A smile that dazzles, pearly white, should not be bought in a drugstore, says a federal agency, and may even be dangerous. That means the burgeoning market in tooth whiteners, sold over the counter or through the dentist's office, is about to crash at least for a while.
U.S. Food and Drug Administration officials have begun sending letters to the makers of these products informing them that they are selling unapproved drugs and must stop.
Most of the products are bleaching gels made of acidic and/or oxygenating agents such as hydrogen peroxide. In some cases, they are put into a mouthguard and worn overnight or for several hours a day.
"We think these products are drugs, not cosmetics," says Sharon Snider, an FDA spokeswoman. "We have sent letters to about 10 companies so far giving them 15 days to comply."
That means the products must be pulled from store shelves and may not be handed out at the dentist's office, either.
"The companies are going to have to file a new drug application and go through the regular approval process," Snider says. That means providing information and clinical studies that prove the products are safe and effective.
Getting a new drug approved by the FDA can take from five to seven years.
About 20 companies are making the products but the FDA has not yet been able to track all of them down for notification. "We're still looking for some of them," Snider says.
Philip Weintraub, a spokesman for the American Dental Association, cautions consumers who have purchased the products or are considering buying the ones that remain on drugstore shelves to consult their dentists.
"We are concerned because published scientific studies of oxygenating agents show that their regular use may temporarily damage the soft tissues of the mouth the gums, the tongue, the insides of the cheek," he says.
Other studies have shown that whiteners may cause varying degrees of damage to the pulp of the teeth and some may cause irreversible cell changes and enhance the effect of carcinogens, Weintraub says.
Dr. Warren Scherer, an associate professor at the New York University College of Dentistry, has been involved in testing some of the bleaching agents.
The main concern is that people will use too much of the products and cause permanent damage to their teeth, he says.
The FDA action does not ban bleaching by a dentist in the office under controlled conditions.