Evaluation of resin/dentin bonded interfaces formed by different adhesive strategies and exposed to NaOCl challenge

This study evaluated the importance of encapsulated collagen on resin/dentin interface created by different adhesive strategies. Composite build-ups were bonded to dentin using one of the following adhesive systems: Scotchbond Multi-Purpose (SBMP), Adper Scotchbond 2 (SB2), Clearfil SE (CSE) and Scotchbond SE Plus (SBSE), and cut into non-trimmed dentin–composite beams. Half of those beams were deproteinized using 10% NaOCl for 1 h and the other half was stored in water. Beams were pulled to failure and data were statistically analyzed by a two-way ANOVA and Tukey for multi-comparison test (α=0.05). Additional dentin disks were stained with Masson׳s trichrome acid and processed with light microscopy in order to identify the exposed collagen zones. All groups showed a significant reduction on bond strength after proteolytic challenge (p<0.05). Adhesive systems were ranked in the following order: SBMP>SB2=CSE>SBSE (p<0.05) for control and treated groups. Microscopy analysis showed different collagen exposed zones in relation with the adhesive strategy used. It can be concluded that collagen encapsulation affects the quality of bond interface, which is related to the adhesive system used.