Enough uncertainty surrounds silver-colored metal dental fillings with mercury that U.S. regulators should add more cautions for dentists and patients, a U.S. advisory panel said on Wednesday.

While past data has backed the cavity treatment, the fillings should be accompanied by warnings about unknown risks for vulnerable people such as children and pregnant women, the Food and Drug Administration’s panel of outside advisers said.

“There really is no place for mercury in children,” Suresh Kotagal, a panelist and neurologist at the Mayo Clinic in Rochester, Minnesota, said of the toxic metal.

Metal fillings are used in millions of Americans’ teeth to patch decay, but are increasingly being rejected in favor of bone-colored resin that is more eye-pleasing.

Mercury has been linked to neurological damage at high exposure levels and makes up about half of a metal filling.

While the FDA has said no new specific new evidence has emerged about the fillings’ safety, the agency wants input on how it assessed the data and drew conclusions after receiving four petitions questioning its 2009 ruling. [ID: nN10272453]

While the panel stopped short of urging a ban, it wants the FDA to look at the latest data and reassess its guidance after the agency last year declared the fillings safe.

Their advice follows a divisive two-day public meeting on the FDA’s handling of such fillings, also known as dental amalgam.