0935   The Accuracy of the CAD/CAM System for Fabricating Complete Dentures
M. KANAZAWA, Y. SATO, S. MINAKUCHI, K. OHYA, Y. KAIBA, and N. OHBAYASHI, Tokyo Medical & Dental University, Japan

Objectives: The process of fabricating complete dentures is very complicated. The fabrication of complete dentures using a computer aided design/ computer aided manufacturing (CAD/CAM) system can simplifies this process. The purpose of this study was to evaluate fabricating accuracy of a complete denture using the CAD/CAM system. Methods: The cone beam CT (Fine Cube, YOSHIDA Dental) was used to measure the artificial teeth (Real Crown and Endura Posterio, SHOFU Inc.), and the DICOM viewer (OsiriX, The OsiriX Foundation) processed the three-dimensional (3D) morphological data of the artificial teeth. After 3D complete denture image was structured based on the 3D date of the artificial teeth by 3D CAD software (CATIA, Dassault systemes), we factored out the artificial teeth and get the 3D denture base image. 3D CAM software (Mastercam, CNC software Inc.) programmed cutter path based on the 3D denture base image. The five axis computerized numerical control (CNC) machining center (VARIAXIS 200, Yamazaki Mazak Corporation) cut an acrylic resin block based on the cutter path, and fabricated an acrylic complete denture base. The artificial teeth were bonded to the cut denture base using the resin cement (Super Bond, Sun medical Co.,LTD. ). Three-dimensional digitizer (Atos, Gom International AG), that is flexible optical measuring machine based on the principle of triangulation, digitized the fabricated acrylic denture. We measured the fabricating accuracy comparing the master 3D complete denture image with the 3D data of the fabricated acrylic denture using interchanging 3D measuring software (Atos viewer). Results: The average deviations from the master 3D image were 0.5mm, 0.3mm and 0.5mm in palatal surface, mucosal surface and cervical area respectively. Conclusions: Although further improvements are needed in processing the denture image and cutting of interdental area, this study indicated that it is possible to fabricate a complete denture using the CAD/CAM system.