静态载荷模拟修复下颌磨牙残冠的应力分析  

Stress analysis of residual crown of lower molar after simulated restoration under dead load

作　　者：连克乾[1] 陈应明[2] 许鸿生[1] 胡玲玲[3] 林尔坚[2] 

机构地区：[1]中山大学附属第一医院口腔科,广东省广州市510080 [2]中山大学附属第一医院放射科,广东省广州市510080 [3]华南理工大学交通学院应用力学系,广东省广州市510641

出　　处：《中国临床康复》2005年第26期150-151,i0007,共3页Chinese Journal of Clinical Rehabilitation

基　　金：广东省卫生厅科研基金资助项目(A2002153)~~

摘　　要：目的:对垂直静态载荷下模拟天然牙齿与金钯合金带桩嵌体的等效应力云图进行比较,分析金钯合金带桩嵌体修复下颌磨牙残冠的等效应力分布。方法:实验于2003-11/2004-12在华南理工大学交通学院应用力学系完成。从6颗离体的形态正常的人右下颌第一磨牙中,选取密合度最好且形态接近临床要求的1颗,应用螺旋CT断层扫描技术和图像合成软件,建立模拟的下颌第一磨牙和带桩嵌体修复的下颌第一磨牙残冠的三维有限元模型。在垂直向加载的情况下,应用有限元分析软件分别对其应力进行分析。结果:从6颗右下颌第一磨牙中选取1颗建立三维有限元模型。等效应力云图显示,在垂直向加载的情况下,金钯合金带桩嵌体修复后剩余牙体的各个部位的应力均比模拟天然牙小,应力比较集中在远中牙颈周围,尤其是在牙根内侧,并且颊侧比舌侧受到的等效应力稍大。结论:垂直向静态载荷下,金钯合金带桩嵌体使修复后的下颌第一磨牙残冠等效应力降低,但等效应力相对集中于远中牙颈,尤其是牙根内侧的颊侧处。提示对固位形比较差的牙体缺损应通过全冠修复或带桩嵌体修复的形式予以治疗。AIM： To compare the equivalent Von-mises stress nephogram between the simulated natural teeth and the gold-palladiu alloy inlay with peg under dead load, and analyze the equivalent stress distribution of gold-palladiu alloy inlay with peg for the restoration of residual crown of lower molar. METHODS： The experiment was done in the Department of Applied Mechanics, College of Traffic and Communications, South China University of Technology from November 2003 to December 2004. One molar that has the best occlusion and meets the clinical requirement most, were selected from 6 human right lower first molars ex vivo with normal shape. Helical CT scanning technique and imaging synthetic software were used to establish simulated lower first molar and a three-dimensional finite element model of residual crown of lower first molar restored by inlay with peg. Under the vertical loading condition, three-dimensional finite element software was employed to investigate the stress distribution of both. RESULTS： A three-dimenslonal finite model was established in the selected first molar from the 6 right lower first molars. From the equivalent Von-mises stress nephogram, it was shown that under the vertical loading condition, the stress of each part of the residual tooth restored by the goldpalladiu alloy inlay with peg was lower than that of the simulated natural tooth. At the same time the stress centralized in the peripheral distal and central distal neck, especially in the inside root of tooth, and bigger in buccal sided than in lingual side. CONCLUSION： Under the vertical loading condition, the equivalent Vonmises stress of residual crown of lower first molar restored by gold-palladiu alloy inlay with peg is decreased, but it concentrates in the distal and central neck of the tooth relatively, especially the buccal side of inside root of tooth. So, it is concluded that tooth loss with poor retention form should be restored by full crown or inlay with peg.

关 键 词：生物力学 牙应力分析 根管充填 牙修复体 下颌骨 下颌第一磨牙 应力分析 嵌体修复 磨牙残冠 模拟 

分 类 号：R781.05[医药卫生—口腔医学] R783.6[医药卫生—临床医学]