Effect of the use of bromelain associated with bioactive glass-ceramic on dentin/adhesive interface

Objectives To evaluate the effect of bromelain associated with Biosilicate on the bond strength (BS) of a universal adhesive system to sound (SD) and caries-affected dentin (CAD), and on the proteolytic activity. Materials and methods Cavities were prepared in 360 molars, half submitted to cariogenic challenge. Teeth were separated into groups (n=20): Control–No treatment; CHX–0.12% chlorhexidine; NaOCl–5% sodium hypochlorite; Br5%–5% bromelain; Br10%–10% bromelain; Bio–10% Biosilicate; NaOClBio–NaOCl+Bio; Br5%Bio–Br5%+Bio; Br10%Bio–Br10%+Bio. Following treatments, the adhesive system was applied, and cavities were restored. Samples were sectioned into sticks and stored at 37 °C for 24 h, 6 months, and 1 year. Microtensile BS (2-way ANOVA, Bonferroni’s test, α=0.05), fracture patterns (SEM), and adhesive interfaces (TEM) were evaluated. Bacterial collagenase assay and in situ zymography were performed. Results In CAD, Br10% presented higher BS ( p =0.0208) than Br5%Bio. Br5% presented higher BS ( p =0.0033) after 6 months than after 24 h; and association of treatments, higher BS ( p <0.05) after aging than after 24 h. Mixed fractures were the most prevalent. Association of treatments promoted a more uniform hybrid layer with embedded Bio particles. Experimental groups presented lower ( p <0.0001) relative fluorescence units than Control. Bromelain, associated or not with Bio, showed collagenolytic degradation. Conclusions Bromelain associated with Biosilicate did not affect the BS to SD. In CAD, Br5%Bio decreased immediate BS but had no long-term influence. This association decreased the proteolytic activity. Clinical relevance Bromelain and Biosilicate may enhance the longevity of adhesive restorations by inhibiting endogenous proteases.