Novel amino acid-constructed polyalkenoates for dental glass-ionomer restoratives

Several methacrylate or acrylate derivatives of natural amino acids were synthesized and characterized. Based upon these derivatives, novel amino acid-constructed polyalkenoic acids were prepared and used to formulate glass-ionomer cements (GICs) with Fuji II glass filler. The effects of type of derivatives, molar ratio, molecular weight, and powder/liquid ratio were investigated. The results show that amino acid-constructed polyalkenoic acids can be formed only from amino acid methacrylate derivatives or by copolymerization of methacrylate with acrylate derivatives. Strong hydrogen bond interactions failed the polymer formation from acrylate derivatives. The cement composed of poly(methacryloyl glutamic acid-co-acryloyl beta-alanine) with the molar ratio of 8:2 demonstrated the best mechanical strengths along with a workable viscosity. By using the powder/liquid ratio of 3.0/1, the experimental cement exhibited a significantly higher FS (27.7 MPa), and nearly the same CS (198.5 MPa) and DTS (11.8 MPa), as compared to Fuji II (18.9 for FS, 189.1 for CS, and 11.4 MPa for DTS). During aging, the cement showed a significant increase in strength over 24 h, followed by a slow increase over 6 months.