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

Abstract

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. 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. 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. 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.