Silver-colored dental fillings containing mercury may be harmful to pregnant women, children and fetuses, the U.S. Food and Drug Administration said Wednesday after settling a lawsuit filed by several consumer advocates.

The FDA, in its settlement, agreed to alert consumers about the risks on its Web site and to issue a more specific rule for fillings that contain mercury by July 2009, spokeswoman Peper Long told Reuters.

Millions of people in the U.S. are said to have the metal fillings, called amalgams, in their mouths.

"Dental amalgams contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses," the FDA said on its Web site.

"Pregnant women and persons who may have a health condition that makes them more sensitive to mercury exposure, including individuals with existing high levels of mercury bioburden, should not avoid seeking dental care but should discuss options with their health practitioner," the agency said.

The FDA does not recommend the removal of silver fillings.

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