Resin-based dental sealants as a source of human exposure to bisphenol analogues, bisphenol A diglycidyl ether, and its derivatives

Abstract

Although studies have examined leaching of bisphenol A (BPA) from dental sealants into saliva, occurrence of BPA, bisphenol A diglycidyl ether (BADGE), and their derivatives in dental sealants themselves has not been investigated. In this study, concentrations of eight bisphenol analogues (BPs), BADGE and its derivatives (BADGEs), including BADGE‧H2O, BADGE‧HCl, BADGE‧2H2O, BADGE‧2HCl, and BADGE‧H2O‧HCl, were determined in 70 dental sealants collected from the U.S. market. Of the 70 dental sealants analyzed, 65 contained at least one of the target chemicals measured. BADGE‧2H2O was the most abundant compound, found at concentrations of up to 1780 µg/g. The geometric mean (GM) concentration of total BADGEs was 47.8 µg/g, which was two to three orders of magnitude higher than that of total BPs (GM: 539 ng/g). BPA was found in 46% of the sealants and BADGEs was found in 87% of the sealants analyzed. Majority of the dental sealants analyzed in this study were manufactured in the United States and Korea; no significant differences were observed in the concentrations of BPs and BADGEs between the two countries. An exposure assessment was made based on the concentrations of BPs and BADGEs measured in sealants and their application rates in dentistry. The worst-case exposure scenario with the highest measured concentration of total BPs and BADGEs and application on 8 teeth at 8 mg each yielded an estimated daily intake (EDI) of 1670 and 5850 ng/kg·bw/day for adults and children, respectively. Although the EDI is below the specific migration limit set by the European Food Safety Authority, dental sealants are a source of exposure to BPs and BADGEs, especially in children.