FDA: Possible Risk From Dental Fillings
To Settle Lawsuit, FDA Now Says Mercury From Fillings Might Pose Risk to Some
But the FDA never issued a final ruling. It's proposed "white paper" on the topic was voted down in a 13-7 vote by a 2006 advisory panel made up of experts in dentistry and in neurology.
Neurologist Karl Kieburtz, MD, of the University of Rochester, co-chaired the panel.
"The panel's concern was there are populations that are particularly susceptible to the neurological effects of mercury and might experience these effects at the very low levels of exposure seen with dental amalgam," Kieburtz tells WebMD. "That was the tenor of the committee -- 'Let's consider vulnerable populations' -- so we said fair enough, these vulnerable populations should at least get a warning."
Kieburtz notes that panel members also agreed that there was no cause for alarm and said there was no reason for pregnant women or others to have their dental fillings removed.
"To the best of my knowledge, there is no clinical evidence in humans that dental amalgams have led to harm," Kieburtz says. "Is there a theoretical reason to suspect harm? Yes. There is a rationale for concern, but no evidence there is harm. So there is a theoretical concern and a lack of evidence and that has led to a precautionary rule."
Indeed, clinical studies suggest that dental fillings cause no harm. But because millions and millions of children and pregnant women receive the fillings, even rare events would affect thousands of people.
Amalgam fillings are made from liquid mercury mixed with a powder containing silver, tin, copper, zinc, and other metals. It was once thought that the mercury in fillings was permanently trapped in the amalgam. Not any more.
When people chew, the fillings emit mercury vapor that is absorbed by the body. Even for people with lots of fillings, it's a small amount of mercury.
But since mercury is toxic even at very low levels, there's growing concern that the mercury in fillings could be the straw that breaks the camel's back for people with other mercury exposures. And dental professionals are routinely exposed to the vapors.
Even now, the FDA does not recommend that people have their fillings removed. But the agency does say that people concerned about the possible health effects of dental fillings should talk with their "qualified health care practitioner."