下颌桩核基牙式全口覆盖义齿基牙牙本质的应力分析

Stress analysis of abutment dentin of mandibular complete overdenture based on post-core abutment

目的 :研究下颌桩核基牙式全口覆盖义齿基牙牙本质的应力分布状况 ,为临床工作提供实验依据和理论基础。方法 :应用三维有限元应力分析法研究下颌桩核基牙式全口覆盖义齿基牙牙本质的应力分布特点 ,计算其应力值并与自然基牙作对比分析。结果 :在相同载荷条件下 ,两种形式基牙在牙本质根尖部均出现应力集中现象。桩的存在可改变应力的范围和大小 ,使颈部拉应力范围变小、数值增大 ,根尖部的应力集中现象稍有减小。结论 :桩核式基牙核的制作形态及自然基牙的制备形态符合牙合力的轴向传导方式。桩除固位作用外还有力的传导、应力中断及缓冲作用。桩核可以改变基牙牙本质原有的应力传导方式 。

objective: To study the stress distribution of abutment dentin of mandibular complete overdenture based on post core abutment(COBPA). Methods: 3 D FEM was employed to investigate the stress distribution of abutment dentin of mandibular COBPA and natural abutment(NA) on standard model, the data were compared. Results: In the same loading condition, stress concentration was observed at the root end area of dentin in both COBPA and NA. When post core was applied decreased stress distribution area and increased stress value were found aroud tooth neck, decreased stress concentration was found at root end. Conclusion: In COBPA and NA the stress may be transferred to the root end along the axis. Apart from retention, post core can transfer and buffer the stress, change the way of stress transfer, and may result in cervical fracture.