Research And Application On The Key Technologies For The Feature-Based Standard Crown Database

With people’s requirement of oral health has been heightened, the CAD/CAM technologies arewidely applied to dental medical treatment. The standard tooth crown database is one of the mostimportant and fundamental part of dental CAD/CAM system, providing effective support of modelsfor dental restoration design, and the efficiency for dental restoration design is improved. Combinedwith the actual demands of dental clinic, choosing the dental restoration (crown) as the object of study,relevant theories, design procedures and key technologies are studied deeply in the dissertation and afeature-based standard crown database is developed. The main contents and achievements are asfollows:(1) The construction process of the mean model and the calibration of the feature points arestudied. After analyzing the basic concept and algorithm of registration, a new registration methodwhich combined with rigid registration and non-rigid registration using FFD based on B spline is putforward. The Hausdorff distance (HD) between the original model and the registration model iscomputed to evaluate the performance of the point-to-point correspondence. At last, the features ofcrown model are located by manual interaction.(2) The design technique of the tooth’s restoration based on the curves-driven is studied, and atooth shape design method based on skeleton-driven is proposed. According to the shape of the tooth,an approximate skeleton curve of the model is sketched. Then, the relationship is established betweenframes and points of model. The global or local deformation is generated based on the relationship bydriving the skeleton curve. The deformation design is finished.(3) The construction technology of the standard tooth crown database is researched. According tothe primary steps of database design, preliminary design, logical structure design, physical structuredesign are implemented. Research and design of location and deformation features are put anemphasis on. A new query algorithm based on the binary tree is proposed, and a suitable interface(XMLParse) is designed for dental software. Thus, the module of feature-based standard crowndatabase is built.