Effect of taper fit at the dental implant–abutment interface on mechanical performance: In vitro study

PURPOSE: The purpose of this study is to analyze the impact of changes in the implant-abutment interface fit taper on loosening and fatigue performance. MATERIALS AND METHODS: Three abutment structures with varying tapers (11.5°, 12°, and 13°) were self-designed and customized. Then, the impact of different taper fits between the abutment and implant on loosening and fatigue performance was investigated. The experiments measured screw preload, static and dynamic loosening torque, abutment settlement, pullout force, and the fatigue life of the implant system. The surface wear of the abutment and fatigue fracture surfaces were analyzed, and the experimental results were validated through finite element analysis (FEA). RESULTS: The abutment and implant have the same 11.5° matching taper increased preload, loosening torque, pullout force, and fatigue life. The fracture of the implant system occurs at the simulated bone plane, and the FEA of the stress concentration area aligns with the fatigue fracture results. CONCLUSIONS: Adopting a consistent 11.5° taper design at the abutment-implant interface could enhance the anti-loosening effect and extend the fatigue life, but a higher abutment pullout force may increase the difficulty of clinical restoration. Therefore, when the connection cone angle of the implant is 11.5°, using a 12° conical abutment may achieve optimal application results.