Safety of Mercury in Fillings Debated

By ANDREW BRIDGES

WASHINGTON – Federal health officials want to know if a government report reasonably concludes that silver dental fillings aren’t dangerous even though they expose patients to toxic mercury.

The Food and Drug Administration has asked a joint panel of experts to review the study, which looked at 34 recent research studies, and weigh in on whether it reflects current knowledge about the risks associated with the fillings.

The study found "no significant new information" that would change the FDA’s determination that mercury-based fillings don’t harm patients except in rare cases where they have allergic reactions.

Consumer groups opposed to the use of mercury in dentistry dispute that conclusion. The groups petitioned the FDA earlier in the week for an immediate ban on use of the cavity-filler in pregnant women.

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 taper off, though, with many doctors switching to resin composite fillings that blend better with the natural coloring of teeth.

With amalgam fillings, mercury vapor is released when patients chew and brush their teeth. Significant levels of mercury exposure can cause permanent damage to 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 FDA report said.

The two-day, joint meeting of FDA experts on dental products and neurology concludes Thursday.

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On the Net:

Food and Drug Administration: http://www.fda.gov/