Monitoring the caries process. Optical methods for clinical diagnosis and quantification of enamel caries

Early detection of a caries lesion would enable the dentist, by using effective prophylactic measures, to enhance remineralization and conservation of the tooth substance rather than restoration of the dentition. The presently-used diagnostic methods of detecting early lesions require visual observation. Reflected light is used to detect changes in color, texture, and translucency of the tooth substance. Attempts to improve the traditional methods or to develop new ones have been numerous. For clinical use, only 2 quantitative methods are presently available: (i) a method based on the scattering of light by enamel crystals in relation to their surrounding environment, and (ii) a method that uses visible laser light within the blue-green region as the light source to excite the autofluorescence of enamel. The possibilities and limitations of these methods are evaluated, and clinical applications are presented and discussed.