Is Tooth Whitening Harmful?

Health Writer

If you wish your teeth were more pearly white, you’re not alone. Tooth whitening is the most popular cosmetic procedure dentists perform, according to an American Academy of Cosmetic Dentistry survey.

Your teeth naturally darken with age. In part that’s because your tooth enamel slowly absorbs pigments from the foods you eat, says Edmond R. Hewlett, D.D.S., a professor at the UCLA School of Dentistry.

In addition, your tooth enamel becomes more translucent as you get older, so more of the underlying color of the tooth, which typically has an ivory tint, will show through. If you’re unhappy with those changes, whitening agents can help — but will they hurt your teeth?

How the products work

Most tooth whiteners use a bleaching agent like hydrogen peroxide to lighten discolorations. However, restoration work, such as caps, crowns, veneers, or fillings, won’t bleach.

Teeth that have a gray tone or have been darkened by certain drugs, such as antibiotics, antihistamines, or high-blood pressure medications, also won’t lighten up.

To see if you’re a good candidate for tooth whitening, ask your dentist. “He or she can also make sure there aren’t any problems like periodontal disease that could be causing your teeth to discolor,” Hewlett says.

After getting the go-ahead, you can buy do-it-yourself whitening products or have your dentist whiten your teeth.

In-office bleaching

Using a dentist provides quick, noticeable results. He or she will use either a protective gel or a rubber shield to protect your gums, then apply a bleach to your teeth that’s stronger than the products you can purchase yourself.

Your dentist may also send you home with a lower-strength gel to place in trays he makes to fit your teeth. The price for the week of at-home treatment: about $400 to $800, Hewlett says. Some dentists will use a high intensity light to speed up the process, which can bump up the cost to $800 to $1,000 or more.

At-home bleaching

Over-the-counter whiteners take longer but cost much less. They typically also use a gel and trays. You may also try whitening strips. The concentration of the bleaching agent is lower than what your dentist would use in the office, and it usually takes about two to three weeks of treatments before your results plateau. Look for bleaching kits with the American Dental Association Seal of Acceptance. That means it has been tested to be safe and effective for tooth whitening.

Side effects of tooth whiteners

All whiteners can make your teeth more sensitive and painful. “The good news is that these side effects are not permanent,” says Jay Friedman, D.D.S., M.P.H., a consumer health care advocate and a dental adviser to Consumer Reports.

When you stop using the products, the pain should dissipate. To reduce discomfort, you can cut the frequency with which you use the products — say, once a day or every other day instead of twice a day. A toothpaste for sensitive teeth may also help.

If you have sensitive teeth, you may want to skip procedures using a light source. According to a recent report published by the American Association of Cosmetic Dentistry, lasers, lights, or other heating sources speed up the whitening process, but they also heat a tooth internally, which can dehydrate and damage the tooth structure, “increasing the likelihood of sensitivity and pain both during and after the whitening treatment.”

How often should you whiten?

To maintain whiter teeth, most people can use a whitening gel or strips for a couple of days every six months or so, Hewlett says.

Other ways to keep your teeth white

  • Brush your teeth after drinking coffee, tea, or other foods that can stain them, even with just a wet toothbrush, to help prevent stains from settling. Or just rinse your mouth with water.

  • Use a straw to drink cold beverages that can stain teeth. “There is no scientific evidence that it makes a difference, but I would be inclined to think that it does,” Hewlett says.

  • Brush morning and night and floss nightly. Doing that regularly can help your teeth stay white by reducing bacteria in your mouth and preventing plaque build-up.

  • Avoid carbonated beverages and sugary food, which can weaken tooth enamel.

See more helpful articles:

10 Natural Ways to Whiten Your Teeth

Can Toothpaste and Mouthwash Prevent Gum Disease?

Best and Worst Foods for Your Teeth

Could Wine Be Eroding Your Teeth?