TUESDAY, July 28, 2009 (HealthDay News) -- U.S. health authorities on Tuesday placed tighter safety controls on the use of mercury dental fillings.
The U.S. Food and Drug Administration will now categorize the fillings as Class II devices, which puts them into the middle range of risk. Class II devices usually carry some kind of precautions regarding their use.
But U.S. health officials noted that the fillings pose no real harm to most people.
"Patients are not at risk for long-term, mercury-related adverse health events," Dr. Susan Runner, acting director of the Division of Anesthesiology, General Hospital, Infection Control and Dental Devices, part of the U.S. Food and Drug Administration's Center for Devices and Radiological Health, said during a news conference Tuesday afternoon. "There have only been 141 adverse event reports over 20 years. None resulted in death."
The agency did recommend the following labeling changes: a warning against the use of these fillings in patients with mercury allergy; a warning that dental professionals use adequate ventilation when handling the material for the fillings; and a statement discussing the scientific evidence on the benefits and risks of dental amalgam.
"We're not contraindicating dental amalgam in any patient group [other than those who have allergies]," Runner noted during the news conference.
The new ruling brought an angry reaction from the consumer organization Consumers for Dental Choice.
"I'm outraged. FDA broke its word," said Charles Brown, the group's national counsel. "They put a warning a year ago on the web site and promised to keep those warnings on the web site that warned of neurological damage to children and unborn children. Bowing to the dental products industry, FDA has, for the first time in memory, withdrawn a warning about neurological harm to children and the unborn. It's a contemptuous attitude toward lower income and minority children because they're the ones that get amalgam. The rich get resin."
The agency's latest move follows a lengthy debate on the supposed dangers of these fillings, which was capped by a lawsuit filed in 2006 against the FDA by several consumer groups, including Moms Against Mercury and Consumers for Dental Choice.
As part of that settlement, the FDA agreed to classify mercury fillings, also known as dental amalgam, by July 28, 2009, and posted a notice on its Web site that said: "Dental amalgams contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses."
The American Dental Association (ADA), one of the organizations that had expected a Class II classification, supported the FDA action.
"The FDA has left the decision about dental treatment right where it needs to be -- between the dentist and the patient," the ADA's president, Dr. John Findley, said in a prepared statement. "This decision underscores what the ADA has long supported -- a discussion between dentists and patients about the full range of treatment options to help patients make educated decisions regarding their dental care."
"Right now, it's confusing because [amalgam] is classified according to its different components. The encapsulated amalgam functions as a unit, so it just makes sense," Dr. Edmond Hewlett, an ADA consumer advisor and an associate professor at the UCLA School of Dentistry, said before the ruling. "And it's reasonable to expect special controls such as precautions for people who are hypersensitive or are allergic to amalgam as well as proper handling guidelines for dental personnel."
Encapsulated amalgam contains two parts, a metal alloy as well as mercury, which are delivered in separate sections that are mixed after they have been delivered to the dentist's office, said Dr. Michael Fleming, a member of the FDA Dental Products Panel.
Fleming emphasized that he was not speaking on behalf of the FDA.
The panel, which met in 2006 to review the issue, did not find that amalgam was unsafe. "We said you can't make a determination of safety based on the documents the FDA produced," Fleming said.
"The ADA has not come out and said it is unsafe in pregnant women and children, but that we need more information," Hewlett added.
Fleming said before the ruling that he expected the FDA to incorporate the committee's recommendations, which included making sure that patients be informed of the mercury content of the product and beefing up precautions for pregnant women and women of child-bearing age.
But Runner said the FDA found that "...concentrations of mercury in breast milk is an order of magnitude lower than EPA protective dose. FDA does not believe that maternal dental amalgam fillings put infants at risk."
Dental amalgam contains elemental mercury combined with other metals such as silver, copper, tin and zinc. The fillings, about 50 percent mercury, have been used for generations to stabilize decaying teeth. Dental experts contend that when mercury is bound to the other metals it's encapsulated and doesn't pose a health risk. Consumer groups, however, contend that mercury, a known neurotoxin, does leak out in the form of mercury vapor and then gets into the bloodstream.
However, Runner said Tuesday that "exposure to mercury vapor from dental amalgam do not put individuals age 6 and older at risk."
According to the ADA, the use of amalgam is declining. In 1990, dental amalgams made up 67.6 percent of all dental restorations, but by 1999 it was 45.3 percent and, in 2003, an estimated 30 percent. Cavities that previously would have been treated with dental amalgam are now mostly filled with a resin composite.
Several countries have already either banned or advised against the use of mercury fillings.
More information
The U.S. Centers for Disease Control and Prevention has more on amalgam fillings.
