Bleaching is a cosmetic procedure to whiten the teeth with peroxide. This changes the natural color of the teeth and removes both surface and deep stains. The degree of color change that occurs during bleaching depends on the types of stains present, the peroxide dose, the amount of time on the teeth and how frequently it is performed. Some areas, including artificial crowns, veneers and the roots of the teeth, cannot be whitened by bleaching.

Teeth gradually yellow as they age. Specific types of stains or discolorations also occur and respond differently to bleaching. Extrinsic stains are superficial stains extending no deeper than the enamel of the tooth. Intrinsic stains are deeper stains in the dentin of the tooth. A tooth may also become discolored after a root canal treatment. Age-related and extrinsic stains typically bleach much faster than intrinsic stains.

Several different bleaching options are available. During in-office bleaching, a dentist applies a 15 percent to 35 percent hydrogen peroxide gel or paste to the teeth. During at-home dentist-supervised bleaching, the patient uses a molded mouthpiece to apply the bleaching agent. Many over-the-counter bleaching products are also available. However, the American Dental Association (ADA) recommends that patients consult their dentists before using any bleaching products, including over-the-counter products. Internal bleaching involves chemicals that are placed inside a tooth that has undergone a root canal treatment.

Before bleaching, a dental examination is necessary to help determine if the patient is a good candidate and what treatments are best. Any existing cavities will need to be filled. If the patient will be using an at-home treatment, a mouthpiece will be made. The dentist may request a follow-up after treatment to evaluate the success and to check for gum (gingiva) irritation or tooth sensitivity. Bleaching tends to last for about one to five years, depending on the patient’s personal habits.