Determination of Bisphenol A and Related Aromatic Compounds Released from Bis-GMA-Based Composites and Sealants by High Performance Liquid Chromatography 

Environmental Health Perspectives v.108, n.1, Jan00

Rosa Pulgar,¹ M. Fatima Olea-Serrano,² Arancha Novillo-Fertrell,² Ana Rivas,³ Patricia Pazos,³ Vicente Pedraza,³ Jose-Manuel Navajas,¹ and Nicolas Olea³

¹Department of Stomatology, School of Odontology; ²Department of Nutrition and Food Sciences, School of Pharmacy; ³Laboratory of Medical Investigations, Department of Radiology, School of Medicine; HUSC-University of Granada, Granada, Spain

Abstract
Most of the composites and sealants used in dentistry are based on bisphenol A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ polymerization is not complete and that free monomers can be detected by different analytic methods. Concerns about the estrogenicity of bisphenol A (BPA) and other aromatic components leached from commercial products have been expressed. We studied biphenolic components eluted from seven composites and one sealant before and after in vitro polymerization using HPLC and gas chromatography/mass spectrometry and we investigated how pH modifications affect the leaching of these components. We found BPA (maximal amount 1.8 µg/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 µg/mg), bisphenol A diglycidylether (6.1 µg/mg), Bis-GMA (2.0 µg/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of different commercial products were maintained under controlled pH and temperature conditions. Our results confirm the leaching of estrogenic monomers into the environment by Bis-GMA-based composites and sealants in concentrations at which biologic effects have been demonstrated in in vivo experimental models. The main issue with implications for patient care and dentist responsibility is to further determine the clinical relevance of this estrogenic exposure. Key words: Bis-GMA, bisphenol A, bisphenol A dimethacrylate, dental composites and sealants. Environ Health Perspect 108:21-27 (2000). [Online 1 December 1999]

http://ehpnet1.niehs.nih.gov/docs/2000/108p21-27pulgar/abstract.html

Address correspondence to N. Olea, Laboratory of Medical Investigations, Department of Radiology, University of Granada, 18071 Granada, Spain. Telephone: 34 58 24 2864. Fax: 34 58 24 9953. E-mail: nolea@goliat.ugr.es

We thank R. Davies for editorial assistance. A. Rivas and P. Pazos are on fellowships from the Spanish Ministry of Education and the Spanish Association Against Cancer, respectively.

This research was supported by grants from the Spanish Ministry of Health (FIS, 95/1959) and Education (CICYT, AMB97-1194-CE) and the Andalusian Regional Government, Department of Health (Consejería de Salud, JA, 231/97).

Received 25 March 1999; accepted 30 July 1999.

Last Updated: December 1, 1999