title: Early reaction kinetics of contemporary glass-ionomer restorative materials.
abstract: OBJECTIVE
  To investigate polyalkenoate reaction rates in conventional glass-ionomer cement (GIC) and resin-modified glass ionomer (RMGI) restorative materials using infrared spectroscopy.
  
  
  METHODS
  Nine conventional GIC and six RMGI restorative materials were prepared according to manufacturer's directions and placed on a FTIR (Fourier transform infrared spectroscopy) diamond ATR (attenuated total reflectance) surface. FTIR spectra (700 to 1800 cm-1) were obtained each minute for 3 h. VLC specimens were light polymerized after 1 min; at 5 min, all samples were covered with gauze saturated with deionized water. Polyalkenoate reaction was determined by measuring area growth (Å/cm-1) between 1375 and 1500 cm-1. Mean peak areas were determined at 5, 15, 30, 90, and 180 min and compared using ANOVA (p = 0.05) RESULTS: For all RMGI materials, VLC polymerization inhibited the polyalkenoate reaction rate. Compared to conventional GIC, RMGI materials demonstrated less polyalkenoate reaction. Compared to dark curing, RMGI light polymerization significantly inhibited the polyalkenoate reaction rate.
  
  
  CONCLUSIONS
  The addition of resin components to glass-ionomer products significantly retards and impedes the polyalkenoate reaction. The polyalkenoate reaction rate of RMGI products was significantly lower than that of self-curing GIC restorative materials. Furthermore, light activation of RMGI products further retards the polyalkenoate rate. When clinicians require the therapeutic benefit of a polyalkenoate product, perhaps a conventional GIC restorative product should be the first material of choice.
authors: Howard W
authors: HW
authors: Roberts
authors: David W
authors: DW
authors: Berzins
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D016722:Cermet Cements / Q000737:chemistry; D055598:Chemical Phenomena; D003188:Composite Resins / Q000737:chemistry; D003624:Darkness; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D055115:Light-Curing of Dental Adhesives; D008298:Maleates / Q000737:chemistry; D058105:Polymerization; D019279:Resin Cements / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D016722:Cermet Cements; D003188:Composite Resins; C079765:Fuji II LC cement; C439808:Fuji IX GP Fast; D005899:Glass Ionomer Cements; C454800:Ketac-Molar Quick; D008298:Maleates; C467912:Photac-Fil Quick; D019279:Resin Cements; D012117:Resins, Synthetic; C084550:Vitremer; C110712:ketac-molar; D014867:Water; C039733:Chemfil; C040964:Ketac-Fil