应用反求工程方法重建残冠和(或)残根的三维数字模型

Study on 3D reconstruction of a digital model of residual crown and root by reverse engineering and rapid prototyping

目的探讨用反求工程(RE)方法实现残冠和(或)残根数字模型三维重建的方法,为个体化桩核的CAD设计与制作奠定基础。方法 (1)选取牙体硬组织完整的离体牙10颗,按桩核预备标准预备后分别用螺旋CT机和Mi-CT机进行扫描,所获得数据以DICOM格式文件进行存储;(2)应用Mimics软件将螺旋CT机和Mi-CT机扫描获得的数据分别进行处理,获得牙齿标本的数字模型,Geomagic 9.0软件进行三维测量,同时生成STL格式文件;(3)用游标卡尺对牙齿标本进行测量,并与软件测量所获得的数据进行比较,采用配对比较t检验进行统计学分析。结果 (1)用反求工程方法对离体牙标本实现了三维重建,获得其数字模型。Mi-CT数据源三维数字模型较螺旋CT数据源三维数字模型而言,模型边缘轮廓更为锐利、清晰;(2)应用螺旋CT机和Mi-CT机扫描获得的数字模型,经软件测量,与牙齿标本测量结果相比均无统计学意义(P>0.05)。结论用反求工程方法能准确、快速地实现残冠和(或)残根模型的三维重建。

Objective To evaluate the feasibility of 3D reconstruction of digital model of residual crown and root by reverse engineering （RE） and rapid prototyping. Methods Ten intact teeth （anterior teeth or premolars） were prepared according to the standards of post and core and scanned by spiral CT and micro-CT. The data in DICOM format were collected and processed by the software MIMICS, and then the teeth＇s digital model were reconstructed. Careful measurements and analysis were carried out both in teeth prototypes by a vernier caliper and in the digital models by the software Geomagic 9.0. Results 3D reconstructions of digital models of teeth were successfully performed by reverse engineering. There was no significant statistical difference between the data obtained from the digital models, as well as the data obtained from the measurement of the teeth prototypes. Conclusion The combination of RE and RP is an effective way for 3D reconstruction of digital model of residual crown and root.