Polyphenol-enriched extract incorporated into a total-etch adhesive system: Effect on water sorption and solubility, extract compound release and dentin enzymatic activity over time

This study evaluated water sorption, solubility and compound release of 2.5% Arrabidaea chica polyphenolic extract (Ac) incorporated into the primer of a total-etch adhesive system; and dentin metalloproteinases inhibition when using Ac as dentin pretreatment in aqueous solution or incorporated either into acid or adhesive system primer. Adhesive system discs (Adper Scotchbond Multipurpose/3 M Oral Care/SB) with and without Ac were prepared (n = 10) for water sorption, solubility and compound release. Concentration of extract released in water was evaluated at 1, 3, 7, 14, 28, 36 days immersion. Dentin-resin interfaces were prepared for zymography analysis (control (SB); dentin pretreatment with water; dentin pretreatment with 2.5% Ac aqueous solution; Ac incorporated into phosphoric acid; Ac incorporated into SB primer) and assessed for in situ zymography tests after 24-h and 6-month storage. Primer incorporated with Ac showed lower water sorption (p = 0.0102) and solubility (p = 0.0065) than non-incorporated. Ac release was observed at third and seventh days (p = 0.0031). There was no significant difference between treatments (p = 0.4298) either immediately or after 6 months regarding relative fluorescence unit means among groups, and these means decreased after 6 months (p