Haptics-based Micro-deformation Design Techniques For Dental Model Surface

The teeth surface deformation technology based on haptics interaction system becomes more and more attention in the field of prosthodontics. Using the technology doctors can complete the restoration of teeth easily and efficiently. The three-dimensional surface information of each patient's teeth is sole in the process of teeth surface deformation, so we must adjust the teeth surface in order to match its adjacent teeth and opposite teeth after doctors found corresponding standard teeth in the standard crown database. This article researches on the micro-deformation techniques for three-dimensional tooth surface using force haptic interaction device PHANTOM Omni made in SensAble combined on the actual situation of oral clinical application. The main research content and innovation are as follows:Analysis of the operational mechanism of device and establishes the design platform based on the force haptic interaction device PHANTOM Omni. Complete the overall deformation for the teeth surfaces using proportional transformation method. Propose the local deformation based on the N rings neighborhood algorithm, and achieve the design of local deformation by deformation region. Research on the Laplacian smoothing method and Loop subdivision method based on the triangle area for the unusual triangle pieces and complete mesh adjusting work after deformation.Research on the regional deformation based on the implicit surface algorithm on the basis of the short comings of local deformation. Specify the control point of the deformation original using OpenGL and N ring neighbor algorithm and establish implicit surface equation based on the radial basis function and achieve the location for target points by manipulating interactive devices. At last, project remaining mesh vertices onto the implicit surface using Newton's iterative method and generate the desired mesh.Achieve the design software development of teeth surface micro-deformation based on the force haptic interactive devices in the VC++2003 and OpenGL graphics library on the basis of the above studies. The entire design system is divided into three modules: the overall deformation, local deformation, regional deformation and be applied in the prosthodontics system and make a good result.