Determination of bisphenol A and related aromatic compounds released from Bis-GMA-based composites and sealants by high performance liquid chromatography

Most of the composites and sealants used in dentistry are based on bispheno l A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ p olymerization is not complete and that free monomers can be detected by dif ferent analytic methods. Concerns about the estrogenicity of bisphenol A (B PA) and other aromatic components leached from commercial products have bee n expressed. We studied biphenolic components eluted from seven composites and one sealant before and after in vitro polymerization using HPLC and gas chromatography/mass spectrometry and we investigated how pH modifications affect the leaching of these components. We found BPA (maximal amount 1.8 m u g/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 mu g/ mg), bisphenol A diglycidylether (6.1 mu g/mg), Bis-GMA (2.0 mu g/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of diff erent commercial products were maintained under controlled pH and temperatu re conditions. Our results confirm the leaching of estrogenic monomers into the environment by Bis-GMA-based composites and sealants in concentrations at which biologic effects have been demonstrated in in vivo experimental m odels. The main issue with implications for patient care and dentist respon sibility is to further determine the clinical relevance of this estrogenic exposure.