This year is approximately the fifth year of controlled bleaching of vital teeth administered by the patient, and this practice still generates a great deal of discussion by the American Dental Association, the US Food and Drug Administration, the media, and general practitioners. The placement of a plastic carrier intraorally to hold a carbamide peroxide gel in the mouth is referred to as passive bleaching or dentist-prescribed home bleaching. This article reviews the past year's research, which contains many opposing opinions in both in vitro and in vivo studies with respect to the effect of carbamide peroxide on the hard and soft tissues when they come into contact with this agent for various lengths of time. Above all, the question of safety still arises, although few if any adverse effects have been reported with the use of dentist-prescribed, patient-applied home bleaching. Five years of nonproblematic treatment for millions of patients leads many dentists to believe that this technique, when controlled by the dentist, serves the public well.