A Simple Isocratic HPLC Method for the Simultaneous Determination of the Five Most Common Residual Monomers Released from Resin-Based Dental Restorative Materials

Abstract

Resin-based dental restorative materials bonded to tooth structure have become one of the most important groups of dental materials nowadays. The presence of un-reacted monomers, as well as the degradation of resins, caused by hydrolysis and/or enzyme catalysis from saliva and oral environment, can lead to the continuous leaching of monomers with potentially cytotoxic and genotoxic effects for the human organism. A simple and rapid method for the determination of 2-hydroxyethyl methacrylate, bisphenol A, triethylene glycol dimethacrylate, urethane dimethacrylate, and bisphenol A glycerolate dimethacrylate monomers released from dental polymeric materials is described. Chromatographic separation was achieved isocratically, within 11 min, using a Kromasil 100-C₁₈ column (25 cm × 4.6 mm, 5 µM) with CH₃OH:CH₃CN:H₂O, 60:15:25%, v/v, at a flow rate of 1.5 mL/min. The developed method was validated in terms of selectivity, linearity, accuracy, precision, and sensitivity. Within-day repeatability and between-day precision revealed RSD values lower than 11%. The limits of detection ranged from 0.17–0.33 ng/µL. No interference was observed under the described experimental conditions. The method was applied to the study of the monomers released from resin cements through human dentine. All, except for bisphenol A, were found to be released from resin cements through human dentin into the pulp space.

Keywords:

• bisphenol A (BPA)
• bisphenol A glycerolate dimethacrylate (bis-GMA)
• dental composites
• dimethacrylate monomers
• HPLC
• 2-hydroxyethyl methacrylate (HEMA)
• resin cements
• triethylene glycol dimethacrylate (TEGDMA)
• urethane dimethacrylate (UDMA)

Acknowledgments

All authors declare no financial and commercial conflict of interest.