New fabrication system of prostheses using numerically controlled electric discharge machining

将电火花加工技术应用于假肢的制造。电火花加工的三个使用领域被分类为辅助使用、直接制造冠和桥以及使用CAD/CAM工艺制造钛镀层。研究了数控冲压式和线切割式电火花加工在钛铸件上加工精密附件的方法，发现它们的应用是可行的。另一方面，利用新开发的激光数字化仪和铣床，研究了冲压式电火花加工电极的CAD/CAM加工方法。制备了具有体基台和冠状形状的石墨电极，并为冲压式电火花加工钛提供了材料。电极的磨损是一个问题，我们不得不多次更换电极以达到足够的精度。此外，还研究了利用新开发的数字化仪和铣床直接用CAD/CAM加工冠的方法。这些结果表明所研究的新技术在未来是有前途的。

Electric discharge machining (EDM) was applied in the fabrication of prostheses. The three areas of use of EDM are classified as supplementary use, direct fabrication of crowns and bridges and fabrication of titnium copings using a CAD/CAM process. Numerically controlled (NC) ram type and wire type EDM were investigated to fabricate precision attachments on titanium castings and these usages were found practical. On the other hand, fabrication of electrodes for the ram type EDM with a CAD/CAM process was investigated using a newly developed laser digitizer and milling machine. Graphite electroles with boty abutment and coronal shapes were fabricated and supplied for machining titanium using ram type EDM.The wear of electrodes was a problem and we had to change electrodes many times to achieve enough accuracy. Furthermore, fabrication of crowns directly with a CAD/CAM process was also investigated using newly developed digitizer and milling machine. These results indicated new technolagies investigated are promising in the future.