不同长度微种植体支抗应力差异的三维有限元研究

Research on 3-D FEM stresses around anchorage micro-implants with different length

目的 分析不同长度微型种植体在承载不同方向4 0 0g正畸力时的应力分布和大小。方法 利用三维有限元软件ANSYS建立不同长度的微型支抗种植体-骨有限元非线性分析模型,在加载侧方力(与种植体长轴成4 5°和90°)的条件下进行分析计算。结果 ①在两种加载条件下,不同长度的微型种植体应力值(包括单元应力和节点应力)呈规则分布,均显示8mm长度时,应力值最小,并且随着微种植体长度的增加或减小,应力值都呈增加趋势;②种植体颈部为应力集中区。结论 在承受非轴向力的作用下,8mm微种植体颈部的应力值最低,并且随微种植体长度的变化,应力都呈上升趋势。

Objective To investigate the stress around anchorage micro-implants with different length and select the appropriate micro-implant for orthodontic anchorage. Methods Three-dimensional element method (FEM) was used to analyze the stress around micro-implant with different length (5mm, 6mm, 7mm, 8mm, 9mm, 10mm), which was 400 grams loaded.The direction of the load was horizontal and 45 degree referring to the axis of micro-implant. Results ①The 8 mm micro-implant had mini-stress distribution and then the stress increased when the length of micro-implant changed;② the neck of micro-implant and the cortical bone were stress-focused areas. Conclusion The length can influence the stress around micro-implant. If possible, one should choose 8mm micro-implant or shorter.