Alternative methacrylate-tethering methods for resin-modified glass-ionomer cements

We have explored two novel methacrylatetethering methods for resin-modified glass-ionomer cements using 2-hydroxyethyl methacrylate (HEMA) and glycidyl methacrylate (GM) as a tethering agent. Both were compared with the published method using 2-isocyanatoethyl methacrylate (IEM). The tethering reactions were monitored using FTIR spectroscopy. It was found that IEM and HEMA tethering reactions were relatively fast compared with the GM-tethering, even though all three tethering reactions can be completed within 6 h. The cements composed of the IEM-tethered polymer showed the highest CS, DTS, and modulus, followed by the cements composed of the HEMA- and GM-tethered polymers, which was attributed to different chemical bonds introduced. It appears that both alternative tethering methods are quite equivalent to IEM-tethering based on the strength and reaction efficiency. The results suggest that HEMA and GM can be used as promising methacrylatetethering alternatives for resin-modified glass-ionomer applications.