effect of incorporating bioactive glass filler in resin infiltrant on the microhardness of demineralized enamel

Objective: this study aimed to evaluate the effect of incorporating different concentrations of 45s5 bioactive glass (bag) as a filler into a resin infiltrant on the microhardness of demineralized enamel.methods: forty bovine enamel samples were subjected to a ph-cycling protocol to induce artificial caries lesions. the teeth were randomly assigned to four groups (n = 10), based on the remineralizing treatment applied: g1: the commercial icon® resin infiltrant (control); g2 and g3: experimental resin infiltrants containing 5 wt% (g2) and 2 wt% (g3) 45s5 bioactive glass; and g4: a filler-free resin infiltrant. vickers microhardness was measured at depths of 50, 100, and 150 µm. the data weer analyzed using two-way anova (α=0.05).results: both the type of resin infiltrant and lesion depth significantly influenced enamel microhardness (p<0.001). icon® consistently demonstrated the highest microhardness, significantly outperforming the other groups at all evaluated depths (p < 0.05). microhardness increased with depth in all groups, with significant differences observed between 50, 100, and 150 µm depths (p < 0.05). incorporation of bioglass® 45s5 into the resin infiltrant was effective in enhancing microhardness, as compared to unfilled resin. the 5% concentration of bioglass® 45s5 also caused a significant rise in microhardness compared to the 2 wt% at 50 µm depth (p<0.05).conclusions: the commercial resin infiltrant (icon®) consistently achieved the highest microhardness at all depths. the incorporation of bioglass® 45s5 enhanced microhardness, with the 5 wt% group exhibiting superior performance compared with the 2 wt% group and the filler-free control.