The Feature Modeling Technology In Dental CAD/CAM System

The state of art of the feature modeling technologies in dental CAD/CAMsystem is developed in terms of design , aiming to develop a dental CAD/CAMsystem with the autonomic intellectual property. The following creative work hasbeen completed:1. According to the research background, the feature modeling, including database establishing, global feature modeling, occlusal feature modeling and other relative factor designing, is proposed with the characteristics such as simple and high precision.2. Virtual models of standard crown surfaces are created on the basis of the data measured by a 3D touching scanner with the result that the database of the standard 3D tooth crowns is obtained. The virtual crowns in database are expressed as cloud, network and surface so as to be adjusted conveniently.3. Four global feature curves are proposed based on the information given by the feature of virtual neighbor teeth. According to these curves and the feature contact areas of neighbor teeth, the global size of the absent tooth is obtained. These technology aids the design of denture with high precision.4. Two occlusal feature curves are proposed based on the information given by the feature on the occlusal working surface of antagonistic teeth. According to these curves and the feature on occlusal surface of mirror side tooth, the occlusal surface of the virtual crown is adjusted. By simulating occlusion, the intervention areas among virtual crown and antagonist teeth are identified and adjusted. As a result, the occlusal feature modeling technology as a key technology on the reparation of occlusal surface is available.5. Taking occlusal force, retention, insertion into considering, adjustments of the abutment, crown thickness, insertion path are put forward. And finally a continuous surface is formed by connecting the crown and butment surfaces so II天津大学硕士学位论文 as to provide basis for dental CAM. The achievements stated in this dissertation lay a foundation for the design of adental CAD/CAM system.