Implant- Supported Prostheses: A Retrospective Study

The aim of this retrospective study was to evaluate the long-term clinical outcomes of implant-supported prostheses and to analyze the type, frequency, and distribution of prosthetic complications in relation to prosthesis-related factors.

Clinical records of patients who received implant-supported prosthetic treatment between 2017 and 2024 at the Department of Prosthodontics, Faculty of Dentistry, Gazi University, were retrospectively reviewed. A total of 269 patients with 778 implants were included. The follow-up period ranged from 14 to 228 months after functional loading, with a mean follow-up duration of 54.6 months. Fixed, hybrid, and implant-supported overdentures were evaluated. Prostheses were classified according to prosthesis type, restorative material, retention type, and impression level. Prosthetic complications were recorded. Statistical analyses included chi-square tests to evaluate complication distributions and Cox proportional hazards regression analysis to identify factors associated with time to first prosthetic complication. Statistical significance was set at P < 0.05.

Implant-supported prostheses showed favorable long-term clinical outcomes; however, biological, mechanical, and technical complications were observed. The most common complications were screw loosening, prosthetic fractures and chipping of the veneering material. Complication rates differed significantly according to restorative material, prosthesis type, retention type, and impression level. Fixed partial dentures showed higher rates of chipping and screw-related complications compared with implant-supported single crowns. Hybrid prostheses, particularly acrylic-based prostheses, showed a higher incidence of acrylic tooth fractures. Cement-retained prostheses were more frequently associated with peri-implantitis, whereas screw-retained prostheses showed higher rates of mechanical complications. Cox regression analysis demonstrated that prosthesis type, restorative material, impression level, and retention type significantly influenced the risk of prosthetic complications (P < 0.05).

Implant-supported prostheses exhibited high long-term survival in the present study; nevertheless, prosthetic complications were observed throughout the follow-up period. Prosthesis type, restorative material, retention type, and impression level were significantly associated with prosthetic complications. Appropriate treatment planning, material selection, regular follow-up, and patient compliance are essential to improve long-term clinical outcomes.