What is teeth whitening (bleaching)?

Teeth whitening, also called bleaching, is a cosmetic procedure that lightens tooth color using chemical agents rather than abrasive polishing. The active ingredient in professional whitening is a peroxide compound, typically hydrogen peroxide or carbamide peroxide, which penetrates the tooth surface to break down stains and discoloration.

Professional whitening takes two main forms. In-office whitening, performed at a dental clinic, applies a higher-concentration gel directly to teeth and often uses a special light to accelerate results. This method produces visible brightening in a single appointment, usually one to two shades lighter. Take-home whitening involves custom-fitted trays supplied by a dentist with lower-concentration gel for use over several days or weeks at the patient's own pace.

Teeth whitening differs fundamentally from whitening toothpaste, which contains only mild abrasives and polishing agents that remove surface stains but cannot change the underlying tooth color. Bleaching actually alters the tooth structure itself through chemical action, delivering more dramatic and lasting results.

Results vary based on the starting shade, lifestyle, and adherence to any aftercare instructions. Staining from coffee, tea, or tobacco typically responds well to treatment. Yellowed teeth from age often show improvement, though heavily discolored or greyish teeth may require more intensive sessions. Effects are not permanent, as teeth gradually reabsorb stains over months or years depending on diet and habits.

Patients seeking professional whitening should consult a dentist to assess candidacy, discuss realistic outcomes, and explore options at cosmetic dentistry providers in their area.