Teeth-whitening products abound. TV bombards us with commercials for whitening toothpastes and mouthwashes. The neighborhood drugstore offers a slew of at-home whitening kits. E-mail inundates us with coupons for professional teeth-whitening services. These products may share the same goal, but their ingredients—and effectiveness—vary.

The American Dental Association (ADA) defines whitening as any process that makes teeth appear whiter. Two main whitening methods exist: those that include bleach and those that don’t. Nonbleach-based whiteners remove extrinsic (i.e., surface) stains, while bleach-containing whiteners use peroxide to remove extrinsic and intrinsic (i.e., deep) stains (ADA 2008).

Nonbleach-Based Whitening

If you want to avoid bleaching your teeth, brighten them at home with a whitening toothpaste. These toothpastes contain abrasives and chemical agents that remove surface stains and can make teeth one shade whiter (WebMD 2010; ADA 2008; Carr 2010).

Whitening toothpastes are generally safe, but excessive use can lead to damaged tooth enamel, so it’s best to use an ADA-approved brand (Carr 2010). A list of ADA-approved whitening toothpastes is available online (see On the Web, page 23).

Bleach-Based Whitening

The ADA recommends you consult your dentist before beginning any bleaching regimen. And not all teeth bleach well: Yellow-colored teeth bleach most successfully, followed by brown-colored teeth. Gray- or purple-hued teeth may not bleach at all (ADA 2008).

Several at-home bleaching options exist. You can purchase an over-the-counter whitening kit at your drugstore, or ask your dentist for an at-home whitening kit. Both contain roughly 10% carbamide peroxide, which breaks down into about 3% hydrogen peroxide to bleach teeth (ADA 2008, 2010; WebMD 2010). Results depend on factors such as type of stain, age, bleach concentration, and treatment time and frequency (ADA 2010).

You can also bleach your teeth at home with a whitening rinse. These act like regular mouthwashes in that they freshen breath and reduce dental plaque, but they also contain hydrogen peroxide. Rinses may not be as effective as other bleaching methods because they only contact teeth during the short period that you gargle each day (WebMD 2010).

Professional teeth whitening provides you with the quickest, most dramatic, but most expensive results. Your dentist applies gum protection, then uses bleach along with a combination of light, heat, or lasers to brighten your smile. Professional bleaching kits contain hydrogen peroxide in concentrations ranging from 15% to 43% (ADA 2010). Light-activated professional whitening can make teeth three to eight shades lighter (ADA 2008; WebMD 2010).

Side Effects

All bleach-containing teeth whiteners can cause tooth sensitivity, soft tissue (e.g., gum) irritation, and—though rare—irreversible tooth damage. Tooth sensitivity often occurs during the early stages of bleaching, and in most cases, tissue irritation results from an improperly fitted tray. Both of these conditions are usually temporary and lessen after your final treatment (ADA 2008).

The long-term side effects of teeth bleaching are unclear, so consult your dentist before using teeth-whitening products. You should also always look for the ADA seal of approval when shopping for any kind of oral hygiene product (ADA 2008).

Conclusion

Teeth whitening isn’t permanent. If you consume foods or drinks that cause staining—such as coffee, red wine, and berries—whitening can start to fade after one month (WebMD 2010; Zamosky 2011).

And remember, consult your dentist before using a bleaching product (ADA 2008), and don’t expect blinding results: Two or three shades lighter than your current color is reasonable (Zamosky 2011).

Do you have a question for the Healthwise column to answer? Send an e-mail to mstreker@nsta.org.

Acknowledgment

Sincere thanks to Lawrence J. Cheskin, associate professor of health, behavior, and society, and director of the Johns Hopkins Weight Management Center at Johns Hopkins University in Baltimore, Maryland, for reviewing this column. l

On the Web

American Dental Association–approved whitening toothpastes

References

American Dental Association (ADA). 2008. Statement on the safety and effectiveness of tooth whitening products.

ADA Council on Scientific Affairs. November 2010. Tooth Whitening/Bleaching: Treatment Considerations for Dentists and Their Patients (PDF)

Carr, A. 2010. Does whitening toothpaste actually whiten teeth? Mayo Clinic.

WebMD. 2010. Teeth whitening.

Zamosky, L. 2011. What you need to know about tooth whiteners. WebMD.