Validation of a fast LC-MS/MS method for the analysis of bisphenol A (BPA) and urethane dimethacrylate (UDMA) in eluates of dental polymer-based materials

Polymer-based materials are widely used in dentistry. However, concerns exist regarding their biocompatibility because monomers such as urethane dimethacrylate (UDMA) and bisphenol A (BPA) may leach from the materials and affect the immune and endocrine systems. Since BPA and UDMA are biologically active even at low concentrations, validated and highly sensitive analytical methods are required. We developed a fast LC-MS/MS method enabling simultaneous detection of BPA and UDMA in artificial saliva using a short column and polarity switching. The method was validated for selectivity, specificity, carry-over, sensitivity, accuracy, precision, recovery, and matrix effects. A water–methanol gradient elution with post-column infusion of 6 mM NH₄F was used to enhance sensitivity. Lower limits of quantification (LLOQ) for UDMA and BPA were of 10pg/ml and 30pg/ml, respectively. The method was used to analyze eluates of thermoformed and 3D-printed polymer-based materials, which released very low amounts of BPA and UDMA. In eluates collected after 1 day, the thermoformed material released more BPA (154.6 ± 128.7 pg/mL) and UDMA (154.8 ± 24.0 pg/mL) than the 3D-printed resin (BPA: 30.7 ± 16.4 pg/mL, UDMA: under LLOQ). Despite the high sensitivity, all values were lower than LLOQ in eluates collected after 1 week. The method provides a fast and reliable tool for the simultaneous quantification of BPA and UDMA in the eluates of dental polymer-based materials, enabling a more accurate assessment of the safety of these materials.