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1993.01.21 :  Study -- Mercury-Containing Dental Amalgam

Contact:  Bill Grigg (202) 690-6867
January 21, 1993

       The U.S. Public Health Service today released an
evaluation  of mercury-containing dental amalgam -- silver
fillings -- that says that amalgam has continuing value in
maintaining oral health.  According to the report:
       -- There is no solid evidence of any harm for millions of
Americans who have these fillings, and 
       -- No persuasive reason to believe that avoiding amalgams
or having them removed will have a beneficial effect on health.
       Amalgam has been in use more than 150 years, but the study
was undertaken because of questions raised about the long-term
effects of their mercury content.  Mercury, at high levels, can
produce poisoning symptoms. 
       Amalgam fillings do release small amounts of mercury vapor
which can be absorbed by the body, the report, Dental Amalgam: A
Public Health Service Strategy for Research, Education and
Regulation, said.  It said that mercury could cause allergic
reactions in a few persons* but "there is scant evidence that the
health of the vast majority of people with amalgam is
compromised."
       The report did determine, however, that more extensive
scientific evidence should be gathered to completely rule out any
possibility of long-term health risks from the amalgams -- or
from alternative substances that might be used -- and recommended
a research program to resolve these uncertainties.
       James Mason, M.D., who ordered the study as HHS assistant
secretary for health and head of the Public Health Service, said,
"This report makes clear that, except for a very few people who
may be allergic to substances in the amalgam, there is no
scientific justification for refusing to have amalgam fillings or
for having them removed."
       Produced by representatives of federal health-related
agencies -- the Committee to Coordinate Environmental Health and
Related Programs, or CCEHRP ("See-Surp") -- the report
recommended that the PHS promote the use of fluorides, sealants
and other measures to avoid dental cavities and, thus, the need
for fillings.
       And manufacturers, the report advises, should be required
to disclose to dentists the ingredients in restorative materials
so that dentists can help patients avoid substances that they may
be allergic to.
     Essentially, dental amalgam is a mixture of several metals
including silver, tin, copper and mercury.  The mercury provides
the strength and cohesiveness necessary, and the resulting
amalgam is a popular material for filling cavities because it is
strong, durable and relatively inexpensive.  (Amalgam is used in
about half the 200 million cavity-filling procedures performed
annually.  The other half use such materials as gold, ceramics
and plastics.)
       The study released today is the product of 25 months of
work.  The eight PHS agencies -- including the National
Institutes of Health, the Centers for Disease Control and
Prevention, the Health Resources and Services Administration, the
Indian Health Service and the Food and Drug Administration --
were represented.  The Environmental Protection Agency and
outside experts in toxicology, biomaterials and clinical
dentistry also assisted in the preparation of the report.

                                ###

* A report at a National Institutes of Health biotechnology
conference in 1991 said there were only 50 documented cases of
reactions to amalgam in medical literature since 1906.