Research And Implementation Of Computer-Aided Color Matching System For Porcelain Teeth

Porcelain teeth have drawn the attention of dental experts since they have a similar color with natural teeth in recent years. How to make a porcelain tooth which has a high similarity with the natural tooth has always been active research subject for doctors and scientists alike. The goal of this research has been to select the tooth color properly. Specially trained dentists will select the most similar color model with the patient's teeth from the shade guides by means of the naked eye. This classical method is affected greatly by the surrounding light and visual diversities of a person. Therefore, researchers have proposed to help doctors to select the proper color by using Machine Vision techniques. Based on the previous probing and colorimetric algorithms, this article outlines a Computer-Aided porcelain tooth color matching system using C#. In this paper, the main achievements can be described as follows.(1) A system has been designed and implemented for real-time image acquisition and processing. Through a large market research, the author has configured a pre-processing and image acquisition system. After improvements, the device can avoid the effects of surrounding light, as a result its' application area has been extended.(2) Methods for segmenting teeth and image enhancement have been implemented. Based on the characteristics of teeth images, we have applied the threshold projection method on the tooth segmentation. As there are some reflection areas on the surface of a tooth, gray-level interpolation has been employed to minimize the impact of the reflecting light on the image analysis, so as to enhance the image recognition success rate.(3) Main features of teeth have been extracted from images. Based on the previous research of colorimetry, this article has adopted Principal Component Analysis (PCA) and Two Dimensional Principal Component Analysis (2DPCA) to achieve feature extraction, to acquire a feature projection space. This method makes a significant reduction of the calculational cost of the system(4) Classification of porcelain teeth has been achieved successfully. According to the analysis of previous simulation results of three classifiers, Support Vector Machine (SVM) has been selected. The classifier has achieved good classification results at accuracy of 70.2 %.(5) A real-time acquisition and test system of the tooth samples has been implemented. When combining the function of each module, this system would realize the tooth colorimetry system perfectly and collect valuable experimental results.(6) A case database has been designed and implemented. This system can provide the functions to show the database, add, modify and delete the corresponding information. It could facilitate the management of case information for doctors, so that to make the database management integrated and efficient.In addition, a sample database of Vitapan 3D-Master shade guide has been created. The experimental results show that the classifier has high color matching accuracy. The study of Computer-Aided Color Matching System on Dental Prostheses in this paper can play a good exploring and supporting role for dental experts.