The aim of this study was to investigate the effects of high refractive index liquids on PS-OCT imaging of dental enamel. Several biocompatible agents such as propylene glycol and glycerol that have been proposed or utilized for soft tissue OCT experiments (skin and GI mucosa) were applied to the occlusal surfaces of sound and carious teeth. This study determined that the application of high refractive index liquids increased penetration depth in sound enamel to a greater degree than dried or water moistened samples. The results also demonstrated that image contrast between sound and carious enamel is dependent on the viscosity of the liquid and the degree of porosity of the carious lesion. The use of liquid agents with different viscositites in PS-OCT imaging may help determine the severity and depth of caries lesions in the occlusal pits and fissures.