Posted on: Saturday, December 20, 2003

Teeth whitening has some gray areas

By Marilyn Elias
USA Today

The tooth-bleaching business is white-hot.

A growing number of Americans are treating their pearly grays with products touted as effective whiteners. Teeth can be turned snow-white by brief bleaching sessions in a dentist's chair or by inexpensive drugstore products, enthusiasts say.

But skeptics, including some dental researchers, say the benefits are often over-sold, and they worry about long-term safety, especially for whitening junkies who constantly treat their teeth and may buy untested products sold on the Internet.

There's no debate over consumers' passion. Sales have nearly tripled since 2001 for the top 30 over-the-counter products, according to Information Resources Inc., a Chicago market-research firm.

Procter & Gamble started selling bleaching strips to dentists 2› years ago; now more than 40,000 dentists buy them, says spokeswoman Beth Marshall.

Boomers are buying

"Aging baby boomers are more focused than ever on looking and feeling good," says John McIndoe of Information Resources Inc. TV shows such as "Extreme Makeover" and "Ambush Makeover" are fostering more dissatisfaction with flaws and a hunger for perfection, adds Los Angeles psychologist Debbie Then. "All we see is perfect white teeth and bodies made perfect. People think, if you don't have the looks you want, you can go out and buy it all."

To whiten teeth, dentists use hydrogen peroxide, while most over-the-counter products contain carbamide peroxide. Among the options:

• In the dentist's chair: Dentists cover the gums and apply peroxide to the teeth, which are then often are exposed to lights said to enhance bleaching. Many general practice dentists do this. Also, there are tooth-whitening centers, such as the 14 in the BriteSmile Inc., chain. The procedure takes about 90 minutes. Cost: $600 at BriteSmile; $250 to $500 in dental offices.

• Plastic trays: Available over-the-counter, these are flexible, thin plastic molds that fit around the teeth. Gel is squirted into the molds, and they're kept on the teeth for about an hour a day, often in two half-hour sessions. It can take one to three weeks. But some products, such as Rembrandt's 2 Hour White ($20), promise brighter teeth in four 20-minute sessions on a single day. Drugstores sell one-size-fits-all trays. If they're too large, they may be shrunk in hot water, though this can be cumbersome. Dentists often sell made-to-order trays ($200-$350).

• Strips, wands, toothpaste: JUAdhesive strips, such as Crest Whitestrips, fit across the teeth like address labels. These are used twice a day, 30 minutes each time, for one to three weeks. Cost: $25-$35 at stores, $40-$50 from dentists. Makers of wands and toothpastes claim they whiten teeth for a few dollars.

Very little top-quality, financially independent research has been done on tooth whiteners, says David Sarrett, an assistant dean at the dental school of Virginia Commonwealth University in Richmond. The American Dental Association recently asked Sarrett and several other experts to review evidence on safety and effectiveness of tooth whiteners for a consensus paper that will appear in the ADA journal next year.

Effectiveness hinges on how concentrated the peroxide is — dentists typically offer the most concentrated — and how long it's on teeth. Peroxide loses effectiveness if exposed to air, "so poorly fitting trays don't work well,"

Sarrett says. Snug-fitting trays and strips can be effective, but results vary, he adds. And redarkening often starts in a few months.

Studies show a large placebo effect: People given sham bleach say their teeth are much whiter. As for the lights used in dental office procedures, there are contradictory research findings on whether lights intensify the bleaching effect.

Whiteners mask problems

Many who use whiteners feel tooth sensitivity to heat, cold or pressure for a day or two afterward. Also, discolorations can indicate tooth decay or infected root canals, and repeated attempts at do-it-yourself bleaching may delay treatment, Sarrett says. And dental researchers are wary about the surge in whitening products sold on the Web by unknown companies.

Overuse is another concern. "Some people are becoming whitening junkies — they keep doing it over and over and over," says Max Goodson of the Forsyth Institute, a nonprofit group in Boston.

In animal research, large doses of peroxide accelerated the development of cancer when another carcinogen was present, such as exposure to smoke. That doesn't mean typical tooth-whitening regimens will cause cancer in people, Goodson says. But it raises safety questions about constant teeth whitening. "I wouldn't lie there overnight with the trays in my mouth," he says.

When products are used prudently, they are safe, "and most of my patients are thrilled with the results," says John Adomian, a dentist in Santa Monica, Calif. So far, says Sarrett, "there's no evidence tooth whitening is anything but safe."

And many people evidently think it's effective, too: Procter & Gamble expects a billion-dollar U.S. market in a few years, Marshall says.

"We joke about 'that Hollywood smile,' but everyone wants to look like a movie star, including me," she says.