纤维桩核冠修复上颌中切牙牙体缺损的应力分析

Stress Analysis of Restored Damaged Maxillary Central Incisor

目的研究不同程度缺损的上颌中切牙行纤维桩、全瓷冠修复后纤维桩、粘接剂、牙周膜、牙槽骨等的应力变化,以及这种变化与牙体缺损程度的关系。方法螺旋CT扫描上颌中切牙,运用Mimics软件、Ansys软件建立7种牙体缺损上颌中切牙的三维有限元模型,模拟纤维桩全瓷冠修复、咬合加载,记录纤维桩、粘接剂、牙周膜、牙槽骨的Von Mises应力和最大拉应力。结果纤维桩、粘接剂、牙周膜、牙槽骨的应力大小和分布随牙体组织的减少没有明显变化,粘接剂的应力值在0 mm牙本质肩领时稍增大。结论牙体组织的减少对纤维桩、粘接剂、牙周膜、牙槽骨的应力大小和分布无明显影响。

Objective To study the stress changes of different damaged maxillary central incisor restored with fiber post using three dimensional finite element method,to analysis the role of damaged degree in determining the stress distribution in structures.Methods Three dimensional finite element models of maxillary central incisor with various remaining tooth structure restored with fiber post all-ceramic crown were established by screw CT,Mimics software,FreeFrom software and Ansys software.A 100 N static load was applied at 45 degree to the long axis of the tooth at incisal 1/3.The Von Mises stress and maximal tensile stress were recorded.Results The stress level and distribution in fiber post,cement,pericementum,crest bone were not change when decrease the remaining tooth structure,only the stress level of cement increase little when remaining 0 mm dentin ferrule.Conclusion The decrease of tooth structure had no influence to the stress level and distribution of fiber post,cement,pericementum,crest bone.