Simulation Analysis of Stress Corrosion and Passivation Behavior on Micro-Defects of Dental Bone Implants

This study constructed a coupled mechanical-electrochemical finite element model of Ti-6Al-4V dental implants considering surface micro-defects, and systematically analyzed the corrosion evolution under the combined effects of oral load and body fluid environment. The results show that preloading leads to stress concentration at the center of micro-defects, with the edges acting as anodes and preferentially dissolving, forming lateral corrosion propagation. A strong passivation film significantly inhibits the anodic reaction and reduces stress release efficiency. Oxygen concentration regulates passivation film formation, and a low-oxygen environment helps slow the overall corrosion rate. The model effectively reveals the corrosion mechanism of implants under complex environments, providing a theoretical tool for implant life prediction.