Silver dental fillings, formally known as dental amalgams, “contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses,” reads the FDA Web posting.

Pregnant women and people who have health problems that make them more sensitive to mercury’s effects “should not avoid seeking dental care, but should discuss options with their health practitioner.” The FDA said it did not recommend that people who currently have mercury fillings get them removed.

“For 99 percent-plus of people, there probably isn’t harm. But if there is a group of people who might be at risk, they should at least have the knowledge that may be so,” neurologist Karl Kieburtz told the Associated Press.

Mercury fillings may cause danger to a developing human’s brain. The FDA’s decision came as a response to a lawsuit filed on behalf of various consumer advocacy groups.

Silver-colored fillings have been used by dentists for over a hundred years to treat cavities in teeth. Representatives of dental groups say that dental amalgams “remain a safe, affordable and durable cavity-filling choice for dental patients.”

“We don't want these choices taken away based on junk science. We don't want them taken away based on misguided fears,” said Dr. Edmond Hewlett, a dental professor at the University of California, Los Angeles, and an American Dental Association adviser, according to the AP.