IADR Abstract Archives
Investigation of Apatite Formation Ability of Novel RMGIC and GIC
Objectives: To evaluate the capability of experimental resin modified glass ionomer cements (RMGICs) and glass ionomer cements (GICs), with and without substituting 10%wt bioactive glass, to form apatite on immersion in media similar to the oral environment.
Methods: Two synthetic RMGICs and GICs with varying phosphorus content in ionomer glass (0.5P2O5, 0.75P2O5), with and without the addition of 10wt% experimental sodium-free bioactive glass, and a commercial restorative material (ACTIVA™ BioACTIVE-RESTORATIVE™), were examined. Set cement disks (n=3) were immersed in AS for 2-weeks, 1-month and 3-months. 31P Magic-Angle-Spinning-Nuclear-Magnetic-Resonance (31P MAS-NMR), Fourier-transform-infrared spectroscopy (FTIR), X-ray-diffraction (XRD) and Scanning-Electron-Microscopy with energy dispersive X-ray-spectroscopy (SEM/EDX) were used to determine the ability of these cements to form apatite.
Results: 31P MAS-NMR, FTIR, XRD of the home-made-compositions with low phosphorus content displayed evidence of apatite formation, which increased over time. On the contrary, the commercial material showed no signs of apatite formation even up to 3-months immersion period. SEM images demonstrated a drastic change on the surface of the cement disks after immersion.
Deposition of a calcium phosphate layer was confirmed by the relative increase in phosphate (P) and calcium (Ca) concentration over the nominal concentration of aluminium (Al) and silicon (Si) with ageing of cements, as seen by EDX.
Conclusions: The results demonstrate that experimental RMGICs and GICs are capable of forming apatite on immersion in AS, with time. The potential of RMGICs to re-mineralise was higher than what was observed with GICs under the same conditions.
Methods: Two synthetic RMGICs and GICs with varying phosphorus content in ionomer glass (0.5P2O5, 0.75P2O5), with and without the addition of 10wt% experimental sodium-free bioactive glass, and a commercial restorative material (ACTIVA™ BioACTIVE-RESTORATIVE™), were examined. Set cement disks (n=3) were immersed in AS for 2-weeks, 1-month and 3-months. 31P Magic-Angle-Spinning-Nuclear-Magnetic-Resonance (31P MAS-NMR), Fourier-transform-infrared spectroscopy (FTIR), X-ray-diffraction (XRD) and Scanning-Electron-Microscopy with energy dispersive X-ray-spectroscopy (SEM/EDX) were used to determine the ability of these cements to form apatite.
Results: 31P MAS-NMR, FTIR, XRD of the home-made-compositions with low phosphorus content displayed evidence of apatite formation, which increased over time. On the contrary, the commercial material showed no signs of apatite formation even up to 3-months immersion period. SEM images demonstrated a drastic change on the surface of the cement disks after immersion.
Deposition of a calcium phosphate layer was confirmed by the relative increase in phosphate (P) and calcium (Ca) concentration over the nominal concentration of aluminium (Al) and silicon (Si) with ageing of cements, as seen by EDX.
Conclusions: The results demonstrate that experimental RMGICs and GICs are capable of forming apatite on immersion in AS, with time. The potential of RMGICs to re-mineralise was higher than what was observed with GICs under the same conditions.