This paper presents the various applications of near-infrared light transillumination (NILT) in dentistry. Untreated dental caries is considered the most prevalent health condition affecting both children and adults worldwide. Increased awareness and a paradigm shift toward utilization of minimally invasive treatment procedures and nonionizing radiation led to the discovery of newer techniques for screening and early diagnosis of demineralized lesions. Demineralized lesions detected early can be treated with minimally invasive treatment procedures such as the usage of fluoridated dentifrice to encourage remineralization and resin infiltration to arrest caries progression. NILT procedure involves noninvasive, nonionizing radiation and helps in the identification of early demineralized lesions using light transillumination. At near-infrared wavelengths, the enamel appears translucent and helps in visualizing and detecting demineralized lesions when long-wave light transilluminated against the tooth surface. The wavelength in the range of 1310 nm is considered best for the transillumination of lesions. This technique has been proven to be successful in the detection of carious and demineralized lesions. NILT can be used as a screening tool for the early detection of demineralized lesions and can be considered as an adjunct to bitewing radiographs. It can be advantageous in screening pregnant, growing adolescent patients and in cases where multiple follow-ups are needed and ionizing radiation must be avoided.
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