American Dental Association Statement on Bisphenol A Leaching From Dental Sealants
of Bisphenol A Lacking in Dental Sealants
American Dental Association Statement Document 4aug98 rev.30may01
ADA test a failure by design
The testing paid for by the ADA only detected levels as low as 5ppb (parts per billion). Concentrations in the ppt (part per trillion) range went undetected). Since BPA mimics the hormone estrogen, which is active in the ppt range, this test was doomed to failure by its design.
A 1996 study conducted by researchers in Spain and published in Environmental Health Perspectives found that a chemical, bisphenol A (BPA), which can potentially mimic human estrogen, leached out of dental sealants.1 Although the study did not show any causal effect between the presence of BPA and any health condition, the ADA was sufficiently concerned about this research to conduct its own evaluation.
Of the 12 brands of dental sealants that currently carry the ADA Seal of Acceptance, 11 of the 12 materials leached no detectable BPA on first analysis; on second analysis, one sealant leached a trace amount of BPA within the test sensitivity (5 parts per billion). The manufacturer of this sealant was contacted. After additional quality control procedures were implemented in the manufacturing process, detectable BPA was successfully eliminated in the final product. (BPA is not a direct ingredient of dental sealants; it is a starting raw chemical that appears in the final product only when the raw materials fail to fully react.2)
Hence, none of the dental sealants that carry the ADA Seal release detectable BPA, although it must be emphasized that there is no evidence to suggest a link between any adverse health condition and BPA leached out of dental sealants.
The ADA also looked beyond product chemistry for the presence of BPA in dental sealants. The Association tested the blood of dentists who had dental sealants on their teeth and those who did not. The ADA examined 40 blood samples: 30 were from dentists with one to 16 sealed surfaces, and ten samples were from dentists who had no sealants. BPA was not found in any of the blood samples from either group, suggesting that if BPA is leached from dental sealants it is not detectable in blood tests; thus, it does not present an estrogenic hazard.3
In addition to its laboratory studies, the ADA worked with researchers at University of Nebraska Dental School on a clinical project to measure BPA exposure during and after sealant application. Dental sealants were applied to test subjects, then saliva and blood samples were collected at various time intervals after sealant application. This study showed that BPA released orally from a dental sealant may either not be absorbed or is not detectable at or above 5ppb when measured in systemic circulation.4
An article in the Journal of American Dental Association corroborates ADA findings regarding BPA and dental sealants. Researchers at Boston University School of Dental Medicine who tested seven brands of sealants confirmed that none released any BPA.4-5
- Olea N, Pulgar R, Perez P, Olea-Serrano, Rivas A, Novillo-Fertrell, Pedraza V, Soto A, Sonnenschein C. Estrogenicity of resin-based composites and sealants used in dentistry. Environ Health Perspect, 1996;104:298-305.
- Bowen RL. Use of epoxy resins in restoratove materials. J Dent Res, 1956;35:360-369.
- Siew C, Miaw CL, Chou HN, Gruninger SE, Geary R, Fan PL, Meyer DM. Determination of bisphenol A in dentist serum samples (Abstract 1070). J Dent Res, 1998;77(Special Issue A).
- Fung EYK, Ewoldsen NO, St.Germain HA, Marx DB, Miaw C-L, Siew C, Chou H-N, Gruninger SE, Meyer DM. Pharmacokinetics of bisphenol A released from a dental sealant. J Amer Dent Assoc, 2000; 131:51-58.
- Nathanson D, Lertpitayakun P, Lamkin M, Edalatpour M, Chou LL. In vitro elution of leachable components from dental sealants. J Amer Dent Assoc, 1997;128(11):1517-1523.
Document Posted: August 04, 1998
Page Updated: May 30, 2001
Document address: http://www.ada.org/prof/prac/issues/statements/seal-est.html
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