固定桥基牙牙周膜厚度不同时牙周膜内的应力分析

Stress analysis of periodontal membrane of fixed abutment tooth with different thickness

目的:研究固定桥基牙牙周膜厚度不同时牙周膜内的应力分布,为临床工作提供理论依据。方法:采用螺旋CT扫描获取健康人下颌骨、牙齿及牙周支持组织的二维图像,通过图像合成软件建立三维数字模型,并应用三维有限元分析软件生成下颌后牙固定桥的三维有限元分析模型。在相同垂直载荷和水平载荷情况下,分析固定桥基牙牙周膜厚度不同时牙周膜内的应力分布。结果:当固定桥基牙牙周膜厚度小于0.1mm时,牙周膜内应力最大值无变化;当固定桥基牙牙周膜厚度大于0.1mm小于0.4mm时,牙周膜内应力最大值随牙周膜厚度增加而增大但非线性关系;当固定桥基牙牙周膜厚度大于0.4mm时,牙周膜内应力最大值不随牙周膜厚度增加而增大。结论:固定桥基牙牙周膜厚度在一定范围内影响牙周膜内的应力分布。

AIM:To study the stress distribution of periodontal membrane of fixed abutment tooth with different thickness,and provide theoretical basis in clinic. METHODS:Two dimensional images of mandible bones,teeth and periodontal supporting tissue of healthy people were scanned by spiral CT.Three dimensional digital model was developed by imaging software.The three dimensional finite element analysis model of fixed denture on mandible posterior teeth was then developed.Stress distribution of periodontal membrane loaded with the same vertical and horizontal forces was analyzed during different thickness of periodontal membranes around abutments. RESULTS:There was no change in maximum stress when the thickness of periodontal membrane of fixed abutment tooth was less than 0.1 mm.When the thickness of periodontal membranes was between 0.1 mm and 0.4 mm, the maximum stress of periodontal membranes increased with the increase of the thickness of periodontal membranes,but there was non linear relationship between them.There was no change in the maximum stress of periodontal membranes with the increase of the thickness of periodontal membranes when the thickness of periodontal membranes was more than 0.4 mm. CONCLUSION:In some scope, the thickness of periodontal membranes of fixed abutments tooth has an influence on the stress distribution of periodontal membranes.