29 - Influence of Bromelain and Biosilicate on Adhesive Bond Strength

Abstract

This study evaluated the effect of bromelain associated with Biosilicate on the bond strength (BS) of composite restorations to sound and caries-affected dentin. 360 sound human molars were selected, and occlusal cavities (6 mm×6 mm x 3 mm) were prepared using carbide burs. Half of them were submitted to cariogenic challenge with Streptococcus mutans strain ATCC25175. All the teeth were separated into nine groups (n = 20), according to the treatment received before the adhesive system (Single Bond Universal, 3 M ESPE): Control group Adhesive System (two coats in self-etch mode); CHX group 0,12% chlorhexidine; NaOCl group 5% sodium hypochlorite; Bio group 10% Biosilicate; Br5 group - 5% bromelain; Br10 group - 10% bromelain; Br5Bio group 5% bromelain + 10% Biosilicate; Br10Bio group 10% bromelain + 10% Biosilicate; NaOClBio group 5% sodium hypochlorite + 10% Biosilicate. After restorative procedures (Filtek Z350XT, 3 M ESPE), the samples were sectioned into sticks, separated, and stored in distilled water at 37 C for 24 h. After that, the sticks were submitted to microtensile test (0.5 mm/min). Data were analyzed using 2-way ANOVA and Bonferronis test (p <.05). The fracture pattern was observed with digital microscope (VH-M100). The caries-affected dentin presented higher BS (p <.05) than the sound substrate under control conditions and when the surface was treated with Biosilicate. Among the sound samples, there was no difference (p >.05), regardless of the treatment employed. In the caries-affected samples, Control and Br10 groups resulted in higher (p <.05) BS than Br5Bio group, with no difference (p >.05) between them. Br10 group also demonstrated higher values (p <.05) than Br10Bio group. The other groups showed no difference (p >.05). Both substrates presented higher incidence of non-adhesive fractures irrespective of the treatment. The pre-treatments with bromelain and bioactive glass-ceramic can affect the bond strength of composite restorations to sound and caries-affected dentin.