Bromelain and Bioactive Glass-Ceramic Affect the Bond Strength of Carious-Dentin

Objectives: This study evaluated the effect of bromelain and Biosilicate on the bond strength (BS) of composite restorations to sound (SD) and caries-affected dentin (CAD).
Methods: 360 sound human molars were selected, and occlusal cavities (6mm x 6mm x 3mm) were prepared using carbide burs. Half of them were submitted to cariogenic challenge with Streptococcus mutans ATCC25175. All the teeth were separated into nine groups (n=20), according to the treatment received before the adhesive (Single Bond Universal, 3MESPE): Control group-Adhesive (two coats, 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 restorations (Filtek Z350XT, 3MESPE), the samples were sectioned into sticks, separated, and stored in distilled water at 37°C for 24h or 6 months. After that, the sticks were submitted to microtensile test (0.5mm/min). Data were analyzed using 2-way ANOVA and Bonferroni’s test (p<.05). Fracture patterns were observed with digital microscope (VH-M100).
Results: After 24h CAD presented higher BS (p<.05) than SD under control conditions, and after 24h and 6 months when treated with Biosilicate (p<.05). In SD, there was no difference (p>.05) after 24h, regardless of the treatment. After 6 months, NaOCl revealed higher BS than Bio (p<.05). In CAD, after 24h Control and Br10 resulted in higher (p<.05) BS than Br5Bio, with no difference (p>.05) between them. Br10 also demonstrated higher values (p<.05) than NaOClBio. After 6 months, there was no difference (p>.05). SD treated with NaOCl associated or not to Biosilicate and CAD treated with CHX, NaOCl, Br5, and the association of treatments showed higher BS (p<.05) after 6 months than after 24h. Both substrates presented higher incidence of non-adhesive fractures irrespective of the treatment or aging.
Conclusions: The bromelain and Biosilicate can affect the BS of CAD.