Tooth-bleaching

With the advent of new treatments, a better smile is now within reach of more people. One of the most popular cosmetic procedures is bleaching. The natural light ivory color of enamel can turn to yellow, orange, brown, gray—even blue or green. Causes of discoloration include staining from coffee or tobacco, injury that has damaged the pulp, ingestion of the antibiotic tetracycline or high levels of fluoride while the teeth are developing, corrosion from silver fillings, and the natural wearing away of the enamel with age.

Although many stains can be successfully removed with a bleaching technique, bleaching may be uncomfortable for people with sensitive teeth or an exposed root. Several different bleaching techniques are available.

Chair-side bleaching

Your dentist etches your teeth with an acid solution and then applies an oxidizing agent to the enamel. Your teeth are exposed to a bright light or a laser to hasten the lightening. It usually takes three to four sessions, each lasting about 30–60 minutes, to achieve the color you want. A newer technique, called power bleaching, uses a highly concentrated form of hydrogen peroxide as the lightening agent. It can deliver results in just one session. Bleaching is temporary, however. Your teeth will darken again within one to three years, and you may need to repeat the procedure. Costs vary, with some dentists charging a fee $75 and $225 a session, and others charging a single fee of $300 or more.

Home bleaching (dentist prescribed)

Your dentist will make a custom-fitted mouthpiece to hold the bleaching chemicals (carbamide peroxide or hydrogen peroxide). You then perform the bleaching at home by spreading the chemicals into the mouthpiece and putting it on for the recommended period (between 30 minutes and several hours) each day for a week or two. This procedure generally costs between $200 and $600.

Bleaching pulp-damaged teeth

When the pulp is dead or injured, the tooth will darken. To correct this problem, your dentist can rinse the pulp chamber with a bleaching agent while performing root canal therapy. If the stain persists or the tooth darkens after the root canal is completed, your dentist can reopen the pulp chamber and fill it with bleach for several minutes under a heat light. This process may have to be repeated several times. Alternately, the dentist can fill the pulp chamber with bleaching solution and cover it with a temporary filling. In this case, you'll need to return after a few days to have the bleach removed and the tooth permanently sealed. Costs vary; some practices charge between $300 and $400 per tooth.

Over-the-counter bleaching kits

These kits operate on the same principles as the professional products. You start with an acid rinse, then apply a hydrogen peroxide gel, and finally coat the tooth with a whitening pigment. Many over-the-counter tooth whitening strips or kits cost as little as $15 to $40.

Many consumers opt for this bleaching method because it is less expensive than other techniques, But good results cannot be ensured. Without professional diagnosis, it's hard to determine the source of discoloration and the effectiveness of the bleaching agent,