ABSTRACT
Objective To analyze the effect of different bone defect types on stress distributions of the implant- bone interface and bone-Bio-oss interface under dynamic loads by finite element method. Methods The finite element models for four types of bone defects (fenestrative bone defect, dehiscent bone defect, circular bone defect, vertical bone defect) without the first molars were established, then the models of grafting bone and implants corresponding to each model were established. The vertical load of 100 N and Oblique load of 200 N were used to simulate the dynamic chewing process of 5 stages in a masticatory cycle, and the maximum Von Mises stresses at the implant-bone interface and bone-Bio-oss interface were analyzed. Results In a masticatory cycle, from stage 2 to stage 4, the stresses on implant-bone interface increased by 81.6%, 90.7%, 182%, 106%, respectively, while the stresses on Bio-oss bone and natural bone interface increased by 26%, 13%, 6%, 56.25%, respectively. Conclusions The sequence of bone graft stability for the models with four types of bone defects is: circular bone defect> dehiscent bone defect>fenestrative bone defect>vertical bone defects. In clinic, doctors should screen the high-risk patients according to the sites of the bone grafts, and choose different methods for fixing the bone grafts so as to improve the stability of bone grafting. The axial loading will be more beneficial to the stress distributions on the interface, and the oblique loading should be decreased or avoided in clinical design for the superstructure of implant denture.