Visible light-curable N-methacryloyl-glutamic acid modified polyelectrolytes for use in dental applications

The visible light-curable N-methacryloylglutamic acid (MGA) modified polyme rs (VLC MGA MPs), with the optimal molar ratio of 8:1:1 (acrylic acid: itac onic acid: MGA) in the copolymer backbone, were synthesized by a one pot re action. The compressive strength (CS) was used as the initial basic screeni ng property to determine the best graft ratio. A statistical design of expe riment (DOE) technique was utilized to predict the optimal formulation for the VLC MGA MP with the best graft ratio based on the CS. The VLC MGA MPs w ere synthesized under the same reaction conditions, using a free-radical po lymerization process to produce the copolymers, followed by grafting 2-isoc yanatoethyl methacrylate (IEM) onto the copolymer backbone to form the VLC materials. Specimens were prepared by mixing the polymer solutions with the basic glass powders and their strength values were measured after the test specimens were conditioned in distilled water at 37 degrees C for 7 days. In this study, polymer solutions containing VLC MGA MPs were formulated wit h the glass powder used in the commercial Fuji II LC (GC America) material to determine the CS. Diametral tensile strengths (DTS) of the produced mate rials were also determined. Based only on the CS value, the VLC MGA MP with 15 molar % of IEM grafting was the best material. The optimal formulation for this copolymer, i. e., the system having the highest CS value, was foun d to be at the weight ratio of 52.5:18:29.5 (VLC MGA MP:HEMA:water), provid ing an improvement in CS of 30% compared to the commercial Fuji II LC syste m. This formulation was also mixed with the glass powder used in the Vitrem er(TM) (3M Dental Products) material to determine its mechanical properties . The MGA monomer was also further evaluated as a reactive diluent/modifier for commercial VLC formulations, such as the Fuji II LC and Vitremer(TM), as well as the optimal experimental VLC formulation. In the latter effort, the MGA monomer was used to partly replace HEMA in the optimal experimental VLC formulation, providing additional evidence that MGA was useful to form ulate improved VLC glass-ionomers.