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

Abstract

Most of the composites and sealants used in dentistry are based on bisphenol A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ polymerization is not complete and that free monomers can be detected by different analytic methods. Concerns about the estrogenicity of bisphenol A (BPA) and other aromatic components leached from commercial products have been 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 microg/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 microg/mg), bisphenol A diglycidylether (6. 1 microg/mg), Bis-GMA (2.0 microg/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of different commercial products were maintained under controlled pH and temperature 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 models. The main issue with implications for patient care and dentist responsibility is to further determine the clinical relevance of this estrogenic exposure.ImagesFigure 1

Oestrogenicity of paper and cardboard extracts used as food containers

“…The presence of BPA in half of the studied samples suggests that this compound is a common contaminant of paper, as reported by other authors (Vinggaard et al 2000). Moreover, the oestrogenic activity of low concentrations of BPA in MCF-7 cells Soto et al 1995;Olea et al 1996;Perez et al 1998;Pulgar et al 2000;Rivas et al 2001) might suggest that this compound is a main cause of the activity observed in the E-Screen assay. However, we found no significant correlation between the presence and concentration of BPA in the samples and their oestrogenicity.…”

N-acetyl cysteine protects human oral keratinocytes from Bis-GMA-induced apoptosis and cell cycle arrest by inhibiting reactive oxygen species-mediated mitochondrial dysfunction and the PI3K/Akt pathway

“…The main matrix component of RBMs is Bisphenol-A-glycidyl methacrylate (Bis-GMA), which is an aromatic monomer with high viscosity and low mobility (Pulgar et al, 2000). The synthesis of Bis-GMA in 1956 initiated the era of RBMs (Lamichhane et al, 2014).…”

Synthesis of fluorinated dimethacrylate monomer and its application in preparing Bis-GMA free dental resin

“…As an endocrine disrupting compound, BPA has already been reported to be responsible for several diseases like male reproductive abnormalities (Li et al, 2011;Meeker et al, 2010) and spermatogenesis impairment (Li et al, 2009;Izumi et al, 2011). Though studies have shown that Bis-GMA cannot hydrolyze into BPA (Schmalz et al, 1999;Atkinson et al, 2002;Kadoma and Tanaka, 2000), BPA has still been detected to be released out of Bis-GMA based dental materials (Soderholm and Mariotti, 1999;Puglar et al, 2000). The effective way to minimize human exposure to BPA as health precaution in dentistry is preparing dental materials with monomers not derived from BPA.…”