Internal bleaching of severe tetracycline discolorations: four-year clinical evaluation.

Two hundred fifty-eight teeth severely discolored by tetracycline were treated with an internal bleaching technique. Endodontic treatment was required in all teeth before the walking bleaching procedure could be undertaken. Four years of clinical and radiographic evaluation revealed good esthetic results for all patients. Endodontic procedures were considered to be successful, and not one patient showed external cervical resorption after 4 years. This type of treatment is a valid alternative to porcelain laminate veneers for those teeth that exhibit severe tetracycline discoloration and in which the dental enamel and anatomic crown are intact.