In dental treatment, dental computer-aided design (CAD) and computer-aided manufacturing (CAM) systems have been introduced to assist dental technicians in fabricating dental prostheses. The fabrication process is as follows. Before fabrication, the dentist removes dental caries from a patient’s tooth and prepares an abutment tooth. Next the shape of the abutment tooth is scanned by a 3-D scanner to generate a 3-D model of the abutment tooth on a computer. Then, using a CAD system, the dental technician designs a dental prosthesis that fits the abutment tooth. Finally, the dental prosthesis is fabricated using a CAM system and a machine tool. In the process of using the CAD/CAM systems, the shapes of abutment teeth sometimes cause problems such as the impossibility of fabricating a dental prosthesis. The purpose of this study was to develop a system that evaluates the appropriateness for the abutment teeth. Using 3-D models of abutment teeth, the system can examine: (1)whether a prosthesis can be fabricated using the machine tool ; and(2)whether there are undercuts on the abutment tooth. Using the system, we evaluated the abutment teeth prepared by students in our dental training school. The evaluation by the system was compared with the assessment by a teacher. The system execution and the comparison showed that the system can be used for evaluating abutment teeth.