We present a case of internal clarification of an adult tusk that has a strong coloration of dark brown color very obvious. These color changes in teeth to which dental pulp has been extracted are due to the absorption of polpa materials and the own endodontic that penetrate the hard tissues and dye the dentin. Fortunately, the same fact of having practiced the endodontic allows the placement of the clearing agents within the tooth. Once closed with a provisional seal, they generate pure oxygen, this creates a pressure that causes this oxygen to diffuse through the dentin by destroying the molecules of the darkening agents. The process is fast and in a few days we recover the lost coloration with a very satisfactory and very little reversible result.