Effect of nanosilver fluoride versus silver diamine fluoride on shear bond strength and color change of resin-modified glass ionomer cement bonded to artificial dentin caries: an in-vitro study

Abstract Background Nanosilver fluoride (NSF) has emerged as a promising alternative to silver diamine fluoride (SDF), addressing its major drawback of tooth discoloration. Incorporating silver nanoparticles, NSF retains the advantageous preventive, antimicrobial and remineralizing characteristics of SDF without causing staining. This study aimed to investigate the effect of nanosilver fluoride versus silver diamine fluoride pretreatment on shear bond strength and color of resin-modified glass-ionomer cement (RMGIC) to caries-affected dentin and the impact of thermocycling on shear bond strength. Methods Forty-eight primary molars with artificially demineralized dentin were assigned to three groups: Group A (control, bonded with RMGIC), Group B (SDF treatment before RMGIC), and Group C (NSF treatment before RMGIC). Each group was subdivided into two subgroups 8 samples each; in subgroup 1 (non-aged) specimens underwent shear bond strength testing, in subgroup 2 (aged) baseline shade following RMGIC restoration was recorded, then specimens were subjected to 5000 cycles thermocycling prior to shade re-evaluation, color change assessment, and shear testing. Continuous data were presented as mean and standard deviation values. They were examined for normality and variance homogeneity by Shapiro-Wilk and Levene tests. Color change was tested with one-way ANOVA and Tukey’s post hoc, and bond strength with two-way ANOVA. The significance level was set at p < 0.05 for all tests. Results In non-aged subgroups, NSF demonstrated the highest bond strength, that was significantly higher than the control (p < 0.001), but nonsignificant when compared with SDF group; SDF exhibited insignificantly higher values as opposed to control. In aged subgroups, SDF had insignificantly higher values than NSF, and both were significantly higher than control (p < 0.001). Non-aged samples showed significantly higher bond strengths to aged samples across all groups. NSF group showed the lowest value of color change (ΔE00) (3.28 ± 0.75), followed by control with an insignificant difference (3.34 ± 1.09), SDF exhibited the highest value with a significant difference to other groups (5.03 ± 1.03). Conclusion NSF pretreatment resulted in shear bond strength of RMGI to caries-affected dentin comparable to SDF, while yielding significantly less color change after thermocycling. These results suggest NSF as a potential alternative to SDF, highlighting the need for further clinical validation.