以三维有限元法验证Spline种植体改性中齿状突起的数目与强度

Finite element analysis of stress distribution of Spline implant-abutment joint with different number of projections

背景:关于Spline种植体的前期研究发现,该种植体在不同载荷下的最大应力值均位于Spline齿状突起的根部。目的:针对Spline种植体齿状突起是其结构中的薄弱部位这一问题,从齿状突起数目方面入手,提出增加其强度的方法的假设:即考虑减少齿状突起的数目从而增大齿状突起的体积来增加强度,并用三维有限元方法检验这一假设的正确性。方法:采用Pro/Engineer Wildfire2.0软件建立相同直径和长度,不同突起数目(4个、5个、6个)的Spline连接方式的种植体-基桩模型。通过两种方法修改Spline模型界面,方法A为4个或5个突起的总体积与Spline种植体相同,方法B为4个或5个突起的突起间隔与Spline种植体相同。使用有限元软件Ansys Workbench 9.0进行三维有限元应力分析,对不同模型分别施加垂直200N、垂直500N、斜向100N(45°)载荷,观察不同载荷下不同突起数目的Spline种植体-基桩界面的应力情况,对其进行比较分析。结果与结论:方法A建立的模型,不论何种载荷下,随突起数目减小Spline突起的应力值均增加。方法B建立的模型,5个突起的种植体应力值较6个突起增大,4个突起的应力值与6个突起相当或稍小。提示通过减少突起数目来增加种植体强度的方法尚需进一步检验。

BACKGROUND：Spline implant has been shown to have maximum stress at Spline projection root under different loading. OBJECTIVE：To find a way to strengthen the Spline projections from projection numbers,namely to reduce projection number but increase projection volume,and to verify the accuracy by three-dimensional finite element analysis. METHODS：Pro/Engineer Wildfire 2.0 software was used to establish Spline implant-abutment model with identical diameter and length but different projection numbers（4,5,6）.The model interface was modified by two methods：by method A,the total volume of 4 or 5 projections was equal to Spline implant;by method B,the projection space of 4 or 5 projections was equal to Spline implant.Three-dimensional finite element analysis was used to determine stress distribution of the implant with different number of projections under vertical 200,500 N,oblique 100 N（45°）by Ansys Workbench 9.0 software. RESULTS AND CONCLUSION：For method A,stress on projections of the implant increased with reducing number of projections.For method B,implant with 5 projections displayed greater stress compared with 6 projections,and 4 projections showed similar or a little lower stress compared with implant with 6 projections.Results show that it requires validation to strengthen the Spline projections by reducing projection numbers.