【作者】 孙士慧；

【导师】 王璐；

【作者基本信息】 重庆医科大学 ， 口腔临床医学， 2011， 硕士

【摘要】 目的:应用螺旋CT扫描的原始DICOM数据,建立上颌后牙及固定桥的三维有限元模型,分析其载荷条件下的生物力学特性,并对三种不同材料的全瓷固定桥进行有限元分析。方法:①用螺旋CT对牙列完整、解剖结构正常的成人干颅进行断层扫描,将所得DICOM数据输入MIMICS软件,选择上颌第二前磨牙、第一磨牙和第二磨牙及相应颌骨组织进行三维图像重建。将信息导入三维有限元分析软件ANSYS中进行切割,建立后牙三单位固定桥的三维有限元模型。②在ANSYS软件中对固定桥模型进行加载,分析其各部位的位移及应力变化。③将固定桥的内冠材料分别设定为IPS e.max press、In-Ceram Alumina和氧化锆,利用ANSYS软件对其受载后的位移及应力分布进行分析。结果:①建立了上颌后牙三单位固定桥的三维有限元模型,模型包括上颌骨、牙齿、全瓷固定桥等结构,共包含67731个节点,344188个单元,具有良好的几何外形,可任意提取某一部分进行研究,具有可拓展性。②对固定桥进行加载后,其舌侧龈缘处位移最大;连接体区应力最大,且龈方的应力大于牙合方。③对三种材料的全瓷固定桥分别加载,氧化锆组的位移及应力小于其他两组,后两组间相差不大。结论:以应用螺旋CT扫描为基础,结合使用MIMICS和ANSYS软件建立较复杂的固定桥三维有限元模型,几何相似性较高,且过程更加简单快捷,便于应用和计算。全瓷固定桥受载后应力主要集中在连接体处,且龈方应力较大,提示该处是全瓷固定桥最脆弱的部位,应当加固。其次舌侧龈缘处的位移及应力较大,受力大于颊侧。比较IPS e.max press、In-Ceram Alumina和氧化锆三种常用的全瓷固定桥,氧化锆稍优于IPS e.max press和In-Ceram Alumina组,后二者之间差别不大。三种材料均可用于后牙固定桥的修复。更多还原

【Abstract】 Objective: To construct the three-dimensiona finite elemet model of the maxillary postetior fixed partial denture (FPD) with the original DICOM data of spiral CT, investigate the biomechanics characters of the FPD by loading, and and carries on the finite element analysis to three different material’s all-ceramic fixed partial denture.Methods:①A macerated human skull was scanned with spiral CT and the original DICOM data were imported into MIMICS software. The three-dimensional geometrical model containing the mandibular second premolar,mandibular first molar, mandibular second molar and the corresponding alveolar bone was constructed. The three-dimensional finite elemet model of the maxillary postetior fixed partial denture was constructed after slotting in three dimensional finite element analysis software ANSYS.②On the basis of the three-dimensional model of the first Part,we observed the load conditions on pontic of the maxillary FPD and analysed the stress distribution and displacement with a finite element program ANSYS.③Seting the core crown material of the fixed partial denture is IPS e.max press, In-Ceram Alumina and Zirconia, we analysed the stress distribution and displacement with a finite element program ANSYS.Results:①The establishment three-dimensional finite element model of maxillary postetior all-ceramic fixed partial denture, which was made up of 67331 nodes and 344188 units, included maxilla, teeth and all-ceramic fixed partial denture. Model and modeling had a good geometric similarity. So it had scalability and it could be splitted randomly or extracted a certain part for a separate study.②According to the FEA analysis after loading on the ponitic, the displacement in gingival margin of lingual surface was most significant , the stress occurred in connective area, and the gingival was more dignificant than occlusal.③Loading separately to three material’s all-ceramic fixed partial denture, the displacement and the stress of Zirconia group’s was smaller than other two groups, during the latter two groups differs not in a big way.Conclusion: The method to construct a complex fixed partial denture three-dimensional finite element model is improved by using the MIMCS and ANSYS software which based on the spiral CT. what’s more it was easy to apply and calculate.The connective aera was the frailest spot of all- FPD, must be reinforced.The displacement and stress in gingival margin of lingual side was significant than the buccal side.Compared the three kind material of commonly used all-creamic FPD, the Zirconia surpassed IPS e.max press and In-Ceram Alumina group, but the latter two groups had no significant difference. The material of IPS e.max press,In-Ceram Alumina and Zirconia could be used for the postetior fixed partial denture.更多还原