Research On Dental Aesthetics Restoration System Based On Two-dimensional Pictures And Three-dimensional Optical Scanning Data

With the development of economy,the attention in oral medicine has changed from helping people cope with the pain to improving people's quality of life.For example,patients are not only satisfied with the restoration of basic chewing function,but also pay more attention to the beauty and appearance of their restored teeth.However,aesthetics is highly subjective,and the traditional methods of making restorations are inefficient and cumbersome,which can no longer meet the needs.The application of digital technology provides great possibility and convenience for the realization of patients' personalized requirements.This paper researches on the method of prosthodontic esthestics based on twodimensional pictures and three-dimensional optical scanning data.This paper proposed a semi-automatic method of constructing realistic teeth model based on multi-feature 2d-3d registration,which accurately mapped multiple intraoral images onto the 3D teeth model to obtain the dentition model with real image texture.Firstly,we use optical scanner to obtain a triangular mesh model of dentition,then take three intraoral pictures of patients with a SLR camera,which include right-side image,front-side image and left-side image.Secondly,based on the points and local contour features of a single aperture,a single objective optimization algorithm is used to calculate the projection attitude of the camera corresponding to the aperture.Furthermore,according to the attitude of the camera,the preliminary projection texture mapping was conducted to find the location of texture juncture.Finally,the images on both sides of the texture joints were fused to eliminate the juncture on the 3d teeth mold with the principle of image pyramid.This paper also proposed a method of tooth shape beautification based on the feature line of 2d beautiful teeth,and the 3d model of teeth can be reconstructed with the constraint of 2d image of beautiful teeth.First of all,the smiling face photos of patient and the positive image in the mouth were taken,and the teeth image satisfactory to the patient was designed by using the two-dimensional dental beautification system,then we extract the tooth contour,and the pixel coordinates of the contour were converted to the vertex coordinates in the three-dimensional space.Secondly,obtain the contour of the to-be repaired 3d teeth model.Based on this contour,the 3d teeth model to be repaired is divided into active deformation zone,passive deformation zone and fixed zone.Next,the 2d tooth contour after aesthetic repair is matched with the 3d teeth model contour to be repaired by vertex matching,and the target position coordinates of each vertex in the active deformation area are calculated.Then,the grid deformation algorithm based on Laplace operator is used to smooth the deformation.Finally,the deformed 3d teeth model is meshed and smoothed to obtain the 3d teeth model after doing aesthetic restoration.In this paper,we proposed a method of semi-automatically constructing realistic teeth model based on multi-feature 2d-3d registration,which can realize semiautomatic construction of realistic teeth model with a small amount of simple manual operation to obtain a better simulation effect.In the future,the simulation effect of dental model can be improved only by simple manual operation in prosthodontic esthestics and other dental medical auxiliary systems.With the tooth shape beautification method based on the two-dimensional tooth feature line presented in this paper,the semi-automatic restoration of the aesthetic defects of the front teeth was realized by using the two-dimensional tooth feature line,and the dental model of aesthetic restoration was obtained.The prosthesis is printed by 3D printing technology,which can greatly improve the implementation efficiency of medical program and provide the possibility for patients' personalized aesthetic repair needs.