IADR Abstract Archives
Essential Role of HEMA in Remineralisation of Resin-Based Cements
Objectives: This study aimed at monitoring the degree of apatite formation in a range of experimental RMGIC formulations following immersion in artificial saliva.
Methods: Novel RMGICs with relatively low phosphate content and different HEMA concentrations (30% and 15%), with and without substitution of the experimental glass (10wt%) with experimental sodium-free BAG, and different polyacrylic acid (PAA) concentrations (20%, 10% and 0%), were examined together with an experimental GIC and a commercial restorative material (ACTIVA™ BioACTIVE-RESTORATIVE™). Set cement disks (n=3) were immersed in artificial saliva (AS) for 2-weeks, 1-month, 3-months, 6-months, and 12-months. 31P Magic-Angle-Spinning-Nuclear-Magnetic-Resonance (31P MAS-NMR) and 19F MAS-NMR were used to determine the ability of these cements to form apatite. Controlled water absorption experiment was conducted up to 6 months in AS, to evaluate the impact of the materials’ hydrophilicity on apatite formation.
Results: 31P MAS-NMR and 19F MAS-NMR of the experimental compositions demonstrated evidence of increasing apatite formation over time. No significant difference in apatite formation was found between the experimental RMGICs and the different HEMA and PAA concentrations, while the hydrophilicity of experimental compositions had a limited effect. The substitution of 10wt% of the experimental glass with experimental BAG accelerated apatite formation. On the contrary, the commercial material showed no signs of apatite formation, at 12-months immersion in AS.
Conclusions: Experimental RMGICs and GICs formed apatite, following immersion in AS, with time. The potential of RMGICs to remineralise was higher than with GICs under the same circumstances. Presence of HEMA played a role in enhancing apatite formation within RMGICs. This could be beneficial to occlude microleakage at the tooth restoration interface and prevent secondary caries development.
Methods: Novel RMGICs with relatively low phosphate content and different HEMA concentrations (30% and 15%), with and without substitution of the experimental glass (10wt%) with experimental sodium-free BAG, and different polyacrylic acid (PAA) concentrations (20%, 10% and 0%), were examined together with an experimental GIC and a commercial restorative material (ACTIVA™ BioACTIVE-RESTORATIVE™). Set cement disks (n=3) were immersed in artificial saliva (AS) for 2-weeks, 1-month, 3-months, 6-months, and 12-months. 31P Magic-Angle-Spinning-Nuclear-Magnetic-Resonance (31P MAS-NMR) and 19F MAS-NMR were used to determine the ability of these cements to form apatite. Controlled water absorption experiment was conducted up to 6 months in AS, to evaluate the impact of the materials’ hydrophilicity on apatite formation.
Results: 31P MAS-NMR and 19F MAS-NMR of the experimental compositions demonstrated evidence of increasing apatite formation over time. No significant difference in apatite formation was found between the experimental RMGICs and the different HEMA and PAA concentrations, while the hydrophilicity of experimental compositions had a limited effect. The substitution of 10wt% of the experimental glass with experimental BAG accelerated apatite formation. On the contrary, the commercial material showed no signs of apatite formation, at 12-months immersion in AS.
Conclusions: Experimental RMGICs and GICs formed apatite, following immersion in AS, with time. The potential of RMGICs to remineralise was higher than with GICs under the same circumstances. Presence of HEMA played a role in enhancing apatite formation within RMGICs. This could be beneficial to occlude microleakage at the tooth restoration interface and prevent secondary caries development.