不同牙尖斜度对单个种植义齿应力分布的影响

The influence of different inclination of cusp on the stress of an implant supported denture

目的 :分析不同牙尖斜度对种植义齿特别是基桩应力分布的影响。方法 :对下颌骨标本扫描 ,应用ANSYS建立模型并加载分析不同牙尖斜度下种植义齿的应力分布状态。结果 :非中心线负载下 ,基桩最大等效应力 (σi)位于第一个螺纹处 ,中心线负载下 ,基桩σi 位于基桩颈部 ;各种负载下 ,种植体与颌骨的σi 都位于种植体颈部与颈部周围骨皮质处 ,且向根尖逐渐减少 ;高牙尖斜度与非中心线负载可引起高应力集中。结论 :基桩应力集中区与临床上基桩易折断处相吻合 ;低牙尖斜度、平尖牙有利于种植义齿应力分布。

Objective: To analyze the influence of different inclination of cusp on the stress of an implant supported denture. Methods: A spiral CT was used to scan a corpus' head.The model of mandible,teeth and implant was established by ANSYS 6.1 software. The superstructure of the denture had three different inclination of cusp.The stress distribution of the models under loading was analyzed. Results: When bearing non central loading, the maximum equivalent stress (max EQV) of the abutment was situated at the first screw of the abutment.When bearing central loading, the maximum equivalent stress(max EQV) of the abutment was situated at the cervix. Under all loading, the max EQV of the implant was situated at the cervix, the max EQV of mandible was situated at the upper cortical layer around the cervix of the implant. Higher inclination of cusp and non central loading lead to higher stress. Conclusion: The location of the max EQV of the abutment is consistent with the location of the abutment fracture; lower inclination of cusp and flatsurface teeth are benefit to the stress distribution of the implantation.