The U.S. Food and Drug Administration last week recognized mercury's possible harmful effects on pregnant women, nursing women, young children, people with compromised immune systems, people sensitive to mercury exposure, and unborn children.

The FDA had so far maintained that amalgam fillings were safe, but it recognized the harmful effects of mercury under the pressure from the consumer advocacy groups such as Moms Against Mercury. The agency, however, stated that more researches are needed on the issue.

The new information posted on FDA Web site, about mercury amalgam's possible risks stated, "Dental amalgams contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses.” – "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."

According to FDA spokeswoman Mary Peper Long, more than likely the FDA will not ban amalgam fillings. Instead, its new guidelines as of July 2009 may restrict the use of amalgam in some patients.

Consumer advocacy groups such as Moms Against Mercury and Consumers for Dental Choice have been advocating that mercury fillings may trigger health problems, such as Alzheimer's disease, brain damage, irritability (erethism), kidney damage, migraines, and multiple sclerosis.

Mercury has been listed as a neurotoxin by the Environmental Protection Agency; it (mercury) can interfere with brain development and cognitive and motor skills. However, the American Dental Association (ADA) considers amalgam safe, as does the National Institutes of Health

According to the American Dental Association (ADA), more than 100 million Americans have mercury dental amalgams. The use, however, declined as consumer concern over mercury rose.