Dental Sealants Pose No Risk From Leaking Estrogen

Dental Sealants Pose No Risk From Leaking Estrogen
By Suzanne Rostler

NEW YORK, Jan 28 (Reuters Health) -- Dental sealants do not appear to leech
dangerous amounts of an estrogen-like compound, results of a recent study
suggest.

Dental sealants are plastic coatings brushed onto teeth to prevent decay.
Once applied, they harden to form a protective coat. Sealants contain
bisphenol A (BPA) -- a chemical that mimics the effects of estrogen in the
body. BPA may leak into the mouth before the sealants have hardened.

Animal studies showed that pregnant mice who received low doses of BPA were
more likely to give birth to male offspring with larger prostates. However,
the effect of BPA in humans remains unclear.

``Our study showed that the chemical released was not absorbed, so any
possible health effects were not found,'' lead author Dr. Eric Y.K. Fung,
with the University of Nebraska Medical Center College of Dentistry, said in
an interview.

Fung and colleagues collected saliva and blood samples from 40 people, aged
20 to 55 years, who had not previously used dental sealants. Samples were
taken before the sealants (at a concentration of 8 or 32 milligrams) were
applied, and again 1 hour, 3 hours, 1 day, 3 days and 5 days after
application.

Results in the January issue of the Journal of the American Dental
Association show that BPA was detected in some saliva samples 1 and 3 hours
after sealants had been applied. However, saliva samples did not contain BPA
after 3 hours and none of the blood samples contained BPA.

``This finding implies that when BPA is released orally from sealant, it may
not be absorbed systemically, the quantity absorbed is minute and below our
detection limit, or BPA absorbed... is being metabolized,'' the authors
explain.

Further, ``there is no solid evidence that (BPA) is absorbed or causes
adverse health effects.'' And since the chemical is contained in dozens of
commercial products, including the inside of food cans, exposure from other
sources may be greater than from dental sealants, the researchers note.

``Thus, the recent concern regarding the potential estrogenicity of sealants
may be unfounded,'' Fung and colleagues conclude. SOURCE: Journal of the
American Dental Association 2000;131:51-58.