Measurement of estrogenic activity of chemicals for the development of new dental polymers.

The estrogenic activities of 13 Bisphenol-A (BPA)-related chemicals for development of new polymers by three in vitro bioassay have been examined in the presence and absence of a post-mitochondrial metabolizing system (S9 mix). BPA, Bisphenol-B (BPB), Bisphenol-F (BPF), Bisphenol-S (BPS), 4,4-ethylidenebisphenol (BP1), 4,4-dihydroxybenzophenone (BP2), 2,2-bis (4-hydroxyphenyl)-hexafluoropropane (BP3), 4,4-(1,4-phenylenediisopropylidene) bisphenol (BP4), 4,4-cyclohexylidenebisphenol (BP5), 4,4-dihydroxydiphenyl ether (BP6), 4-hydroxydiphenylmethane (BP7), 4-cumylphenol (BP8) and 4,4-dihydroxydiphenyl sulfide (BP9) were each diluted with dimethyl sulfoxide to final concentrations ranging from 10(-7) to 10(-3) M in both the yeast two-hybrid system and in a fluorescence polarization system. Dilutions of 10(-9) to 10(-4) M were assayed in the E-screen, respectively. Except for BPS and BP4, the chemicals tested showed estrogenic activity in the absence of cut S9 mix preparation and the activity was enhanced with S9 mix. BPS, which was initially negative, was active with S9 mix in the yeast two-hybrid system. BP2 was weakly estrogenic with or without S9 mix. Chemicals other than BP2 were positive in the competition binding assay. All chemicals tested showed estrogenic activity in the E-screen, the concentration level of which was 10(4) times lower than those of the other two assays.