种植体不同植入角度及不同骨皮质厚度对其稳定性影响的三维有限元分析

Impacts of different implantation angles and thickness of cortical bone on stablitity of implants by three-dimensional finite element analysis

目的：以三维有限元法分析种植体支抗在不同植入角度及不同骨皮质厚度变化下其应力、位移变化的规律。方法：建立骨松质、种植体支抗及不同厚度骨皮质（1~8mm）的三维有限元模型,在种植体颈部加载200g正畸力,加力方向与颌骨骨面平行。采集应力、应变数据并进行分析。结果：①在40组工况中,各组Von Mises等效应力最大值在35.9~12.6MPa之间;角度对应力的影响是30°＆gt;45°＆gt;90°＆gt;60°或75°。②以30°植入1mm骨皮质时位移最大,并且应力、位移都随骨皮质厚度的增加而呈下降趋势。结论：①种植体支抗选择60°至75°左右的角度进行植入更好。②骨皮质厚度增加会提高种植体支抗植入的稳定性。③在骨皮质厚度大于1mm的情况下,不同的植入角度下加载200g的正畸牵引力所引起的Von Mises等效应力都在安全的范围内,不会引起骨吸收等问题。

Objective： To analyze the variation of stress and displacement of implant anchorage under different implantation angles and thichness of cortical bone by three-dimensional finite element method,to provide scientific basis for clinical implantation of implant anchorage.Methods： Three-dimensional finite element model of cancellous bone,implant anchorage and cortical bone with different thickness（1~8mm） was established.An orthodontic force of 200g paralleled to the surface of jawbone was applied to the neck of implant.The stress and strain data of each group were collected and analyzed.Results： ①Among 40 groups,the maximum value range of Von Mises equivalent stress of each group was from 35.9MPa to 12.6MPa;the impact degree of implantation angle on stress was ： 30°45°90°60°or75°.②The displacement reached a maximum value when implant anchorage was implanted into 1mm of cortical bone with 30° of angle,and its stress and displacement presented a decreasing trend with the increase of thickness of cortical bone.Conclusions：①The above research suggests that implantation angle from 60° to 75° would be a better choice in clinical operation.②The increase of thickness of cortical bone can improve the stability of implant anchorage.③When the thickness of cortical bone is greater than 1mm,Von Mises equivalent stress induced by 200g of orthodontic force under different implantation angles is within the safe range,and will not cause bone resorption and other problems.