Image Detection And Statistical Analysis Of Internal Defects Of Porcelain Fused Teeth

As people's overall living standards are being raised,changes in eating habits,especially the increase in high sugar,exquisite food intake cause more and more common oral health problems of people.Due to periodontitis,caries,trauma and other causes of tooth loss is a common clinical manifestation of oral diseases,its severity increased with age.At present,as one of the main options for oral rehabilitation,porcelain teeth are ideal prosthesis for tooth defect or loss,more and more people choose wear porcelain teeth to repair the oral problems.Thus,producing high-quality porcelain teeth to meet people's needs is particularly urgent.At present the process of making porcelain teeth applies porcelain fused to metal technique.Through the printing mold,wax type,embedding,casting,porcelain,bonding and a series of process to complete.But in the production process bubbles,pores,pinholes and other defects usually occur,which greatly affect the quality of porcelain teeth and thus affect the porcelain teeth life.In this background,this paper analyses the internal defects of porcelain teeth by studying the MicroCT images of porcelain teeth and does statistical analysis on the distribution of defects in porcelain teeth.It provides a theoretical guidance for the production process of porcelain teeth,thus providing strong theoretical support for the problems that exist in the industrial production process.This paper was supported by the Guangdong Provincial High Performance Computing Key Laboratory Open Project(Project No.TH1528).The works of this paper are as follows:Firstly,this paper introduces the background and significance of the study of porcelain dental defects based on MicroCT image.The research status of MicroCT image statistical analysis is analyzed,and the research work and main research results are introduced.Secondly,this paper elaborates the theory of image processing.The overall framework of image analysis based on MicroCT image is presented.The image preprocessing of the MicroCT image of the porcelain teeth is mainly composed of the following: gray image transformation,spatial filtering and two methods are used to enhance the image enhancement,and the image enhancement effect is compared.The enhanced image samplesare binarized by Otsu binarization algorithm,Niblack binarization algorithm and optimal threshold method.Then compare the advantages and disadvantages of the three methods and choose the best method.Thirdly,this paper describes the basic theory of porcelain dental defect detection statistical analysis.In the case where the distribution of the variables is unknown,the distribution of the variables is estimated from the sample data.The methods and steps of parameter estimation and hypothesis testing are introduced,and the commonly used distributions and their probability density functions are also introduced.Fourthly,this paper introduces the specific operation flow of statistical analysis of porcelain teeth internal defects.Combined with the principle of mathematical statistics analysis,the area of defects of defective porcelain teeth,the centroid coordinates of defects,the roundness of defects,and the shape of defects are calculated.Secondly,the type of the probability density distribution function is determined by drawing the frequency histogram of the defect area,the centroid coordinates,the number of the roundness of defects and the number of polygons of the defect.Thirdly,we conducted parameters estimation on the sample data to deduce and presume the distribution of the defects.Fourth,the hypothesis of the distribution were tested to finally determine the distribution of defect area and centroid coordinates.This paper focus on the number of triangles,quadrilateral and pentagons defects in the process of statistical analysis of polygons,and the steps of defect statistical analysis are expounded in detail.The experimental results show that the defect area of exponential distribution,that large area defect is more;the centroid coordinates obey the normal distribution,indicating the distribution of internal defects of porcelain teeth and porcelain teeth are mostly concentrated in the edge transition arc;circular defects of normal distribution,indicating the internal defects of porcelain teeth is mainly due to the production of bubbles in porcelain teeth due to the defects,pores;the quadrilateral number obeys the normal distribution,indicating that the internal defects of the porcelain teeth were partly due to the residual stress in the prothetic porcelain teeth,and the different parts of the contraction.The study of MicroCT images of internal defects of porcelain teeth not only can get the position of defects in the productionprocess accurately,but also can get the regularity through the defect analysis to provide effective theoretical guidance in the process of improving the porcelain tooth production process.