Commercial Silver Diamine Fluoride (SDF) Products on Caries Lesion Progression in Primary Enamel: An In Vitro Study

Purpose: Evidence has shown that silver diamine fluoride (SDF) at 30-38% has the potential to control and revert caries lesions. However, SDF can be found at lower concentrations on the market. In this study, we evaluated the effect of different commercially available SDF products on the progression of non-cavitated caries lesion in primary teeth assessed by a pH-cycling model. Materials and Methods: Subsuperficial caries lesions were formed in primary teeth using a demineralising solution for 96 h. Demineralised samples were randomly allocated to the following groups (n = 12/group): (G1) Negative Control, deionised water; (G2) Cariostatic, Inodon; 10%* SDF; (G3) Cariestop, Biodynamics, 12%* SDF; (G4) Cariostal, Iodontec, 16%* SDF; (G5) Cariestop, Biodynamics, 30%* SDF (*concentrations declared in the label). Products were applied according to the manufacturer's recommendation and reapplied after 7 days. Samples were exposed to a pH-cycling model for 14 days. After the cycle was completed, samples were sectioned, analysed by polarised light microscopy, and lesion depth was estimated as indicator of caries lesion progression. Groups were compared by multiple comparisons test (p < 0.05). Results: The negative control group exhibited the greatest lesion depth. All SDF products reduced the caries lesions depth and differed from the negative control. It was a trend observed (G1>G2>G3>G4), but no statistical differences among G3, and G5, and between G4 and G5 were observed for lesion depth. Conclusion: The tested SDF products reduced the depth of non-cavitated carious lesions in primary enamel. Although SDF products with declared concentrations between 12% and 30% (G3, G4, and G5) demonstrated a similar lesion depth in primary enamel, the effect of the concentration remains unclear.