Development of the training system for the tooth preparation using a personal computer

最近，CAD/CAM技术已被引入牙科领域，预计将减少牙科实验室程序。该技术不仅包括蜡模和铸造被计算机辅助技术取代的技术方面，而且还包括消除印模材料、石头、蜡和包埋料等中间材料的环境方面。此外，我们还期望通过计算机辅助来控制假体的质量。此外，我们的目标是将这项技术应用于教育，特别是在牙齿准备领域。我们已经开发了原始的CAD/CAM系统，在石头模型上自动制造陶瓷冠。在这项研究中，数字化的准确性在开发系统进行了评估。在CAD/CAM设备中，通过激光数字化仪制备简单标准化基台的模型并进行数字化。并与卡尔蔡司公司的UAA-CAA 850型三维精密接触式测头数字化仪进行了比较。的 ...更多信息 用激光位移计对基牙的断面进行数字化处理，结果表明，由于二次反射和多种噪声的影响，在图形上观察到了数据散射。最大散射为（]SY. ±-。[）600 μ m。在激光数字化仪中，对同一束激光组成四个接收器，以比较和选择合适的数据。然而，结果表明，我们需要提高数字化的准确性。我们开发了改进的CAD/CAM机器，其中用于数字化和加工的支撑部件是不同的，以消除无用的悬垂。由于位移计的光轴和滤波器特性的改进以及防止随机反射，即使在新机器中只安装了2个PSD传感器，数字化过程中的噪声也大幅降低。我们还开发了软件来表达数字化的基台在显示器上，学生可以了解他们准备的基台和主模型之间的差异。该CAD/CAM设备在教育领域具有广阔的应用前景。少

Recently CAD/CAM technology has been introduced in a dental field to be expected to reduce the dental laboratory procedure. This technology included not only the technical aspect where wax-up and casting is just replaced to computer assisted technology but also the environmental aspect to eliminate intermediate material such as impression material, stone, wax and investment. In addition, we expected to control the quality of prostheses by aiding computer. Furthermore, we aimed to apply this technology to education especially in the field of tooth preparation. We already developed the original CAD/CAM system to fabricate ceramic crowns automatically on stone models. In this study digitizing accuracy in the develop system was evaluated. The model for the simple standardized abutment was prepared and digitized by a laser digitizer in the CAD/CAM machine. Digitized data was compared with those digitized by three dimensional precision touching probe digitizer (UAA-CAA 850, Karl Zeiss). The … More sectioned surface of the abutment digitized by the laser displacemeter in the machine indicated the data scattering was observed on the diagram that was affected by the secondary reflection and several noise. Maximum scattering was (]SY.+-。[)600mum. Four receptors were composed for one laser beam in the laser digitizer to compare and select the suitable data. However, the result suggested we need to improve ccuracy of digitizing. We developed the modified CAD/CAM machine where the supporting parts for digitizing and machining were different to eliminate useless overhang. Noise during digitizing reduced drastically in the new machine because of the improvement of the light axis of the displacemeter and filter properties and the prevention of random reflection even if only 2 PSD sensors were fixed in the new machine. We also develop the software to express the digitized abutment on the monitor where students could understand the difference between their prepared abutment and the master model. We concluded the developed CAD/CAM device was expecting in the field of education in the future. Less