Many options exist for whitening teeth

Q. Should I whiten my teeth at home or have my dentist do it?

A. If discolored teeth are making you self-conscious, you've got a lot to smile about. The interest in whitening teeth has grown greatly in the past decade, and these days there are many teeth-whitening options — both at the drugstore and at the dentist's office.

The first permanent teeth we have as kids tend to be very white. Then, over the years, the teeth get exposed to substances in food or drink (or cigarette smoke) that stain the enamel.

Teeth-whitening products bleach, or whiten, your teeth using peroxides. Your dentist can perform a bleaching process in the office or prescribe a procedure for you to do at home:

• Dental office bleaching: Your dentist etches your teeth with an acid solution, then applies an oxidizing agent. A bright light or laser hastens the lightening. It usually takes three to four sessions of 30 to 60 minutes each to achieve the color you want. The results may be more uniform than home-bleaching methods.

• Home bleaching (dentist-prescribed): Your dentist makes a custom-fitted mouthpiece to hold the bleaching chemical. You spread the chemical into the mouthpiece and put it on for 30 minutes to several hours each day for a week or two.

You can buy the following products on your own and bypass the dentist's office:

• Over-the-counter bleaching kits: These products also contain peroxide. They aren't usually as strong as those at your dentist's office, but they're substantially cheaper.

• Whitening strips: Thin, flexible pieces of plastic you apply directly onto your teeth for about 30 minutes, once or twice a day. You repeat the process for five to 14 days.

• Gels: You apply the gel before you go to bed and leave it on every night for about two weeks.

• Combination gel and light: You apply a whitening gel to the teeth you want to whiten, then hold a special light up to your teeth for two minutes to boost its whitening effects.

• Whitening rinses: You rinse for 60 seconds twice a day before brushing, for at least 12 weeks.

No whitening method is clearly better than another. The determining factor is usually cost. Teeth whitening is expensive, and it's not usually covered by dental insurance.

I can see why a movie star whose teeth were going to be seen in close-up by millions of people might want to spend a few bucks whitening them. But there are many other parts of my body besides my teeth that I would rather restore to the state they were in when I was a kid. In any event, if you want to do it, you've got plenty of safe options.

• Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: AskDoctorK.com.