title: Novel amino acid modified zinc polycarboxylates for improved dental cements.
abstract: 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.
  
  
  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 degrees 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.
authors.affiliation: Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University, Indianapolis, IN 46202, USA. dxie@iupui.edu
authors.forename: Dong
authors.initials: D
authors.lastname: Xie
authors.forename: Mona
authors.initials: M
authors.lastname: Faddah
authors.forename: Jong-Gu
authors.initials: JG
authors.lastname: Park
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D019245:Compressive Strength; D018698:Glutamic Acid / Q000737:chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D018583:Pliability; D011076:Polycarboxylate Cement / Q000138:chemical synthesis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013644:Tartrates / Q000737:chemistry; D013997:Time Factors; D014783:Viscosity; D015032:Zinc / Q000737:chemistry; D015091:beta-Alanine / Q000737:chemistry
chemical_list: D000596:Amino Acids; D008689:Methacrylates; D011076:Polycarboxylate Cement; D013644:Tartrates; D015091:beta-Alanine; D018698:Glutamic Acid; C005044:hydroxyethyl methacrylate; D015032:Zinc; D002118:Calcium; C029768:tartaric acid