个性化牙体预备导板离散建模技术研究

发布时间：2018-11-20 18:50

【摘要】：随着数字化技术在口腔修复领域的不断推广和应用,临床上对牙体的预备开始从传统的纯手工操作方式慢慢向借助辅助装置操作方式转变。利用数字化牙体预备导板装置不但能制备出更高精度的预备体,而且能大幅地提高手术效率,这将必定成为未来的主流治疗手段。本文针对牙体预备导板的临床应用特点,对牙体预备导板建模的关键技术进行了研究,主要研究内容和成果如下:(1)针对牙齿网格模型上的龈缘线获取,研究了一种基于曲率特征信息的自适应的提取算法。基于曲率特征信息确定特征点候选区域,凭借数理统计中相关系数动态确定搜索半径,以主成分的主方向为引导方向,自适应的迭代搜索特征点,并进行曲线拟合,得到光滑封闭的龈缘线。(2)针对预备导板支撑体的构建,提出了一种基于过渡截面的扫掠建模方法。在扫掠路径曲线的各节点处插入过渡截面,利用投影的方法获得各截面上的轮廓曲线,形成扫掠曲面,并通过插入随机离散点和Delaunay三角剖分方法获得封闭的扫掠体。(3)研究了三角网格轴面导轨模型的离散参数化建模技术。通过分析牙科车针和预备体之间的约束关系,确定轴面导轨的尺寸约束模型,实现了轴面导轨的参数化建模,并基于历史模型实现导轨模型的动态更新。在上述研究理论成果基础上,以VS2008为平台以及基于OpenGL图形库,完成了个性化牙体预备导板数字化建模软件模块的开发,并通过实例验证了系统的有效性和稳定性。
[Abstract]:With the development and application of digital technology in the field of dental prosthesis, the clinical preparation of teeth has gradually changed from the traditional manual operation to the operation with the aid of auxiliary devices. The use of digital dental preparation guide device can not only produce a higher accuracy of the preparation, but also greatly improve the efficiency of surgery, which will certainly become the mainstream treatment in the future. According to the clinical application characteristics of dental prefabricated guide plate, this paper studies the key technology of tooth preparation guide plate modeling. The main research contents and results are as follows: (1) for the gingival margin line acquisition on the tooth mesh model, An adaptive extraction algorithm based on curvature feature information is studied. The candidate regions of feature points are determined based on curvature feature information. The search radius is dynamically determined by the correlation coefficient in mathematical statistics. The principal direction of principal component is used as the guide direction, and the feature points are searched adaptively by iteration, and the curve fitting is carried out. A smooth and closed gingival margin line is obtained. (2) A sweeping modeling method based on transition section is proposed for the construction of pre-guide plate support. The transition section is inserted at each node of the sweep path curve, and the contour curve on each section is obtained by projection method, and the swept surface is formed. The closed swept body is obtained by inserting random discrete points and Delaunay triangulation. (3) the discrete parameterized modeling technique of triangular grid axial guide rail model is studied. Based on the analysis of the constraint relationship between the dental needle and the preparatory body, the dimension constraint model of the axial guide rail is determined, and the parametric modeling of the axial guide rail is realized, and the dynamic updating of the guide rail model is realized based on the historical model. On the basis of the above theoretical research results, the digital modeling software module of individualized dental preparatory guide plate is developed on the platform of VS2008 and based on OpenGL graphics library, and the validity and stability of the system are verified by an example.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783;TP391.7

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