Research On Method And System Development Of All Fiber Oral OCT

Based on Optical Coherence Tomography (OCT), this dissertation has developed the oral caries OCT detection system. The major study of this dissertation is using the OCT method to detect the caries by detecting the changes of the optical parameters caused by early demineralization. This method plays an important role for diagnosis the dental caries, particularly for the early diagnosis, control, treatment and preventiaon.This dissertation focuses on the basic theory of OCT, the system design, system experiments and application experiments, the major studies of the dissertation are: the analysis of the all-fiber OCT system's basic principle; the simulation of optical transmission characteristics of the teeth; design and development of all-fiber polarization insensitive OCT system; access to the one-dimensional, 2D and 3D OCT images of human teeth in vitro; design and development of the all-fiber polarization sensitive OCT system, polarization OCT images of the human teeth in vitro are initially obtained; the use of the OCT system for application experiments inclued of the measurement of the refractive index of human teeth in vitro and modeling of external experiments, in addition, the experiments obtaining the OCT images of dental caries and the restoration of teeth.The major innovation in the work:1. Design and development of the all-fiber polarization insensitive OCT system have been developed. The one-dimensional and two-dimensional OCT images of the normal and caries teeth are obtained. The one-dimensional and two-dimensional OCT images of the common oral restoration are also obtained. The rule shape data-based three-dimensional surface model algorithm has been developed and models for the teeth. The three-dimensional reconstructions of OCT images of the human teeth in vitro are obtained.2. This dissertation applies the OCT technology to detect early dental caries and studies the method of detecting the early dental caries using OCT. The experimenal research of the external model that simulates the caries articially for the human teeth in vitro is illustrated. Based on OCT method, the refractive indexes of the human enamel, dentin and cementum are measured. In addition, the refractive index distribution along the scan direction of the human teeth in vitro is obtained.3. Birefringence of the teeth and fiber are analysed and modeled. The all-fiber polarization sensitive OCT system has been developed; the polarization OCT images of the human teeth in vitro are initially obtained.4. The layered model to character the optical transmission portery of the organization is illustrated. The structural characteristics of enamel and dentin are described and in accordance with their optical parameters, the distribution of light on and below the enamel and dentin surface are simulated.