Optical characteristics of three tissue layers, namely of enamel, dentin, and pulp, are compiled over the wavelength range from the visible to the near infrared on the base of available publications and own calculations. These characteristics were used to analytically simulate the diffuse reflectance of multilayered tooth tissue (usually measured by an integrating sphere) and the distributions of the fluence rate over tooth depth. The light penetration depth is computed to be on the order of 2 mm. The obtained results can be useful to design various optical methods to noninvasively diagnose tooth conditions.