Research On The Key Technologies In Computer-Aided Dental Design

This dissertation deals with the key technologies in computer-aided dental design, including the feature-based modeling of standard tooth, the feature-based design of crown, the feature-based design of fixed bridge and the optimum design for bridge geometry. The following contributions have been made.Based on both dental anatomy and CAD theory, dental features for tooth modeling are summarized, and the feature-based modeling of the standard tooth is presented as follows. According to dental features, the coordinates of teeth models are firstly established, and the feature points, feature curves and feature surface patches are utilized to construct the different features. At last, the standard prosthetic models are formulated through topologically connecting all the constructed features by Nurbs surfaces. These models have the two functions of possessing the same features with the patient's missing teeth, and the local adjustability with the feature points, the feature curves and the feature patches.For the purpose of the quick and accurate design of dental prostheses, a newly developed CAD approach for the feature-based design of the prosthetic crown is investigated. In this approach, the global and occlusal feature curves are proposed considering the individual patient's original information. According to these curves and other restrictions, the features of the corresponding standard prosthetic models are adjusted to meet the fit of the global size and occlusal surface. Consequently, the close and continuous profiles of the crowns are generated. Using this design, a posterior prosthesis is successfully manufactured in the machining process, testifying the effectiveness of the approach.The feature-based design of fixed bridge is carried out by applying the feature-based design of crown technology. In addition, an effective approach is presented to create the connector through knuckling the contact areas. The result shows that the clinical requirement for the connector's shape and position is satisfied, and the load bearing capabilities of the retainers are enhanced.The influences of the variations of the connectors geometries having on the...