Amalgam aus amerikanischer Sicht
In shift,
FDA says mercury fillings may harm some
By
Marie McCullough
Inquirer
Staff Writer
After years of asserting that mercury in fillings was
safe, the Food and Drug Administration now says it may be harmful to pregnant
women, children, fetuses, and people who are especially sensitive to mercury
exposure.
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"Dental amalgams contain mercury, which may have neurotoxic effects on the
nervous systems of developing children and fetuses," the FDA now says on
its Web site.
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The agency posted the revised assessment online Tuesday as part of a settlement
with consumer advocates. The FDA also committed to issuing special controls on
mercury fillings in July 2009.
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Those controls could range from giving patients information to adding warnings
prohibiting use of the fillings in some people.
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While bans are unlikely, the FDA may conclude that the cavity-repair treatment,
called dental amalgam, should not be used in certain patients such as pregnant
women, FDA spokeswoman Mary Peper Long said.
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The FDA does not recommend removal of old mercury fillings. But it advises
patients who are worried to talk to their doctors.
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"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 . . . , should not avoid seeking dental care," the
FDA Web page says, "but should discuss options with their health
practitioner."
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The American Dental Association said the settlement "in no way changes the
federal agency's approach to or position on dental amalgam."
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Amalgam is "a safe, affordable and durable material that has been used in
the teeth of more than 100 million Americans," the ADA said in a
statement.
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But consumer groups - and some dentists - who fought for the agreement were
exultant.
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"We have won our 10-year battle," declared dentist Stephen Markus of
Haddon Heights.
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Philadelphia Councilwoman Blondell Reynolds Brown, sponsor of a new ordinance
requiring city dentists to give patients a brochure about the potential dangers
of amalgams, said she was "thrilled."
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"The federal government . . . is recognizing . . . that there is value in
giving consumers information," she said.
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Mercury-based metal blends have been used to repair teeth for more than a
century. Resins, porcelain, gold, and other materials used for fillings are
more expensive and not as durable.
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Mercury, which makes up about half the amalgam by weight, chemically bonds to
powdered silver, tin and zinc. While this produces a hard substance, mercury vapor
is released when the filling is placed, removed, and even during chewing.
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shift away from amalgam could affect dental supply firms, health insurers, and
uninsured dental patients.
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The lower cost of amalgam "opens up availability" to patients with
financial constraints, said William Jellison, senior vice president of
Dentsply, a global dental-products firm based in York.
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He said he was not aware of any studies that showed ill effects from mercury
fillings.
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Until Tuesday, the FDA's Web site said federal agencies "have found no
scientific studies that demonstrate dental amalgam harms children or
adults."
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That statement was removed as part of the settlement.
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"Gone, gone, gone are all of FDA's claims that no science exists,"
e-mailed Charles Brown, attorney for the lead group, Consumers for Dental
Choice, in Washington.
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Mercury, which accumulates in the body, is toxic to the brain, the nervous
system, and other organs. There is debate, however, over what level and type of
exposure may be harmful, and whether some people are particularly at risk.
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Epidemiological studies and clinical trials have not connected amalgams to
health problems, but in animal studies, mercury vapors have damaging effects. Numerous
human studies have found that mercury in the blood, brain, and other tissues
increases with the number of amalgam fillings.
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Mercury has been removed from thermometers and vaccines, controls have been
tightened on mercury emissions from coal power plants, and pregnant women have
been warned about consuming fish tainted by mercury.
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In 2006, an FDA advisory committee rejected an FDA report that declared amalgam
fillings safe. Although the panel did not pronounce them unsafe, it said the
FDA's conclusions were not reasonable given the current state of knowledge.
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Whatever controls the FDA imposes, mercury fillings have been landing in fewer
mouths since the 1980s. Surveys estimate that a third to a half of U.S.
dentists have stopped using amalgam, following the lead of many European
countries.
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Markus, the Haddon Heights dentist, made the break 18 years ago. Emerging
research influenced his thinking, but so did his own observations.
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The American Dental Association insisted mercury was "inert" in
fillings, yet it advised special storage precautions – and still the vapors ate
"a hole in the top of the storage jar," he said.
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Now, Markus has a special separator to remove mercury that would otherwise go
into the sewer system. All New Jersey dentists must install separators by late
next year.
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"I saw the future," he said.
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Read the FDA's new thinking on mercury, dental fillings
> via http://go.philly.com/health
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