| Summary: | 碩士 === 國立陽明大學 === 牙醫學系 === 105 === Motivation: The mechanism of early implant bone loss is not fully understood. It is still a controversial issue about which implant crest module geometry is more favorable for the preservation of crestal cortical bone.
Purpose: The main purpose of this study is to compare the stress at crestal cortical bone of three different implant crest module designs: divergent, straight & convergent.
Materials and methods: Models set up of divergent, straight, and convergent implant crest module with implant body, prostheses and region of posterior left mandible. To stimulate osseointegration, the models were designed as ”bonded” between implant and alveolar bone. Under vertical loading, 200N was applied over five occlusal contacts to stimulate maximum intercuspal position. Under oblique loading, 200N was applied at two occlusal contacts over buccal cusps at 30-degree with the direction from buccal to lingual. The stress distribution in the peri-implant bone and the displacement of implant were analyzed.
Results: The peak von Mises stress concentrated around the crestal region of cortical bone and the bottom of cortical bone, especially in the group of convergent group. The maximal von Mises stress of divergent, straight, and convergent models were 41.4 MPa, 54.3 MPa, and 62.4 MPa during vertical loading and 88 MPa, 90.6 MPa, and 112.6 MPa during oblique loading.
Conclusion: Within the limitation of this study, convergent implant crest module model could induce more stress concentrated around cortical bone and implant crest module area, especially in oblique loading condition. The shape of implant crest module may play an important role in stress distribution around bone.
Key word: early implant bone loss, implant crest module, stress distribution, finite element analysis
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