HPLC Analysis Of Eluted Monomers From Root Canal Sealer

Objectives: Residual monomer, resulting from incomplete conversion of monomers into polymer, has the potential to cause irritation, inflammation, and an allergic response of the oral mucosa. The aim of this in vitro study was to determine the amount of PEGDMA and Bis EMA eluted from the Epiphany using High Performance Liquid Chromatography (HPLC). Methods: Epiphany (Pentron Clinical Technologies, Wallingford, CT, US) was placed into the plastic molds according to the manufacturer's instructions and polymerized with LED (Elipar Freelight 2, 3M ESPE Dental Products, St. Paul, MN, US) for 20 seconds. Each specimen was immersed in eppendorf tubes containing 200 µl buffered saline solution (PBS) and divided into two groups. In the first group specimens were incubated for 45 minutes (n: 12) and in the second group the specimens were incubated for 24 hour (n: 12) at 37ïC. A stock solution containing 1000 µg/mL PEGDMA and Bis EMA was diluated with methanol and calibration graph for PEGDMA and Bis EMA was obtained. 100µL of the specimen extracts were subjected to HPLC (Agilent Technologies 1200 S, Santa Clara, CA, US). Identification and quantitative analysis of components were performed by comparison of the elution time and the integration of absorption peak area of the eluates with those of the authentic sample. Results: PEGDMA and Bis EMA which was eluted from specimens, was 0,000682 ppm and 4,029812 ppm at 45 minutes, and 0,002469 ppm and 32,61282 ppm at 24 hours, respectively. The amounts of Bis EMA and PEGDMA was significantly different in the extracts that was obtained at 45 minutes and 24 hours (p=0.000). Conclusion: Although the manufacturer informed that Epiphany could be polymerized during 45 minutes, it was found that residual monomer which was eluted from material was kept releasing at 24 hours.