Release Of Monomers From Dental Composite Materials - An Invitro Study

Resin composites have been used as an alternative to amalgam, ceramic and gold restorations. According to various studies the amount of monomer conversion to polymer is between 43-73%.These monomers have shown wide variety of adverse biological reactions.In this study release of BisGMA and TEGDMA monomers from two flowable dental composite materials, Tetric N-flow and Esthet X-flow were assessed. Three groups (n=10) of each material were fabricated, one for each polymerization time of: 20s, 30s, and 40s. The samples were stored immediately in the storage medium of 2ml of absolute alcohol at room temperature which was renewed after 24 hours and was stored for 7 more days. Ethanol samples were measured using HPLC Unit to know the amount of monomers released. Regardless of polymerization time, the material or storage time, a higher amount of BisGMA was released compared to TEGDMA. The release of monomers did not reduced after 24 hours and 7 days after polymerization. The 40s that are usually used for the polymerization of resin composites seems insufficient in order to prevent higher release of monomers.