Bisphenol A Blood and Saliva Levels Prior To and After Dental Sealent Placement in Adults: An Exploratory Study

Abstract

Placement of dental sealants is an effective therapy for tooth decay prevention and is widely accepted as a standard of care throughout the United States. Sealants are manufactured using the resin component of composite dental materials, formed by reacting glycidyl methacrylate with bisphenol A. Bisphenol A (BPA) is a hormonally active, synthetic chemical that is part of a broad group of chemicals known as endocrine disrupting compounds, xenoestrogens, which mimic bioactivity of estrogen. Laboratory studies using rodents with BPA exposure as low as 2.5 ug/kg body weight/day have revealed increased fertility and mammary and prostate cancer. BPA can leach from a dental sealant if it is not completely polymerized and is released into the oral cavity as a degradation product resulting from enzymatic activity within saliva. This exploratory study examined the presence of BPA systemically in saliva and blood after the placement of pit and fissure sealants in 30 subjects, as measured by the use of a direct-competitive bisphenol A Enzyme Linked ImmunoSorbent Assay (ELISA) and spectrophotometry analysis. Subjects ranged in age from 18-40 years of age and were of mixed gender and ethnicity. Differences in bisphenol A comparing low-dose (1-sealant) and high-dose (4-sealants) groups were examined one hour prior, one hour post, 3 hours post and 24 hours after sealant placement. Data were analyzed using a parametric, 2-way analysis of variance for repeated measures. Results reveal presence of bisphenol A one-hour prior to sealant placement in all saliva samples tested. Salivary BPA concentration levels were highest at the one-hour post time period, remained high at the 3-hour time period and decreased at the 24-hour time period. Bisphenol A was not detected at statistically significant levels in the serum samples after dental sealant placement. Results for salivary BPA revealed statistically significant differences at all post sealant placement time periods for the high dose sealant group. Further research is needed to examine the cumulative estrogenic effects of BPA from dental sealants. Funding for this project through ADHA IOH.