What dental bleaching techniques are used?

There are three approaches to dental bleaching:

• Professional in-office bleaching generally uses gel, applied directly on the teeth, that contains or releases more than 25% hydrogen peroxide. These treatments last from 30 minutes to about one hour. In some cases, the activation is accelerated by heat or by light. The soft tissues must be protected.
• Professional home bleaching uses a gel with a relatively low concentration of H2O2, and specifically less than 6%. The gel is applied on the teeth using personalised trays made by the office and worn during the night for at least 2 weeks.
• In the European Union the products freely sold to consumers can contain only very low levels of a bleaching agent (gel that contains or releases less than 0.1% hydrogen peroxide) and are self-applied on the teeth using rubber trays, strips and varnishes. They must be applied two times a day for at least 2 weeks.