纤维桩与金属桩核修复磨牙牙体缺损的三维有限元应力分析  

Three-dimensional finite element analysis of the restoration with fiber post or metal post core for structure defect of the molar

作　　者：田力丽[1] 梁伟[2] 李凌旻[2] 麦汉超[2] 

机构地区：[1]卫生部中日友好医院口腔科,主任医师北京100029 [2]北京航空航天大学航空科学与工程学院,副教授北京100083

出　　处：《口腔颌面修复学杂志》2008年第4期280-282,290,共4页Chinese Journal of Prosthodontics

基　　金：卫生部中日友好医院院级课题(20053056)

摘　　要：目的:通过对磨牙牙体破坏较大的牙体缺损,采用纤维桩与铸造镍铬合金桩核、金合金桩核修复进行三维有限元应力分析,为临床应用提供一定的理论依据。方法:运用逆向工程技术法建立上下颌第一磨牙牙尖交错及尖对尖咬合状态的三维有限元模型,于上颌第一磨牙牙颈部平面施加均布载荷,进行静力与冲击动力计算,观察牙本质Mohr应力值的变化。结果:静载及动载下3种桩核修复,牙本质最大Mohr值均小于牙本质拉伸极限强度;牙本质最大Mohr值均位于根分歧部位,以纤维桩修复者为小;金合金桩核对减轻牙颈部应力明显;冲击载荷较静载下的应力变化-冲击系数均接近1。结论:3种桩核修复在临床上虽均可行,但建议临床上除牙颈部的的牙体组织过于薄弱或修复牙体组织缺损时固位需要外,尽量不使用桩核;其中,以纤维桩和金合金桩核为好;在有限元应力分析中,静载的研究是可行的。Objective： To make three-Dimensional finite element analysis of the restoration with fiber post or cast NiCr alloy post core or Au alloy post core for structure defect of the molar and to provide a guideline for the clinic. Methods： The research adopted reverse engineering technology to build the 3-dimensional finite element model. The form of the intercuspal occlusion and cusp to cusp occlusion of the maxillary and mandibular first molar were simulated. The load of even distribution was exerted on the plane of dental neck of the maxillary first molar. The static loads and the impact dynamic were calculated. The change of Mohr stress values of dentin was observed. Results： Under the static loads and the dynamic impact, the maximum Mohr stress values of dentin of the restoration with three kinds post core were all within the stretch limit strength of dentin. The maximum Mohr stress values of dentin were located in root fureation. During these restorations, the Molar stress values of dentin of the restoration with fiber post were the smallest. The impact ratio （the stress change between impact loads and static loads） was all closed to 1. Conclusions： Although the restoration with three of kinds post core were all feasible, it is suggested that the post cores had better not use in .the clinic if dental neck is not weakly very much or the restoration of teeth structure defect need not strengthen retention. It had better use fiber post and Au alloy post core. The research about static loads is feasible during three-dimensional finite element analysis.

关 键 词：纤维桩 金属桩核 三维有限元 静力 冲击动力 

分 类 号：R783[医药卫生—口腔医学]