Comparison of peri-implant bone stress with different implant crest module designed by 3D finite element analysis

Hsin-Mei Hsieh ； Ming-Lun Hsu

《Journal of Prosthodontics and Implantology》 7卷4期 (2018/12) Pp. 32-39

https://doi.org/10.6926/JPI.201812_7(4).0005

摘要

Purpose: The mechanism of early implant bone loss is not fully understood, and there is ongoing controversy regarding which implant crest module geometry is more favorable for the preservation of crestal cortical bone. The main purpose of this study was to compare the stress placed on crestal cortical bone by three different types of implant crest module designs: divergent, straight, and convergent designs. Material and methods: Models of divergent, straight, and convergent implant crest modules including an implant body, prostheses, and portion of the posterior left mandible were fabricated. To simulate osseointegration, the models were designed as if ＂bonding＂ had occurred between the implant and alveolar bone. A vertical loading of 200 N was applied over five occlusal contacts to simulate the maximum intercuspal position. An oblique loading of 200 N was applied at two occlusal contacts over the buccal cusps at a 30-degree angle with the direction of buccal to lingual. The stress distribution in the peri-implant bone and the displacement of the implant were then analyzed. Results: The peak von Mises stress was concentrated around the crestal region of the cortical bone and the bottom of the cortical bone, especially in the convergent model. The maximal von Mises stress values of the divergent, straight, and convergent models were 41.4 MPa, 54.3 MPa, and 62.4 MPa, respectively, during vertical loading and 88 MPa, 90.6 MPa, and 112.6 MPa, respectively, during oblique loading. Conclusion: Under the limitations of this study, the convergent implant crest module model induced more stress concentrated around the cortical bone and implant crest module area, especially in the oblique loading condition. The shape of an implant crest module may thus play an important role in the stress distribution around bone.

關鍵字

early implant bone loss ； implant crest module ； stress distribution ； finite element analysis