Silver filling report a reason to smile

WASHINGTON – Silver fillings used to patch cavities aren’t dangerous even though they expose dental patients to the toxic metal mercury, federal health researchers said Friday.

The Food and Drug Administration reviewed 34 recent research studies and found “no significant new information” that would change its determination that mercury-based fillings don’t harm patients, except in rare cases where they have allergic reactions.

The FDA released a draft of its review ahead of a two-day meeting next week to discuss the safety of mercury used in dentistry.

Consumer groups opposed to its use disputed the FDA’s conclusions. The groups plan to petition the agency for an immediate ban on use of the cavity-filler in pregnant women.

“The science is over. There is no safe level of exposure,” said Charles Brown, a lawyer for one of the groups, Consumers for Dental Choice. “The only thing standing between this and a ban is politics. They are still pretending it is a scientific question, but it isn’t.”

Amalgam fillings, also called silver fillings, by weight are about 50 percent mercury, joined with silver, copper and tin. Dentists have used amalgam to fill cavities since the 1800s. Today, tens of millions of Americans receive mercury fillings each year. Amalgam use has begun to decline, however, with many doctors switching to resin composite fillings, considered more appealing since they blend better with the natural coloring of teeth.

With amalgam fillings, mercury vapor is released through tooth-brushing and chewing. In general, significant levels of mercury exposure can permanently damage the brain and kidneys. Fetuses and children are especially sensitive to its harmful effects.

Scientists have found that mercury levels in the blood, urine and body tissues rise the more mercury fillings a person has. However, even among people with numerous fillings, exposure levels are well below those known to be harmful, the report said.