The Crown Shape Of Three-dimensional Optical Measurement And Modeling Methods To Establish And Veneer, Crown Cad

High resolution 3-D surface measurement of teeth is a key to dental CAD-CAM systems. There are several kinds of measurement methods, but no one can meet all requirements for denture process. This thesis represents the application of an optical method to obtain the 3-D parameters of teeth surfaces for the purpose of design veneer and artificial crown by computer-aided design.There are nine chapters in this thesis.Chapter 1 gives an introduction of the various dental CAD-CAM systems and the 3-D measurement methods among the dental CAD-CAM system.Chapter 2 explains the principle of extracting 3-D information from the deformed grating pattern, including Fourier transform profilometry and an algorithm to demodulate deformed grating pattern, and introduces the concept of the phase unwrapping.Chapter 3 describes the 3-D measuring setup and software. The setup consists of a grating projection system and CCD imaging system. All lens system are special designed for measurement of teeth with high resolution. The software that support the setup to complete image grabbing, image computing, image managing and phase unwrapping are designed and programmed by the authors.Chapter 4 and 5 analyze the errors in the measuring system and introduce a simulation method that is designed to compute phase errors numerically, and describe an experiment for determination of the phase-height relation.Chapter 6 represents the procedure of the measurement of tooth crowns with our 3-D measuring setup, and the three-dimensional surface maps of crowns.Chapter 7 introduces the principles and methods about teeth crown measurement modeling according to the three- dimensional surface maps of crown, presents the...