Abstract: Objective: To compare the effects of implant shape and implant angle on the stress of implant components and surrounding bone under different bone conditions by three-dimensional finite element analysis (FEA). Methods: The geometric models of cylindrical and tapered implants were established by using relevant software. The implants were implanted into class Ⅱ and class Ⅲ jaw models at the angles of 0°, 10°, 20°, and 30° respectively, and the two-stage individualized abutment with corresponding angles was used for restoration. The models were loaded by simulating three stress states. The peak stress and stress distribution were observed. Results: The stress of each component of the denture and the surrounding bone increased with the increasing of implant angle. Under the same load condition, the peak stress around the implant in class Ⅱ bone was significantly smaller than that in class Ⅲ bone. The peak stress in the columnar implant group was smaller than that in the tapered implant group, while that in the surrounding bone and the upper Ti-base stress was relatively larger. Conclusion: The direction of the implant had better be aligned with the axis of natural tooth to reduce the adverse effects of lateral force. Class Ⅱ bone was more conducive to disperse the stress than class Ⅲ bone. The tapered implant was beneficial to disperse the stress and help to protect the surrounding bone tissue, however, it was more prone to mechanical complications than the cylindrical implant.

Key words: finite element analysis, implant, individualized abutment, type of jaw bone