主桩与辅桩联合应用对扁形根管的前磨牙修复后应力影响的有限元分析

发布时间：2018-11-05 07:57

【摘要】：目的针对扁形根管的前磨牙，通过三维有限元的方法分析在纤维桩主桩与辅桩联合应用和只应用纤维桩主桩的情况下，牙体和修复体上的应力大小及分布情况，为优化扁形根管的前磨牙桩核冠修复体的设计提供理论参考。方法 1.根据王惠芸报道数据，选择离体的正常下颌第一前磨牙19颗，应用CBCT垂直牙体长轴进行扫描，层厚0.1mm，获取断层图像358张。根据三维影像，再从这19颗中选取扁形单根管的下颌第一前磨牙一颗，按标准根管治疗程序及桩道预备方法预备此牙，目的是为了获得接近临床实际的桩道，此后以与第一次同样的条件再次进行CBCT扫描。 2.图像经Mimics、Geomagic studio、CATIA、ANSYS Workbench软件处理，建立只应用纤维桩主桩的桩核冠修复体的分析模型A与桩道内联合应用纤维桩主桩和辅桩的分析模型B。 3.在所建立的三维分析模型的基础上，利用ANSYS Workbench软件计算下颌第一前磨在两种不同形式桩核冠修复方式下的应力情况，最后根据牙体和修复体上的应力大小及分布情况进行分析。结果 1.通过计算机辅助设计，建立了仅应用纤维桩主桩的桩核冠修复体三维有限元模型A与纤维桩主桩与辅桩联合应用的桩核冠修复体三维有限元模型B。 2.主桩与辅桩联合应用与只应用主桩相比较，各种加载角度下，牙体组织上的等效应力与最大主应力峰值虽然略有降低，但没有明显差异，主桩与辅桩联合应用时牙体组织上高应力区范围略有减小，应力的分布也更趋向均匀。 3.主桩与辅桩联合应用与只应用主桩相比较，当应力与牙体长轴成角度加载时，桩上的等效应力与最大主应力峰值呈减小趋势，且桩上的应力变化较牙体组织上大。 4.树脂上的剪切应力主要集中于桩尖的部位，在同种加载角度下，模型A与B中树脂上剪切力值相差不大，同一模型在不同加载角度下，剪切力峰值随着加载角度的增加明显增大。 5.同一模型中，随着加载角度的增大牙体组织上的等效应力峰值和应力集中区域也随之增大，且增幅较为明显。结论 1.主桩与辅桩联合应用与只应用主桩相比较，载荷与牙体长轴成角度加载的情况下，牙体组织上和桩上的等效应力与最大主应力峰值略有降低，高应力区范围略有减小，应力的分布也更趋向均匀，但差别并不明显。表明纤维桩辅桩对扁形根管的前磨牙应力的影响不显著。 2.无论是否使用纤维桩辅桩，牙根上的高应力区域均集中于颈1/3。随着应力与牙体长轴加载角度的增大，模型A与B牙体组织上应力均呈明显增大的趋势，90°加载时可对修复体造成破坏性的影响。 3.相比较纤维桩辅桩对修复体应力的影响来说，，加载角度的影响更大。
[Abstract]:Objective to analyze the stress distribution and stress distribution of the flat root canal premolars in the case of fiber pile and auxiliary pile combined with fiber pile and only fiber post. It provides a theoretical reference for optimizing the design of premolar post-core crown prosthesis with flat root canal. Method 1. According to the data reported by Wang Huiyun 19 normal mandibular first premolars were selected and scanned with CBCT vertical long axis. The slice thickness was 0.1 mm and the tomographic images were obtained. According to the 3D images, one of the first mandibular premolars of the flattened single root canal was selected and prepared according to the standard root canal treatment procedure and the method of the post canal preparation, in order to obtain a post canal close to the clinical reality. The CBCT scan is then performed again under the same conditions as the first time. 2. The image was processed by Mimics,Geomagic studio,CATIA,ANSYS Workbench software, and the analysis model of the crown restoration with only fiber pile was established. Model A was combined with the analysis model of fiber pile main pile and auxiliary pile in pile road. On the basis of the established three-dimensional analysis model, the stress of mandibular first anterior grinding under two different forms of post and core crown restoration was calculated by ANSYS Workbench software. Finally, the stress distribution and size of tooth and prosthesis were analyzed. Result 1. By means of computer aided design, a three-dimensional finite element model B. 2, which is used only for fiber pile main pile and auxiliary pile, is established. Compared with the application of main pile and auxiliary pile, the equivalent stress and the peak value of maximum principal stress in dental tissue decreased slightly, but there was no significant difference between them. The range of high stress zone in dental tissue decreases slightly and the distribution of stress tends to be more uniform when combined with main pile and auxiliary pile. 3. When the stress is loaded at an angle to the long axis of the tooth, the equivalent stress and the peak value of the maximum principal stress on the pile tend to decrease, and the change of the stress on the pile is larger than that on the tooth. 4. The shear stress on the resin is mainly concentrated on the tip of the pile. At the same loading angle, the shear stress on the resin in model A and B is not different, and the shear stress on the same model is at different loading angles. The peak value of shear force increases obviously with the increase of loading angle. 5. In the same model, the peak value of equivalent stress and the region of stress concentration increase with the increase of loading angle, and the increase is obvious. Conclusion 1. When combined application of main pile and auxiliary pile is compared with only main pile, the equivalent stress and peak value of maximum principal stress decrease slightly, and the range of high stress region decreases slightly when the load is angular to the long axis of the tooth. The stress distribution tends to be more uniform, but the difference is not obvious. The results showed that the stress of premolar of flat root canal was not significantly affected by fiber pile. 2. Whether or not the fiber pile was used, the high stress area on the root was concentrated on the neck 1 / 3. With the increase of stress and long axis loading angle of tooth, the stress on model A and B tooth tissue is obviously increasing, and 90 掳loading can have a destructive effect on the restoration. 3. Compared with the effect of fiber pile auxiliary pile on the stress of the restoration, the effect of loading angle is greater.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.3

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