IADR Abstract Archives
Chemical, Biological, and Mechanical Properties of a Novel Glass Ionomer
Objectives: Degradation of the restorative-dentin hybrid layer through the activity of endogenous dentin enzymes such as matrix metalloproteinases (MMPs) is a major issue that leads to the failure of dental restorative treatments. Caredyne Restore (CR), a new glass ionomer cement (GIC) incorporating zinc, is the latest formulation to mitigate this issue. The purpose of this investigation is to evaluate the MMP inhibitory effect, the mechanical properties and biocompatibility of CR when compared to a non-zinc containing GIC, Fuji IX (FIX).
Methods: The enzyme inhibition effect of CR on MMP activity was evaluated using in-situ zymography to visualize the MMP activity in the GIC-dentin interface. Furthermore, an investigation into this novel GIC’s mechanical properties using dye-assisted confocal laser microscopy (CLSM) imagery to show the leakage and micropermeability across the interface. Both the in-situ zymography and CLSM observations were done immediately and after 7-days of acid-base challenge. Finally, the biocompatibility, cytotoxicity, cell morphology, and differentiation effects of the GIC eluates on rat dental pulp cells were examined. Multiple eluate concentrations were used in the cell tests and the assay measurements were conducted at 24 and 48h of incubation with test solutions, n=6.
Results: When compared to FIX, the MMP activity of the CR specimens was significantly lower. Leakage and permeability were also lower. Higher concentrations of CR eluate showed increased cytotoxicity, decreased cell proliferation, and morphological changes in cells, while lower concentrations of eluate showed no significant differences and no morphological changes when compared with non-zinc GIC.
Conclusions: The inclusion of Zn ions in GIC formulations may improve the quality of dental restorations, especially in lesions where the dentin matrix is susceptible to enzymatic degradation.
Methods: The enzyme inhibition effect of CR on MMP activity was evaluated using in-situ zymography to visualize the MMP activity in the GIC-dentin interface. Furthermore, an investigation into this novel GIC’s mechanical properties using dye-assisted confocal laser microscopy (CLSM) imagery to show the leakage and micropermeability across the interface. Both the in-situ zymography and CLSM observations were done immediately and after 7-days of acid-base challenge. Finally, the biocompatibility, cytotoxicity, cell morphology, and differentiation effects of the GIC eluates on rat dental pulp cells were examined. Multiple eluate concentrations were used in the cell tests and the assay measurements were conducted at 24 and 48h of incubation with test solutions, n=6.
Results: When compared to FIX, the MMP activity of the CR specimens was significantly lower. Leakage and permeability were also lower. Higher concentrations of CR eluate showed increased cytotoxicity, decreased cell proliferation, and morphological changes in cells, while lower concentrations of eluate showed no significant differences and no morphological changes when compared with non-zinc GIC.
Conclusions: The inclusion of Zn ions in GIC formulations may improve the quality of dental restorations, especially in lesions where the dentin matrix is susceptible to enzymatic degradation.