FDA: Possible Risk From Dental Fillings
To Settle Lawsuit, FDA Now Says Mercury From Fillings Might Pose Risk to Some
By
Daniel J. DeNoon
WebMD Health News
Reviewed By
Louise Chang, MD
June 5, 2008 — Mercury from amalgam dental fillings may be toxic to
children and developing fetuses, the FDA now admits.
Experts say there's no proof that dental fillings cause harm to consumers.
But they also say there's no proof that the fillings — which are half mercury
by weight — are entirely safe.
On its web site, the FDA has dropped much of its reassuring language about
dental amalgam. And it's added what amounts to a warning: "Dental amalgams
contain mercury, which may have neurotoxic effects on the nervous systems of
developing children and fetuses."
And there's more. "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 FDA web site now says.
The changes come in response to a lawsuit filed by consumer groups and
individuals concerned about mercury exposure. To settle the suit, the FDA
agreed to update its web site.
And the federal agency also agreed to rule — within one year — on exactly
how dental amalgam products should be regulated, and exactly what warnings
consumers should receive from their dentists and doctors.
"It's been a long time coming," Nick Brooks, a staffer for Consumers
for Dental Choice, one of the groups that brought the lawsuit, tells WebMD.
"This is a good thing. It will be good to have a rule finalized in a
year," FDA spokeswoman Peper Long tells WebMD. "In some cases, we know
mercury can have effects on the nervous system. It is something we need
information on so we can give the public the best information on the risk from
a product like this."
The FDA in 2002 proposed to classify the mercury-containing fillings as a
Class II device — meaning a device that isn't absolutely safe and should carry
some kind of special controls (a Class I device, like a Band-Aid, needs no
warning; a Class III device, like a cardiac defibrillator, requires specific
FDA approval).
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."
SOURCES: FDA web site: "Questions and Answers on Dental Amalgam." FDA web site (cached Oct. 31, 2006): "Questions and Answers on Dental
Amalgam." Complaint and Settlement Agreement, "Moms Against Mercury et al. v.
Andrew von Eschenbach et al." Civ. No. 07-2332-ESH FDA web site: Transcript, "Joint Meeting of the Dental Products Panel of
the Medical Devices Advisory Committee of the Center for Devices and
Radiological Health and the Peripheral and Central Nervous System Drugs
Advisory Committee of the Center for Drug Evaluation and Research," Sept.
6-7, 2006. Consumers for Dental Choice web site. Moms Against Mercury web site. Peper Long, spokesperson, FDA. Karl Kieburtz, MD, professor of neurology and community and preventive medicine, University of Rochester, N.Y. WebMD Health News: "No Harm Found in Amalgam Fillings." WebMD Health News: "Safety of Dental Fillings Questioned."
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