Caries Detection Methods Based on Changes in Optical Properties between Healthy and Carious Tissue

Figure 2

Light interactions with a tooth. How waves can interact with the dental hard tissue; (a) reflection, the wave rebounds; (b) scattering, the incident wave enters the tooth and changes direction. The photons then leave the tooth either as backscattering, where the photons leave through the surface by which they entered, or through another surface (scattering with diffuse transmission); (c) transmission, the wave is illuminated through the tooth and refracts on the surfaces; (d) absorption with heat production; (e) absorption with fluorescence. Most interactions of waves are a combination of these processes.