Accuracy of Kubelka-Munk reflectance theory applied to human dentin and enamel

The Kubelka-Munk (K-M) theory provides a reflectance model for translucent materials placed on backings of different colors. We hypothesize that Kubel ka-Munk (K-M) theoretical diffuse reflectance spectra of dentin and enamel are in good agreement with observed diffuse reflectance. The aim of this st udy was to measure the reflectance of enamel and dentin specimens and to co mpare the measured values of reflectance with K-M theoretical values. Disc- shaped specimens of enamel, dentin, and enamel/dentin were prepared from ex tracted teeth. Diffuse reflectance spectra were measured on three backings by means of a reflectance spectrophotometer over every wavelength (lambda) from 400 to 700 nm at three thicknesses. The measured reflectance values we re fit by non-linear regression to corrected K-M theory. The low value of t he reported errors associated with the application of K-M theory illustrate d that the theoretical diffuse reflectance spectra of dentin and enamel are in good agreement with the observed diffuse reflectance.