Shear Bond Strength of Different Restorative Materials to Primary Tooth Dentin Treated with Silver Diamine Fluoride

Purpose: To investigate shear bond strength (SBS) of three restorative materials on primary dentin after silver diamine fluoride (SDF) application. Methods: Thirty primary teeth were randomized into three groups of 10 teeth. Each tooth was split mesiodistally and randomized into experimental (artificial caries plus SDF) and control (sound dentine without SDF) groups. Glass ionomer cement (GIC), resin-modified bioactive resin (ACTIVA), and composite resin (CR) restorations were tested for SBS and mode of failure (MF). Results: All SDF groups exhibited significantly lower SBS compared to the control (CR: P=0.001; ACTIVA: P=0.001; GIC: P=0.004). For the SDF group, the compa-rison of materials was statistically significant (P=0.006); posthoc tests showed significance only between CR and ACTIVA (P=0.009) and between ACTIVA and GIC (P=0.020). The lowest mean value was obtained for ACTIVA (1.4 MPa) and the highest mean value was obtained for CR (3.3 MPa). For the control group, Welch's F test was statistically significant (P=0.044), but all posthoc tests were not. For MF, SDF exhibited a significantly greater percentage of adhesive failures with ACTIVA and CR than with GIC. In the control group, a mixed MF was more dominant with no significant differences. Conclusion: The SDF group had significantly lower SBS.