牙齿预备体洞缘线的截面析构提取方法

Section destruction extracting method for the cavosurface margin of tooth preparation

CAD/CAM技术的嵌体修复方法在修复缺损牙体的临床应用中日益深入和广泛。洞缘线的提取质量决定了嵌体与预备体的配合精度,影响补牙治疗的质量,因而洞缘线的提取具有极为重要的意义。文中提出洞缘线的截面析构提取方法,从牙齿预备体扫描点云数据中提取洞缘线数据点,相对于模型全局特征的提取方法,截面析构法不会产生冗余无意义的特征线,提取准确且快速,再从洞缘线数据点中提取特征进而获得牙齿预备体洞缘线。由此获得的洞缘线不仅能满足误差条件,而且求取速度快,洞缘线的特征点数少,便于口腔临床设计使用。计算结果表明,所提出的截面析构提取方法能够满足临床误差使用要求,也为各种洞缘线的提取提供了一种有效的方法。

The inlay restoration method of CAD/CAM technique has become increasingly intensive and extensive in the clinical application of repairing the defect tooth. The extraction quality of cavosurface margin determines the precision of inlay and tooth preparation, and seriously affects the quality of dental treatment, so the extraction of the cavosurface margin is vital significance. The extraction method of cavosurface margin based on section destruction is proposed, which is that extracts the data points of the cavosurface margin from the scanning point cloud data of the tooth preparation, and compared to the extraction method towards the global characteristics of the model, it extracts more accurately and quickly, thus, redundant meaningless feature line will not be generated. To obtain the cavosurface margin of tooth preparation, cavosurface margin data points are firstly extracted from the scanning point data, and then features are extracted from the cavosurface margin data points. As a result, the obtained cavosurface margin with faster determining velocity and less feature points satisfies the error conditions, which facilitates the use of oral clinical design. The calculation results show that the proposed method can meet the requirements of clinical error and provide an effective way for the extraction of various kinds of cavosurface margin.