Tooth whitening, also known as bleaching, is a common procedure in general dentistry. As a person ages, the adult teeth often become darker. Teeth can also be internally discolored by antibiotic medications like Tetracycline. Since darkening is commonly associated with aging, having a bright, white smile connotes youth and vigor. That is why tooth whitening is the most common of the cosmetic procedures done by dentists.
There are three common methods to whiten teeth: at home whitening gels, laser enhanced whitening and internal bleaching. Traditionally, at-home whitening is done with bleaching gel which is applied to the teeth using thin soft application trays. Oxidizing agents such as hydrogen peroxide or carbamide peroxide are used to lighten the teeth. The oxidizing agent penetrates the enamel and over a period of time, the dentin layer, lying underneath the enamel, is also bleached, resulting in a whiter appearance.
Laser bleaching uses light energy to accelerate the process of chemical bleaching in a dental office.
The effects of bleaching can last for several months, but may vary depending on the lifestyle of the patient. Research has demonstrated that gradually whitened teeth retain the lighter color longer than do those whitened rapidly.
Internal staining of dentin can discolor the teeth from inside out. Internal bleaching can remedy this. Following root canal treatment, strong oxidizing agents can be applied to the inside of the tooth to further lighten the shade of the tooth prior to restoring it.