Dental bleaching, also known as tooth whitening and swabbing, is a common procedure in general dentistry but most especially in the field of cosmetic dentistry. According to the FDA, whitening restores natural tooth color and bleaching whitens beyond the natural color. There are many methods available, such as brushing, bleaching strips, bleaching pen, bleaching gel, laser bleaching, natural bleaching, and swabbing.
Bleaching methods use carbamide peroxide which reacts with water to form hydrogen peroxide. Carbamide peroxide has about a third of the strength of hydrogen peroxide. This means that a 15% solution of carbamide peroxide is the rough equivalent of a 5% solution of hydrogen peroxide. The peroxide oxidizing agent penetrates the porosities in the rod-like crystal structure of enamel and bleaches stain deposits in the dentin. Power bleaching uses light energy to accelerate the process of bleaching in a dental office. A new bleaching agent is 6-phthalimido peroxy hexanoic acid (PAP).
In-office bleaching procedures generally use a light-cured protective layer that is carefully painted on the gums and papilla (the tips of the gums between the teeth) to reduce the risk of chemical burns to the soft tissues. The bleaching agent is either carbamide peroxide, which breaks down in the mouth to form hydrogen peroxide, or hydrogen peroxide itself. The bleaching gel typically contains between 10% and 44% carbamide peroxide, which is roughly equivalent to a 3% to 16% hydrogen peroxide concentration.