Also known as bleaching, this treatment will lighten teeth that are stained or discolored from such things as:

Whitening creates a brighter, more esthetic appearance by reversing the discoloration of tooth enamel with an oxygenation process provided by a safe peroxide gel. For at-home whitening, patients have an initial appointment at the dental office to take impressions so that custom trays may be made that fit snugly around their teeth. On a second visit, the trays are checked to ensure comfortable fit, to review instructions on usage, and to take photographs that document the starting color of teeth.
Each day (after thorough brushing and flossing) a small quantity of a whitening gel is placed into the custom trays which are then placed over the teeth. Most commonly, the trays are worn for an hour or two. This is done over a period of two to four weeks or until the desired result is achieved.

The in-office procedure uses stronger concentrations that are applied to the teeth for a short time and strictly controlled by the Dentist. This may be done alone or in combination with the at-home process.
Although tooth whitening is not permanent, annual touchups of only a few days at a time can maintain the original whitened result.

Additional notes:
1. All professional and commercial products share a common peroxide chemistry that may vary to small degrees based on concentration, chemical stabilizers, flavors
2. The in-office treatments have become more and more popular, but are actually less effective for the patient because the results are not as stable as those done at home, and costs much more because they are done in the dentist office where chair time is most costly