Estrogenicity of resin-based composites and sealants used in dentistry.

Abstract

We tested some resin-based composites used in dentistry for their estrogenic activity. A sealant based on bisphenol-A diglycidylether methacrylate (bis-GMA) increased cell yields, progesterone receptor expression, and pS2 secretion in human estrogen-target, serum-sensitive MCF7 breast cancer cells. Estrogenicity was due to bisphenol-A and bisphenol-A dimethacrylate, monomers found in the base paste of the dental sealant and identified by mass spectrometry. Samples of saliva from 18 subjects treated with 50 mg of a bis-GMA-based sealant applied on their molars were collected 1 hr before and after treatment. Bisphenol-A (range 90-931 micrograms) was identified only in saliva collected during a 1-hr period after treatment. The use of bis-GMA-based resins in dentistry, and particularly the use of sealants in children, appears to contribute to human exposure to xenoestrogens.ImagesFigure 1. AFigure 1. BFigure 2.Figure 3. AFigure 3. BFigure 4. AFigure 4. BFigure 5. AFigure 5. BFigure 6. AFigure 6. BFigure 7. AFigure 7. BFigure 8.Figure 9.Figure 10.

Effects of the Environmental Oestrogens Bisphenol A, Tetrachlorobisphenol A, Tetrabromobisphenol A, 4‐Hydroxybiphenyl and 4,4′‐Dihydroxybiphenyl on Oestrogen Receptor Binding, Cell Proliferation and Regulation of Oestrogen Sensitive Proteins in the Human Breast Cancer Cell Line MCF‐7

“…Bisphenol A induced PgR in MCF-7 cells as previously reported (Krishnan et al 1993;Olea et al 1996). It also induced pS2 and reduced the level of cytosolic oestrogen receptors.…”

“…Leakage of bisphenol A has been detected from polycarbonate bottles (Feldman & Krishnan 1995), food cans (Brotons et al 1995), and recycled paper (kitchen roll) (Vinggaard et al 2000). Bisphenol A was also detected in saliva after dental treatment with epoxy resins (Olea et al 1996). Conjugated bisphenol A has been identified in the rainbow trout exposed to sewage plant effluent (Larsson et al 1999;Pedersen & Lindholst 1999).…”

Measurement of bisphenol A levels in human urine

“…The rate of this leaching is under debate ( Brotons et al, 1995;Hoyle and Budway, 1997 ). In addition, the leaching of BPA from dental sealants and fillings has been reported, but these results are also the subject of debate ( Olea et al, 1996;Ashby, 1997;Imai, 1999 ).…”

Chlorination by-products of bisphenol A enhanced retinoid X receptor disrupting effects

“…BPA is widely used to produce polycarbonates and epoxy resins, which are in the raw materials of buckets, feeding bottles, food cans and packaging [7], resulting in various opportunities for human exposure. For instance, human consumption of BPA from epoxy-lined food cans alone was estimated to be about 6.6 g per person per day [8].…”