It is controversial whether the dental resinous materials containing 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl] propane (BisGMA), which is synthesized from the estrogenic compound bisphenol A (BPA), include unreacted BPA and/or can mimic the effects of natural steroid hormones. In the present study, the estrogenic activities of 3 fissure sealants and 5 adhesive resins, which were all unpolymerized, were determined by means of a reporter gene assay, and the relevance of the components to the estrogenicity was investigated. Two commercially available sealants were confirmed to have estrogenic activity, although none of the tested materials contained BPA. In contrast, hydrophobic monomer bisphenol A dimethacrylate (BPA-DMA), which is also estrogenic, was found to be included in these estrogenic sealants in an amount greater than the minimum concentration to show estrogenicity. This suggests that the estrogenicity of the two proprietary sealants was associated with BPA-DMA rather than with BPA.
Ashby J. (1997). Bisphenol-A dental sealants: the inappropriateness of continued reference to a single female patient (letter). Environ Health Perspect105:362.
2.
Atsuta M., Nakabayashi N., Masuhara E. (1971). Hard methacrylic polymers. II. Copolymers of methyl methacrylate and 2,2-di(4-methacryloxyphenyl)propane. J Biomed Mater Res5:183-195.
3.
Bitman J., Cecil HC (1970). Estrogenic activity of DDT analogs and polychlorinated biphenyls. J Agr Food Chem18:1108-1112.
4.
Bowen RL (1965). Method of preparing a monomer having phenoxy and methacrylate groups linked by hydroxy glyceryl group. US patent3,179,623.
5.
Bulger WH, Muccitelli RM, Kupfer D. (1978). Studies on the in vivo and in vitro estrogenic activities of methoxychlor and its metabolites. Role of hepatic mono-oxygenase in methoxychlor activation. Biochem Pharmacol27:2417-2423.
6.
Cagen SZ, Waechter JM Jr, Dimond SS, Breslin WJ, Butala JH, Jekat FW, et al. (1999). Normal reproductive organ development in CF-1 mice following prenatal exposure to Bisphenol A. Toxicol Sci50:36-44.
7.
Colbom T., vom Saal FS, Soto AM ( 1993). Developmental effects of endocrine-disrupting chemicals in wildlife and humans. Environ Health Perspect101:378-384.
8.
Cooper RL, Kavlock RJ (1997). Endocrine disruptors and reproductive development: a weight-of-evidence overview. J Endocrinol152:159-166.
9.
DeRosa C., Richter P., Pohl H., Jones DE (1998). Environmental exposures that affect the endocrine system: public health implications. J Toxicol Environ Health B Crit Rev1:3-26.
10.
Gaido KW, Leonard LS, Lovell S., Gould JC, Babai D., Portier CJ, et al. (1997). Evaluation of chemicals with endocrine modulating activity in a yeast-based steroid hormone receptor gene transcription assay. Toxicol Appl Pharmacol143:205-212.
11.
Hamid A., Hume WR ( 1997). A study of component release from resin pit and fissure sealants in vitro. Dent Mater13:98-102.
12.
Imai Y. ( 1999). Comments on "estrogenicity of resin-based composites and sealants used in dentistry" (letter). Environ Health Perspect107:A290.
13.
Legler J., van den Brink CE, Brouwer A., Murk AJ, van der Saag PT, Vethaak AD, et al. (1999). Development of a stably transfected estrogen receptor-mediated luciferase reporter gene assay in the human T47D breast cancer cell line. Toxicol Sci48:55-66.
14.
Mariotti A., Soderholm KJ, Johnson S. (1998). The in vivo effects of bisGMA on murine uterine weight, nucleic acids and collagen. Eur J Oral Sci106:1022-1027.
15.
Munksgaard EC, Freund M. (1990). Enzymatic hydrolysis of (di)methacrylates and their polymers. Scand J Dent Res98:261-267.
16.
Nathanson D., Lertpitayakun P., Lamkin MS, Edalatpour M., Chou LL ( 1997). In vitro elution of leachable components from dental sealants. JAm Dent Assoc128:1517-1523.
17.
Olea N., Pulgar R., Perez P., Orea-Serrano F., Rivas A., Novillo-Fertrell A., et al. (1996). Estrogenicity of resin-based composites and sealants used in dentistry. Environ Health Perspect104:298-305.
18.
Peutzfeldt A. (1997). Resin composites in dentistry: the monomer systems . Eur J Oral Sci105:97-116.
19.
Routledge EJ, Sumpter JP (1997). Structural features of alkylphenolic chemicals associated with estrogenic activity. J Biol Chem272:3280-3288.
20.
Ruse ND ( 1997). Xenoestrogenicity and dental materials. J Can Dent Assoc63:833-836.
21.
Ruyter IE, Sjøvik IJ (1981). Composition of dental resin and composite materials . Acta Odontol Scand39:133-146.
22.
Schafer TE, Lapp CA, Hanes CM, Lewis JB, Wataha JC, Schuster GS (1999). Estrogenicity of bisphenol A and bisphenol A dimethacrylate in vitro. J Biomed Mater Res45:192-197.
23.
Sharpe RM, Skakkebaek NE (1993). Are oestrogens involved in falling sperm counts and disorders of the male reproductive tract? Lancet341:1392-1395.
24.
Soderholm KJ, Mariotti A. (1999). Bis-GMA-based resins in dentistry: are they safe ? JAm Dent Assoc130:201-209.
25.
Vankerckhoven H., Lambrechts P., van Beylen M., Vanherle G. (1981). Characterization of composite resins by NMR and TEM. J Dent Res60:1957-1965.
26.
vom Saal FS, Cooke P., Buchanan DL, Palanza P., Thayer KA, Nagel SC, et al. (1998). A physiologically based approach to the study of bisphenol A and other estrogenic chemicals on the size of reproductive organs, daily sperm production, and behavior. Toxicol Ind Health14:239-260.
