利用工业CT扫描图像重建牙列缺损的几何模型

目的:介绍一种获取牙列缺损石膏模型三维数据的方法,为实现可摘局部义齿CAD/CAM奠定基础。方法:利用低能量X射线工业计算机断层扫描机(industrialcomputedtomography,ICT)扫描牙列缺损石膏模型,获得该模型的ICT图像,经过图形图像处理,获取表面轮廓三维数据;矢量化后,将数据输入通用逆向工程软件系统,重建牙列缺损的三维CAD模型。在此基础上,在CAD/CAM软件系统中构建可摘局部义齿支架的三维数字模型。数据传输格式为STL。结果:获得的点云数据密集均匀,未见扫描盲区;三维重建的牙列缺损CAD模型结构清晰,完成了可摘局部义齿支架三维模型的构建。结论:与医用CT相比,ICT扫描方法空间分辨率高,精确度高,可以作为一种获取牙列缺损石膏模型三维数据的可靠方法。

The reconstruction of geometric models of dentition defects based on 3-dimensional industrial computed tomography image

PURPOSE: A technique on data capture of plaster models for building 3-dimensional geometric models of dentition defects was presented for the purpose of further computer-aided design and manufacture(CAD/CAM)of removable partial denture. METHODS: A plaster model with dentition defects was scanned with low energy X-ray industrial computed tomography (ICT) for ICT image. The data after image processing and vectorization were transferred to a customized reverse engineering software system, and a CAD model of dentition defects was reconstructed. Then a 3-dimensional digital model of removable partial denture framework was created with CAD/CAM software system. Import/export of the data was in STL format. RESULTS: Dense and uniform data points without blind areas were acquired and the structure of the reconstructed CAD model of dentition defects was clean and smooth. CAD model of framework was then obtained. CONCLUSIONS: The method presented is practical for 3-dimensional data capture, and it helps build reliable 3-dimensional geometric models with better spatial resolution and higher precision than conventional technique with medical CT.