Zuskova Lucie, Mortadi Noor A Al, Williams Robert J, Alzoubi Karem H, Khabour Omar F
Dental Hospital, University Hospital of Wales, Heath Park, Cardiff, CF14 4XW, UK.
Department of Applied Dental Sciences, Jordan University of Science and Technology, Faculty of Applied Medical Sciences, Irbid, Jordan.
Int J Dent. 2019 Jul 7;2019:7310175. doi: 10.1155/2019/7310175. eCollection 2019.
The aim of this study was to investigate the effect of computer-aided design/computer-aided manufacturing (CAD/CAM) procedures on the overall fit of metal copings.
A standardized die was made in die stone of an upper right molar prepared for a full crown. The die was digitalized by an Identica Blue Light Scanner, and the coping substructure was designed using CAD software. Ten milled specimens and ten laser-sintered specimens were manufactured by Renishaw plc based on the generated file by the software. All twenty copings were digitized by the Identica scanner, and the data were superimposed with the original premanufacturing data file of the prepared full crown. Using the Geometric Modelling Library (GML) package, the fit discrepancies were displayed as colour maps showing discrepancies in three dimensions. Each map was made up of thousands of data points carrying numerical error values allowing detailed analyses.
The milled group displayed a mean of fit discrepancies of 42.20 m (SD 3.04 m), while the laser-sintered group showed a mean of 42.24 m fit discrepancies (SD 2.94 m). Thus, a small difference of 0.04 m between the two groups was detected.
The evaluated manufacturing systems can be used in dental practice as a small and insignificant discrepancy of fit between the two manufacturing methods was detected.
本研究旨在调查计算机辅助设计/计算机辅助制造（CAD/CAM）程序对金属基底冠整体适合性的影响。
用超硬石膏为右上颌第一磨牙制作全冠预备体的标准化模型。使用Identica蓝光扫描仪对模型进行数字化处理，并使用CAD软件设计基底冠结构。雷尼绍公司根据软件生成的文件制造了10个铣削试件和10个激光烧结试件。所有20个基底冠均通过Identica扫描仪进行数字化处理，并将数据与预备全冠的原始制造前数据文件进行叠加。使用几何建模库（GML）软件包，将适合性差异以彩色地图的形式显示，展示三维空间中的差异。每张地图由数千个带有数值误差值的数据点组成，便于进行详细分析。
铣削组的平均适合性差异为42.20μm（标准差3.04μm），而激光烧结组的平均适合性差异为42.24μm（标准差2.94μm）。因此，检测到两组之间存在0.04μm的微小差异。
由于检测到两种制造方法之间的适合性差异微小且不显著，因此所评估的制造系统可用于牙科临床实践。
