There are many techniques used to whiten a tooth that has changed color. If the change in the coloration is due to some problem with the dental pulp of tooth that has undergone endodontic treatment, internal bleaching is performed. Internal bleaching acts on the interior of the tooth where the pulp is located.
When the tooth still maintains its vitality, or the change in color is generalized, the bleaching is carried out on the external surface. Substances based on peroxides are usually used for this purpose, on stimulation by light or heat, these substances release nascent oxygen. The techniques vary in the concentration of the peroxide, and the patient can perform them at home or in the dental clinic.