History, safety, and effectiveness of current bleaching techniques and applications of the nightguard vital bleaching technique.

This article reviews the literature on the use of hydrogen peroxide in three professionally administered bleaching techniques from historical, technique, and safety viewpoints. Safety over time, absolute safety, and relative safety of nonvital bleaching, in-office vital bleaching, nightguard vital bleaching, and over-the-counter bleaching kits are compared. The advantages and disadvantages of different bleaching options, as well as indications for individual or combined use of the techniques, are discussed. In addition, specific indications for the use of the nightguard vital bleaching technique are presented.