Objective

To evaluate the effect of SDF-based treatments following delayed bonding and surface treatment approaches on resin-dentin bonding efficiency of a universal adhesive under different application modes.
Methods

Mid-coronal dentin surfaces from sound third molars were randomly treated with 38% silver diamine fluoride (SDF) and/or additionally with potassium iodide (SDF/KI). Untreated dentin served as control. SDF-treated teeth were assigned to groups according to surface treatment approaches (air-abrasion and water rinsing), the application mode of a mild universal adhesive (etch-and-rinse or self-etch) and delayed bonding (immediate, 7, 15 or 30 days). Microtensile bond strength (n = 5), SEM analyses of hybrid layer formation and dentin etching patterns and dentin permeability were evaluated. Data were analyzed with factorial ANOVA.
Results

SDF-based treatments affected dentin bonding depending on application mode and surface treatment approaches (p<0.001). Etch-and-rinse bonding was not affected by SDF-based treatments (p<0.05), producing more homogenous hybrid layers. While dentin etching patterns of etch-and-rinse application were not affected by SDF-based treatments, self-etching presented limitations. Bond strength reductions of self-etched dentin were restored by silver-removal strategies containing a water-rinsing step (p<0.05). Delayed bonding additionally reduced dentin permeability (p<0.05), further decreasing with longer periods (p<0.05).
Conclusion

Although the negative effect of SDF-based treatments on resin-dentin bonding can be avoided by strategies incorporating water-rinsing before hybridization, delayed bonding brings additional advantages due to higher mineral deposition.
Clinical significance

While the etch-and-rinse technique avoids major bonding drawbacks to SDF-treated dentin, self-etch bonding requires removal of excess silver deposits before hybridization. Performing SDF-based treatments and dentin hybridization in separate sessions (>15 days apart) potentialize mineral deposition improving caries control and service life of composite restorations.