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We are daily exposed to a variety of chemicals. One example is the chemical Bisphenol A (BPA). Animal studies indicate that BPA has effects on liver, kidney and breast tissue. Possible endocrine disruption effects contribute to uncertainty around BPA. Some studies have shown that BPA can leak from resin based dental fillings and materials used for orthodontic treatment. Thus, both children and adult patients may be exposed to BPA from dental materials. To confirm and update previous findings, we have investigated the leakage of BPA from some dental materials. Knowledge of products content and properties provides opportunities to choose materials of better quality and less potential adverse health impact. We investigated 4 composite filling materials, 3 sealants and 2 orthodontic bonding materials. The materials were either uncured and solved in methanol or cured. The latter were kept in sterile water for 24 hours or 2 weeks. Samples were then analyzed by UPLC-MS-MS using a C-13 labeled internal standard. Controls had BPA levels between 1.3 and 2.9ng/ml. For all treatment groups, the composite filling material Tetric EvoFlow from Ivoclar-Vivadent and the sealant Delton LC from Dentsply, consistently showed elevated levels of BPA leakage compared to the other materials. The highest BPA content was found in uncured Delton LC (average 87ng/ml). There was little difference in amount of leaked BPA after 24 hours compared to 2 weeks. Our findings substantiate that BPA is still released from some dental materials despite a general focus on potential adverse effects of BPA. BPA is a starting point for synthesis of the monomer Bis-GMA which is commonly used in a variety of dental materials. All products in our study contained Bis-GMA, indicating that the BPA leakage was due to impurities in the materials. The amounts of BPA were relatively low and most likely represent a small contribution to the total BPA exposure. There is currently little reason for concern regarding BPA exposure from dental materials. However, this is based primarily on an assessment of concentrations where toxic effects of BPA have been observed. An impact of low dose exposure and possible estrogenic effects are still unclear. Overall, BPA exposure should be reduced and materials not containing or leaking BPA should be preferred when possible.

 


Reference
The Official Journal of the Society of Toxicology, Volume 156, Issue1, March 2017, Abstract Number 2146, page 271
R. Becher ¹ + ², H. Wellendorf ¹, A. K. Sakhi ², and H. B. Kopperud ¹.

¹ Nordic Institute of Dental Materials, Oslo, Norway; and
² Norwegian Institute of Public Health, Oslo, Norway.
Sponsor: J. Dahl