微小种植体支抗的三维有限元分析

目的 利用三维有限元进行微小种植体应力分析,寻找最适合正畸临床使用的微小种植体。方法 利用ANSYS软件建立10mm×20mm×30mm的颌骨骨块三维有限元模型;同时建立的长度为7mm、9mm、11mm,螺纹顶角为30°、60°、90°的9种圆柱状有螺纹微小种植体三维有限元模型;模拟微小种植体植入颌骨内并建立植入后模型,对微小种植体骨界面进行应力分析。结果 经ANSYS软件对微小种植体骨界面的应力分析,在不同角度的微小种植体中,螺纹顶角为60°的微小种植体三维有限元模型周边最大应力值最小,最适于临床使用。不同长度的微小种植体中,长度为7mm的微小种植体三维有限元模型周边最大应力值明显大于其他两种,不适用于正畸临床。9mm和11mm微小种植体三维有限元模型周边最大应力值差别不大,11mm微小种植体三维有限元模型周边最大应力值略小于9mm微小种植体三维有限元模型周边最大应力值。结论 螺纹顶角为60°,9mm以上的微小种植体适于正畸临床做为支抗使用。

Three dimensional finite element analyses for mini-implant anchorage

Objective To find a mini-implant of compatible orthodontic clinical application by three dimensional finite element analyses.Methods After a three-dimensional finite element model of 10mm×20mm×30mm jawbone and nine kinds of mini-implants,whose respective lengths were 7mm,9mm,11mm and different screw angles were 30°,60°,90°,were established by ANSYS.We analyzed the stresses of mini-implant-bone interface.Results The stress of mini-implant-bone interface was analyzed by ANSYS.Between mini-implants of different screw angles,the maximum values of 60° screw angle were the least.Between mini-implants of different lengths,the maximum values of 7 mm mini-implant were evidently greater than those of the 9 mm and 11 mm mini-implants,and there wasn＇t obvious change between 9 mm mini-implant and 11 mm mini-implant.Conclusions A mini-implant whose screw angle is 60° and length is beyond 9mm is more appropriate to be used as orthodontic anchorage.