Tooth bleaching can be categorized into vital and non-vital bleaching, depending on the condition of the tooth. Vital teeth are the teeth that have viable pulp.
Vital tooth bleaching
There are three fundamental approaches for bleaching vital teeth:
A high concentration of tooth-whitening agents (25–40% hydrogen peroxide) is used. It is a completely controlled procedure as the dentist can stop it when the desired shade/effect is achieved.
At-home or dentist-supervised night-guard bleaching
It basically involves the use of a low concentration of whitening agent (10–20% carbamide peroxide, which equals 3.5–6.5% hydrogen peroxide). This treatment is carried out by the patients themselves, but it should be supervised by dentists during recall visits. The bleaching gel is applied to the teeth through a custom-fabricated mouth guard worn at night for at least 2 weeks.
Over-the-counter (OTC) bleaching products
These are composed of a low concentration of whitening agent (3–6% hydrogen peroxide) and are self-applied to the teeth via gum shields, strips, or paint-on product formats. They are also available as whitening dentifrices, pre-fabricated trays, whitening strips, and toothpaste. They should be applied twice per day for up to 2 weeks.