Synthesis And Polymerization Of BisS-GMA Resin Monomer

Composite resin is a common dental material for dental defection restoration. However, it have some defaults,such as volume shrinkage, lower adhesive strength and discoloration after long use.To improve the qualitity of composite resins, many researchers focuse on the improvment of resin monomer or developing new dental resin monomer.Objective: To synthesize a new dental resin monomer bisphenol-S-bis(3-methacrylato-2-hydroxy propyl) ether (BisS-GMA) by a new method, and evaluate it's polymerization with TEGDMA on the degree of conversion, curing time, volume shrinkage and adhensive strength.Methods: GMA is pured before synthesization, and BisS-GMA is synthesized by pured GMA and Bisphenol-S in the presence of a catalyst DMT in 55-60℃for 21 h, or another catalyst Et₃N in 70℃for 20h.BisS-GMA and TEGDMA(7:3) was polymerized in both chemical cure(BPO/DHPT/TSS)and light cure (CQ/DMAEMA) , and the degree of conversion of each composite was measured by fourier transformation infrared spectroscopy after being cured. Moreover, the curing time, polymeration shrinkage and tensile bonding strength are also evaluated in both the mass ratio of 70/30 or 60/40.The polymerization of Bis-GMA and TEGDMA is also tested as control.Results: BisS-GMA can be synthesized with a proper proportion of GMA and Bisphenol-S with the catalyst DMT or Et₃N, which can be proved by FTIR and ¹HNMR. It is better to use DMT as it is also a accelerator in the polymerization of BisS-GMA.BisS-GMA can polymerized well with TEGDMA, with the conversion 60.7% and 54.1% in light cure and chemical cure. The curing time is shorter and polymerazation shrinkage is lower than the Bis-GMA control group. This Bis-S type monomer BisS-GMA is more reactive toward cross-linking polymerization than the corresponding Bis-GMA type monomer, and BisS-GMA shows greater adhesive strength than Bis-GMA. Conclusion: BisS-GMA can be synthesised by the catalyst DMT, which is better for detal matreial as DMT is a accelerator. BisS-GMA is a new high reactive monomer because of the sulfuryl, and can polymerized well with TEGDMA.And it is a promising dental resin monomer,with short curing time, lower volume shrinkage and higher adhensive strength.