在複雜曲面的牙冠加工中,傳統三軸加工遇到銑削內凹區域時,必須不斷調整進刀方向以進行切削,但還是無法加工出完整的倒凹區域,導致牙冠表面及接合面精度無法達成設計需求。因此本研究發展一套新的五軸刀具路徑產生法則,以三角網格模型(STL, Stereo Lithography)為基礎,混合C-Space與向心法快速搜尋刀具軸向,建立一套自動化路徑生成的電腦輔助製造(Computer-aided manufacturing, CAM)系統應用於牙冠加工。傳統三軸加工對於外型複雜的牙齒已不敷使用,對於牙齒倒凹部分無法達成加工需求,本論文利用STL為基礎產生五軸刀具路徑,在規劃基礎刀具路徑前,對待處理的工件模型進行轉正以減少刀具傾角變化,利用Z-Level產生等高的刀具路徑,最後利用C-Space與向心法混合規劃刀具軸向,完成一套應用於牙冠加工的五軸電腦輔助製造系統。 In a dental CAD/CAM system, when milling the concave area of the inside surface of a tooth crown, the machining direction of the tool has to be adjusted constantly in order to avoid gauging or over-cutting. For some under-cut area, the tool also needs to be tilted to machine the under-cut area, otherwise the crown may not seat properly on the abutment due to interference. The purpose of this research is to establish a new 5-axis tool path generation algorithm. Based on the triangular mesh model, a hybrid C-Space and Centroid method is proposed to quickly search the proper tool axis directions. The establishment of a computer-aided manufacturing (CAM) system for automatic tool-path generation is applied to dental crown machining. The traditional 3-axis machining, when applied to complex surface milling of a dental crown, has never been satisfactory. It cannot produce the desired smooth and gauging free surface. In this thesis, we use the STL format to generate a 5-axis tool-path. First, the orientation of the workpiece will be corrected to reduce tool inclination changes. Secondly, the system generates the tool-path by the Z-Level algorithm. Finally, we use the proposed hybrid C-Space and Centripetal method to determine the tool axis. The integration of the above methods makes the automatic tool-path generation of the crown surface possible, which is very important for the automation of a dental CAD/CAM system.