Laser light-induced fluorescence, based on the phenomenon that caries lesions, plaque, and microorganisms all contain fluorescent substances that can be distinguished from each other and the autofluorescence of enamel and dentine. An example of this type of product is the Canary System™.
Quantitative laser-light induced fluorescence, such as the Inspektor QLF™, which can quantitatively detect the difference in fluorescence between sound tissue and that of a caries lesion.
DIAGNOdent, which uses red light to induce fluorescence and handy tools/probes, such as the DIAGNOdentpen, which can fit into smaller spaces and fissures in occlusal and approximal surfaces of teeth to capture differences in fluorescence that could indicate a lesion.
Fiber-optic transillumination (FOTI) and the more sensitive digital imaging fiber-optic transillumination (DIFOTI), which are qualitative diagnostic methods by which teeth are transilluminated to detect shadows, which has been associated with the presence of carious lesions.