有和无全冠保护时不同材料的后牙桩核修复体有限元模型的应力分析  

The three-dimension finite element analysis on stress of different materia post-core of posterior tooth with or without PFM

作　　者：付钢 任嫒姝[2] 王璐[1] 夏熹[1] 黄茜[1] 

机构地区：[1]重庆医科大学附属口腔医院修复科 [2]重庆医科大学附属口腔医院正畸科,重庆400015

出　　处：《重庆医科大学学报》2007年第12期1288-1291,1300,共5页Journal of Chongqing Medical University

基　　金：重庆医科大学校级课题基金0200100454

摘　　要：目的:比较四种不同桩核材料的后牙核桩修复体,在有和无全冠保护条件下,其牙本质位力的大小和分布,从而指导临床合理地选用修复材料。方法:通过磨片法结合数码相机获取断层图片的建模方法,建立上颌第一磨牙近中腭尖缺损的桩核冠有限元模型,分别分析在有和无全冠保护条件下,中熔合金桩、复合树脂桩、汞合金桩,铸瓷桩修复后的牙本质应力大小及分布状况。结果:1有全冠保护的条件下的上颌第一磨牙桩核修复体的应力峰值均要明显低于无全冠保护者,且二者的应力分布方式也明显不同。2有全冠保护的条件下的上颌第一磨牙桩核冠修复体,其不同桩核材料的选择对牙本质应力峰值、剩余牙本质的应力大小、根管内的应力分布无明显影响。但高弹性模量的中熔合金桩核,汞合金桩核,铸瓷桩核改变了牙体正常的应力分布模式;复合树脂桩核对牙体正常的应力分布模式无明显改变。结论:在本实验条件下的正常牙合力作用下,全冠的使用对死髓牙的保护至关重要,它是后牙桩核修复体成功与否的关键。同时,不同桩核材料的选取,对桩核加全冠修复的后牙发生牙折的影响无明显差别,且极少发生。Objective：To compare influence the residual dentin stress of posterior teeth post-core different materials with or without porcelain fused metal crown （PFM）,in order to instruct clinically rational choice of materials. Method：Models were created by abrasive method which pictures were acqiured with digital camera. Three-dimensional models of maxillary first molar short in medial palatal cusp were constructed and restored with of different materials post-core on condition of having or not having PFM.Then the magnitude and distribution of model residual dentin stress were analyzed by the three-dimension finite element analysis. Result： 1 When maxillary first molar which is short in medial palatal cusp was restored with post-core and porcelain fused mental crown,its peak value of stress was evidently less than that with post-core but without porcelain fused mental crown,meanwhile,they had different stress distribution. 2 When maxillary first molar which is short in medial palatal cusp was restored with post-core and porcelain fused mental crown,post-core of different materials had little influence on peak value of stress of residual dentin,but post-core of high elasticity modulus change normal dentin stress distribution,while post-core of low elasticity modulus did not. Conclusion：On the condition of normal occlusal force,PFM is extremely important to protect no-vital tooth,which is crucial for successful post-core crown. Meanwhile,post-core of different materials show little difference in fracturing rate of tooth restored with post-core and porcelain fused mental crown, and the fracture namely happen.

关 键 词：三维有限元 应力 桩核 全冠 

分 类 号：R783.3[医药卫生—口腔医学]