Near-Infrared Light Transillumination

Abstract

Near-infrared light transillumination (NILT) uses near-infrared light to visualize enamel and dentin caries lesions in molars and premolars. An intraoral camera emits near-infrared light by two light emission windows, and the image of the transilluminated tooth is captured with a CCD sensor over the occlusal surface. The altered structure of demineralized enamel with larger numbers of pores and interprismatic water content causes an increase in light scattering and absorption and therefore appears less transparent than sound enamel. The strength of the method is in the early detection of enamel lesions on proximal sites, it is possible to describe the extension of the lesion much more precisely in relation to the dentin-enamel junction. The method can also be used for occlusal caries detection.