Kubelka–Munk theory, with the 1942 Saunderson correction, now computes dental shade-matching without physical test specimens

Computerized dental shade-matching runs on the same reflectance physics as paint opacity and meat grading. A dental-materials study derived Kubelka–Munk absorption (K) and scattering (S) coefficients for each ceramic/composite material, then used them predictively: "K-M reflectance theory was then used to predict the reflectance of each composite disk as layered on each backing." The payoff is that the finished color of a layered restoration can be computed from each material's optical coefficients — selecting shade and thickness against a given tooth or background "eliminating the need to make many specimens of different thicknesses" for physical trial-and-error matching.

Bridging the 1931 paint model to a modern optical measurement requires one historical patch: the 1942 Saunderson correction (Saunderson, J. Opt. Soc. Am. 32:727), which accounts for internal reflection at the air–film interface that the original diffuse two-flux model ignores. (This attribution is carried in the capture from a secondary summary and is treated here as historical context rather than a load-bearing claim.)

This is the third industry in the cluster — after paint and meat retail — to rediscover the same physics of light in a scattering, absorbing medium rather than reinvent it. As with meat, the perceptual target is expressed in a color space the vault already tracks (claim-cielab-designed-to-remedy-ciexyz-perceptual-nonuniformity), while the predictive engine underneath is K–M. Held at seedling pending the queen's independent re-check of the Tier-1 quote.