Evaluation of SMART technique using Nano-silver fluoride and Silver Diamine Fluoride; evaluation of tooth discoloration and shear bond strength in primary molars

The aim of this study was to evaluate the shear bond strength and tooth discoloration of resin-modified glass ionomer cement (RMGIC) and high-viscosity glass ionomer cement (HGIC) restorations in primary teeth treated with either nano-silver fluoride (NSF) or silver diamine fluoride (SDF). Sixty-six primary molars with dentin caries were randomly assigned to six groups of 11 teeth each: two NSF-treated groups (one RMGIC, one HGIC) and two SDF-treated groups (one RMGIC, one HGIC). Two additional control groups received direct RMGIC and HGIC restorations, respectively. All samples were tested for tooth discoloration using a spectrophotometer before and after the thermocycling aging process (20,000 cycles). Shear bond strength was compared between the groups. Kruskal-Wallis test with a P-value of < 0.05 was used for statistical significance. The samples treated with SDF and restored with RMGIC exhibited the highest ΔE value (mean ± standard deviation (SD) of 8.27 ± 6.51). In contrast, the samples treated with NSF and restored with RMGIC demonstrated the lowest ΔE value (mean ± SD of 1.45 ± 0.77). No statistically significant differences were found between the groups in the shear bond strength test. NSF provided a better color masking effect compared to SDF when using RMGIC without visible black stains through the restoration. Additionally, neither NSF nor SDF affected the shear bond strength of either type of restoration applied to them. NSF may be preferred over SDF in cases where aesthetics is a priority, with similar bond strength and enhanced color matching.