In Pursuit of an Optimum Optical Imaging Technology for Early Detection of Dental Caries

Clinical caries detection techniques, such as radiographs, are not sensitive to detect and monitor the progression of caries at early stages. In recent years, several optics-based imaging modalities have been proposed for early detection of caries. In this thesis, we report on a systemic comparative study on the performances of optical coherence tomography and thermophotonic lock-in imaging (TPLI) as early caries detection imaging modalities based on light scattering and absorption, respectively. Through controlled demineralization on extracted human teeth, our results suggest that TPLI provides better sensitivity and detection threshold in detecting early stages of caries. The outcome justifies the need for a light-absorption based imaging modality to produce depth-resolved images. Therefore, preliminary imaging studies on a 3-D imaging platform known as a Truncated-Correlation Photothermal Coherence Tomography (TC-PCT) system was conducted to achieve optimal diagnostic yield. The results demonstrate that TC-PCT can detect early caries with significant enhancement in depth-resolution.