用实体建模法建立上颌第一磨牙隐裂的三维有限元模型  

Construcion of a three-dimensional finite element model of a cracked maxillary first molar by using solid modeling method

作　　者：殷霄[1] 张亚庆[1] 侯磊[2] 韩冰[1] 

机构地区：[1]陕西西安第四军医大学口腔医学院,710032 [2]陕西西安航天复合材料研究所,710025

出　　处：《牙体牙髓牙周病学杂志》2010年第3期143-146,共4页Chinese Journal of Conservative Dentistry

摘　　要：目的:通过裂纹实体建模方法建立上颌第一磨牙隐裂的有限元模型。方法:对正常上颌第一磨牙进行Micro-CT扫描,经调整后的断层图片使用MIMCS软件根据图像灰度进行拟合,分别建立带有结点、面信息的釉质和牙本质的STL格式三维模型。用MAGICS对STL文件进行处理,调整表面三角形质量并使釉牙本质界密合、均匀一致。之后将高质量的釉质、牙本质的STL模型导入有限元软件中,通过三维裂纹实体建模方法建立上颌第一磨牙隐裂的有限元模型,并应用断裂力学理论对裂纹部位网格进行手动修改,初步加力以验证模型的可行性。结果:建立了精细的上颌第一磨牙隐裂的有限元模型,裂纹网格能够反映裂纹尖端应力奇异性。结论:三维裂纹模拟的实体建模方法简单有效且易于实现,可以用于隐裂牙的裂纹扩展分析建模。AIM：To construct a three-dimensional finite element model of a cracked maxillary first molar by the solid crack modeling method. METHODS： An intact first maxillary molar was scanned with micro-CT. After pictures of every cross-section were adjusted, surface contours of enamel and dentin were fitted following tooth segmentation based on different gray scale using an interactive medical image control system （MIMICS）. Then enamel and dentin were separately converted into stereolithography files which were consisted of the nodal points and surfaces information. A stereolithography handling software （MAGICS） was used to reestablish the congruence of the interfacial mesh between enamel and dentin. Then the remesh operations were applied to the STL model to improve the quality of the triangles. These high quality STL files were imported into finite element analysis software. The crack part was established on the entire model to accomplish the modeling. The crack part was meshed with particular method based on fracture mechanical theory by using singular element, and an initial analysis was taken to testify the dependability of the model. RESULTS： A refined three-dimensional finite element model of a cracked first maxillary molar was constructed and meshes of the crack could reflect the stress singularities in crack-tip. CONCLUSION：The solid modeling method is simple and efficient and can be carried on easily. It is suitable to establish a cracked tooth model for crack growth analysis.

关 键 词：牙隐裂综合征 有限元分析 MICRO-CT 奇异单元 

分 类 号：R780.4[医药卫生—口腔医学]