Novel amino acid modified zinc polycarboxylates for improved dental cements

Objective The objective of this study was to develop a novel amino acid modified zinc/calcium polycarboxylate cement system, formulate the cements, and evaluate their mechanical strengths. Materials and methods Acrylate and methacrylate derivatives of four amino acids were synthesized and characterized using FT-IR and 1HNMR spectroscopy. The derivatives were formulated with polymer having pendent methacrylate group, water, and synthesized novel filler. Compressive (CS) as well as flexural strengths (FS) and viscosities of the resin liquids were used as tools to evaluate the formulations and formed cements. The specimens for CS and FS tests were conditioned in distilled water at 37 °C for 24 h and 7 d, respectively, prior to testing. Results The measured CS and FS of the cements was in the decreasing order of methacryloyl beta-alanine>acryloyl glutamic acid=acryloyl beta-alanine>methacryloyl glutamic acid>2-hydroxyethyl methacrylate. Methacryloyl beta-alanine was selected for further formulations due to its relatively low solution viscosity and high CS as well as FS. Effects of polymer content, P/L ratio, tartaric acid and initiator concentration were significant. During aging, the cement showed a constant increase in CS for up to 1 month and then kept constant for up to 3 months. Conclusions This study developed a novel amino acid modified zinc/calcium polycarboxylate cement system. This system was 85% higher in CS, 98% higher in DTS and 183% higher in FS, compared to Durelon.