Provided are methods of detecting tooth stain prevention and/or removal comprising the steps of providing pellicle-coated hydroxyapatite particles, contacting the particles with a first solution and then a second solution, wherein the first solution is either a test solution or a stain solution and the second solution is the other of said test solution or stain solution, separating from the resulting particles a liquid comprising stain introduced in the contacting step b), and measuring the UV-Vis absorbance of the separated liquid to determine the amount of stain in the liquid.
