上颌第一磨牙近中舌尖缺损伴隐裂修复设计的有限元分析  

Finite element analysis of the prosthodontic design for maxillary first molar mesio-lingual cusp defect with subfissue

作　　者：邱晓霞[1] 邢旭娜[1] 张海燕 陈杰[1] 郭东晓 薛蕊[1] 

机构地区：[1]郑州大学口腔医学院修复科,450052 [2]郑州市口腔医院种植科 [3]郑州市金水区瑞佳口腔门诊部

出　　处：《实用口腔医学杂志》2016年第1期43-47,共5页Journal of Practical Stomatology

基　　金：河南省卫生厅科技攻关计划项目(编号:201403121)

摘　　要：目的:研究上颌第一磨牙近中舌尖缺损同时伴有不同深度隐裂纹及不同修复方式修复后其应力分布以及裂纹扩展情况。方法:利用锥形束CT及有限元软件,建立上颌第一磨牙近中舌尖缺损伴缺损断面有不同深度隐裂纹的有限元模型,对模型分别采用不同修复方式进行修复,并模拟在不同咬合力下的受力情况,观察分析裂纹的等效应力值及应力分布、裂纹J积分值、牙本质最大主应力值。结果:采用金属桩加全瓷冠修复3种深度隐裂牙时,裂纹的等效应力值、J积分值、牙本质最大主应力值均最小。裂纹深度增加时牙齿垂直向和斜向受力时的裂纹等效应力值、J积分值、牙本质最大主应力值均明显增大。每一种修复方式中4种受力方向时裂纹等效应力值、J积分值、牙本质最大主应力值均为为200 N、90°>200 N、45°>600 N、0°>200 N。结论:采用弹性模量大的金属桩加全冠修复时,隐裂纹扩展及牙折的可能性较小;隐裂纹越深修复后隐裂纹扩展及牙折的可能性越大;侧向力比垂直向力对裂纹及牙本质的应力变化影响大且易造成裂纹扩展和牙折。Objective： To study the prosthodontic design for the treatment of maxillary first molar mesio-lingnal cusp defect with subtis- sue. Methods： A finite element model of maxillary first model, including mesio-lingual cusp defect with suhfissue, periodontal support- ing tissue and a section of the maxilla was established by cone beam CT. Different prosthodontic designs for respective restoration and simulating different bite force were adopted, the Von Mises stress, maximum compressive stress and the crack distribution, J integral and the root displacement were analysed. Results： In the metal pile restoration model, the stress, JINT value and the equivalent stress and displacement of root were the smallest. With the increase of crack depth of the vertical and oblique tissue, the equivalent levels of stress （equivalent stress of J integral） , the stress experienced by the dentin along with the peak of the maximum principal, increased signifi- cantly. Under 4 kinds of force direction and 3 repair methods, the equivalent stress peak value, J integral dentin stress, maximum prin- cipal stress peak value and dentin stress peak value of the cracks was 200 N, 90° 〉200 N, 45° 〉600 N, 0°〉200 N. Conclusion： High elastic modulus and all ceramic crown may lead to minimal equivalent stress, J integral, dentin equivalent stress and maximum principal stress. When subfissure is repaired, teeth fracture remains possible and any possible propagation may exist. The effect of later- al force on the crack and the dentin is greater than that of vertical force for crack expansion and tooth fracture.

关 键 词：上颌第一磨牙缺损伴隐裂 有限元 桩 树脂充填 冠 

分 类 号：R783.3[医药卫生—口腔医学]