Influence of diode laser treatment and casein phosphopeptide-amorphous calcium phosphate paste on eroded root dentin

INTRODUCTION: It is still unclear whether the pretreatment for dentin hypersensitivity can interfere with the adhesive–dentin bonding strength. This study aimed to evaluate in vitro the effect of pretreatment with a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and diode laser on the shear bond strength of the etch-and-rinse adhesive system in the adhesive–dentin interface. MATERIALS AND METHODS: Seventy-five bovine root specimens were randomly divided into five experimental groups (n = 15). Samples were eroded by six cycles of immersion in hydrochloric acid solution (0.01M; pH = 1.2) for 20 s each, at 45 min intervals, and treated with: G2 – no treatment, G3 – CPP-ACP, G4 – diode laser (970 nm), and G5 – CPP-ACP + Diode laser. After treatments, the morphology of the specimens was analyzed. RESULTS: The fracture mode of each group was evaluated after restoration with composite resins in the treated area. Data were analyzed by the one-way ANOVA and Tukey's test (P < 0.05). G3 showed the highest values for shear bond strength; there was no significant difference among G1, G3, and G5 (P > 0.05). The adhesive fracture was predominant for all groups. CONCLUSION: The use of desensitizers containing CPP-ACP, associated or not with a diode laser, increased the bond strength of the etch-and-rinse adhesive system on eroded root dentin.