Analysis of Bisphenol-A Leaching from Dental Materials by UPLC-MS/MS upon Derivatisation with Pyridine-3-sulfonyl Chloride

Objectives: There is a growing necessity to acquire more profound knowledge on the actual quantity of released eluates from composites, especially with regard to bisphenol-A (BPA) and monomers with a BPA-core. The aim of the present study was to develop a sensitive procedure based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) suitable to characterize the short-term release of BPA in saliva.
Methods: A new UPLC-MS/MS detection method, using a priori extraction step and additional derivatization of BPA with pyridine-3-sulfonyl chloride, was developed and further used to quantify the release of BPA in artificial saliva. Eight different materials were tested:G-aenial anterior and G-aenial posterior (GC Europe); Venus, Venus Pearl and Venus Diamond (Heraeus Kulzer GmbH), Ceram X mono and Dyract (Dentsply DeTrey GmbH) and Filtek Supreme XTE (3M ESPE). Cured specimens (cylindrical disks, 6mm diameter, 2mm thick) were incubated at 37°C in 1mL artificial saliva, which was refreshed daily for one week.
Results: Different experiments were performed to determine the optimal analytical parameters, with a special focus on sample preparation. The final protocol allows to accurately quantify very low levels of BPA in samples of artificial saliva (i.e. 0.5ng BPA/mL). Using the developed method, the daily release over a period of 7 days from different dental composites was characterized and ranged from 1 to 10ng BPA/mL.
Conclusions: The newly developed UPLC-MS/MS method using derivatization allowed the detection of low amounts of BPA, which were released from resin-based composites in artificial saliva. This method can be further used for clinical research focusing on the evaluation of the clinical relevance of BPA release from dental materials.