Assessing the estrogenic activity of chemicals present in resin based dental composites and in leachates of commercially available composites using the ERa-CALUX bioassay

Objective. The biocompatibility of resin based dental composites has not yet been fully char-acterized even though certain monomers used in these composites are synthesized from Bisphenol A (BPA), a well-known estrogenic endocrine disruptor. As a result, they show structural relationship to BPA and can contain it as an impurity. Therefore, the estrogenic activity of 9 monomers, 2 photoinitiators, one photostabilizer and leachates of 4 commer-cially available composites was determined. Methods. The ERa-CALUX bioassay was used to determine both agonistic and antagonistic estrogenic activities of the pure compounds (BPA, BisDMA, BisGMA, BisEMA(3), BisEMA(6), BisEMA(10), TEGDMA, TCD-DI-HEA, BADGE, UDMA, HMBP, DMPA, CQ) and the leachates of cured composite disks. The leachates of 4 commercially available composites (Solitaire 2, Ceram.x Spectra ST, G-ae nial Posterior and Filtek Supreme XTE) in water and 0.1 M NaOH (pH = 13, 'worst-case scenario') were tested for estrogenic activity (pooled leachates from 10 cured composite disks). Results. Agonistic estrogenic activity was found for the monomer BisDMA, the photostabi-lizer HMBP and photoinitiator DMPA. All leachates from the 4 tested composites showed significant agonistic estrogenic activity higher than the DMSO control, and the highest activity (potency and efficacy) was found for Solitaire 2, followed by Ceram.x Spectra ST. Furthermore, antagonistic estrogenic activity was found in the leachates from G-ae nial Pos-terior. Significance. These results show that significant estrogenic activity was found in all leachates of the cured composite disks, and that this estrogenicity is most likely due to a mixture effect of multiple estrogenic compounds (including BPA, HMBP and DMPA). This indicates that further research into the endocrine activity of all the compounds that are present these composites (even at low quantities) and their possible mixture effect is warranted guarantee their safe use. (c) 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Automated summary

The biocompatibility of resin-based dental composites, particularly in relation to their estrogenic activity, has not been fully characterized. Research has shown that certain monomers and additives used in these composites, as well as the leachates from commercially available composites, exhibit estrogenic activity. Further investigation is needed to ensure the safe use of these materials.