Dental bleaching, also known as tooth whitening, is a common procedure in dentistry. A child’s baby teeth are usually whiter than the adult teeth that follow. As a person ages the adult teeth often become darker due to changes in the mineral structure of the tooth, as the enamel becomes less porous.Teeth can also become stained by bacterial pigments, foodstuffs and tobacco. Certain antibiotic medications (like tetracycline) can also cause teeth stains or a reduction in the brilliance of the enamel.

There are many methods to whiten teeth: bleaching strips, bleaching pen, bleaching gel, laser bleaching, and natural bleaching. Traditionally, at-home whitening involves applying bleaching gel to the teeth using thin guard trays. At-home whitening can also be done by applying small strips that go over the front teeth. Oxidizing agents such as hydrogen peroxide or carbamide peroxide are used to lighten the shade of the tooth. 

Impressions are taken to make the bleaching trays for dental office bleaching solutions. The solutions are generally a higher percentage than the stripes bought at the drug store and hence work faster with more intensity. The strips are a more economically way to "try" bleaching and discover if the side effects of increased tooth sensitivity results.

Power bleaching uses light energy to accelerate the process of bleaching in a dental office. The effects of bleaching can last for several months, but may vary depending on the lifestyle of the patient. Factors that decrease any method of whitening include smoking and the ingestion of dark colored liquids like coffee, tea and red wine.