基于逆向工程技术的烤瓷固定义齿基底支架计算机辅助设计

目的 探讨烤瓷固定义齿基底支架的计算机辅助设计（CAD）路线，确定合适的三维CAD方法。方法 选取1例上颌第二前磨牙缺失患者，获取其工作模型的三维数据。基于临床设计原则，在逆向工程软件Surfacer10．5平台中调用标准桥体数据，利用三维曲线、点云和曲面编辑工具，提取预备体边缘线和桥体龈面边界线，创建基底桥体空间形态和位置定位参考线，分别创建固位体基底冠轴面部分、肩台部分、桥体龈面和轴面，创建连接区、连接体轴线及连接体曲面。结果完成1例后牙3单位烤瓷固定义齿基底支架的CAD，设计出的修复体形态合理、表面光滑、边缘密合。结论 本项研究的设计路线可行，结果 具有一定的理论和实践意义，为国产口腔修复体计算机辅助设计与计算机辅助制作（CAD-CAM）系统的完善，提供了技术方法的参考。

Computer aided design for fixed partial denture framework based on reverse engineering technology

Objective To explore a computer aided design(CAD) route for the framework of domestic fixed partial denture (FPD) and confirm the suitable method of 3-D CAD. Methods The working area of a dentition model was scanned with a 3-D mechanical scanner. Using the reverse engineering (RE) software, margin and border curves were extracted and several reference curves were created to ensure the dimension and location of pontic framework that was taken from the standard database. The shoulder parts of the retainers were created after axial surfaces constructed. The connecting areas, axial line and curving surface of the framework connector were finally created.Results The framework of a three-unit FPD was designed with RE technology, which showed smooth surfaces and continuous contours.Conclusions The design route is practical. The result of this study is significant in theory and practice, which will provide a reference for establishing the computer aided design/computer aided manufacture(CAD/CAM) system of domestic FPD.