Early detection, monitoring and remineralization repair of enamel lesions are top research priorities in the modern dentistry focusing on minimal intervention concept for caries management. We investigate the use of swept-source optical coherence tomography system (SS-OCT) without polarization-sensing at 1319 nm wavelength developed for clinical dentistry (Dental OCT System Prototype 2, Panasonic Healthcare Co., Ltd., Japan) in quantitative assessment of artificial enamel lesions and their remineralization. Bovine enamel blocks were subjected to demineralization to create subsurface lesions approximately 130 μm in depth over 2 weeks, and subjected to remineralization in solution containing bioavailable calcium and 1ppm fluoride at pH 6.5 for 2 weeks. Cross-sectional images of sound, demineralized and remineralized specimens were captured under hydrated conditions by the OCT. Finally, the specimens were cut into sections for nanoindentation to measure hardness through the lesion under 2mN load. Reflectivity had increased with demineralization. OCT images of lesions showed a boundary closely suggesting the lesion depth that gradually progressed with demineralization time. After remineralization, the boundary depth gradually decreased and nanoindentation showed over 60% average hardness recovery rate. A significant negative correlation was found between the slope power-law regression as a measure of attenuation and overall nanohardness for a range of data covering sound, demineralized and remineralized areas. In conclusion, OCT could provide clear images of early enamel lesion extent and signal attenuation could indicate its severity and recovery. Clinical data of natural lesions obtained using Dental OCT and analyzed by this approach will also be presented. Study supported by GCOE IRCMSTBD and NCGG.