目的 分析支抗微种植体骨内段直径变化对颌骨应力分布和微种植体位移的影响,为临床选择微种植体和种植体优化设计提供理论参照.方法 利用Pro/E软件建立不同骨内段直径的微种植体和下颌骨三维有限元模型,并用Hypermesh对所建立模型进行网格划分,用ANSYS软件进行模拟计算,在种植体顶部中央位置施加1.96 N与颌骨面平行的作用力,分析在上述载荷作用下种植体的位移和骨界面应力的变化.结果 随着种植体骨内段直径的增加,骨界面应力峰值和微种植体位移都减小,应力峰值主要集中在颈部和尖部.骨内段直径为1.5mm时,微种植体z轴的Von-mises应力值最小,且曲线最为平缓.颌骨表面应力峰值的面积关系为1.7 mm＞1.6mm＞1.4 mm＞1.5 mm.结论 支抗微种植体骨内段直径对微种植体应力分布有影响,在本实验条件下,微种植体骨内段为1.5 mm时应力分布对颌骨损伤最小,微种植体位移最小.%Objective To analyze the stress distribution at micro-implant-bone interface and the displacement of micro -implant based on different endosteal section diameters for choosing orthodontic anchorage micro -implant and optimize design of micro-implant. Methods The finite element models of micro-implant with different endosteal section diameters and mandible were established by Pro/E software. The elements were divided by Hypermesh and the results were calculated by Ansys10.0. A force of 1.96 N was applied on the top of the implant parallel to the mandible surface to analyze the differences of the micro-implant displacement and that of the force on the micro-implant-bone interface. Results With the increasing diameter of endosteal section, both the maximum Von-mises stress on micro-implant-bone interface and the maximum displacement in micro-implant decreased. The maximum Von-mises stress focused on the neck and the tip of micro-implant. The Von-mises stress of micro-implant on z axis was the smallest, and the stress curved was the flattest at the endosteal section diameter of 1.5 mm than that of other sizes. The tendence of the contour map area for mandible surface stress was 1.7 mm>1.6 mm>1.4 mm>1.5 mm. Conclusion The influence of the micro-implant diameter in-bone on the micro-implant is significant. The damage on the mandible and the displacement of the micro-implant are both the smallest in the 1.5 mm case.
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