Clinical and Finite Element Evaluation of Fixed Implant Prosthesis Designs for the Edentulous Mandible

Objective This study aimed to evaluate the longitudinal clinical outcomes and biomechanical characteristics of various mandibular fixed implant‐supported prostheses, focusing on cantilever presence, implant quantity, bone density, and framework materials. Methods A retrospective clinical analysis and finite element analysis (FEA) were synthesized. The clinical cohorts of 17 patients were grouped by prosthetic design (cantilever versus non‐cantilever) to assess cumulative survival rates (CSR), marginal bone loss (MBL), technical complication rates, and bone density loss (BDL) over a 3‐year follow‐up period. Concurrently, 32 models were simulated for four configurations: All‐on‐4 with or without cantilevers (C4/A4) and All‐on‐6 with or without cantilevers (C6/A6). Occlusal loading was simulated across varying bone densities and framework materials. The peri‐implant stress and strain were evaluated. Results Both clinical cohorts showed high 3‐year implant CSR. However, cantilever group exhibited significantly higher MBL, whereas the between‐group difference in BDL varied over time. FEA suggested that distal cantilevers amplified peri‐implant stress and strain. In cases of posterior bone deficiency, the C6 design yielded more favorable biomechanical performance than the A4 configuration. While Type I bone reduced strain in FEA, no significant association was detected between clinical bone type and either MBL or BDL. Zirconia framework more effectively minimized peri‐implant stress and strain than polymethyl methacrylate. Conclusions While both prosthetic designs yield acceptable short‐term survival rates, cantilever configurations showed higher simulated implant stress and peri‐implant bone strain, consistent with the greater MBL observed in the clinical cantilever group. In cases of posterior bone deficiency, a six‐implant design with a short cantilever may distribute stress more effectively than utilizing a highly tilted four‐implant configuration.