Long-term bond strength of ormocer-based resin composites using a universal adhesive used in different adhesive strategies.

Purpose: To evaluate over time the bond strength to dentin of different resin composites (RBCs) associated with the universal adhesive system applied with self-etching or total-etching strategies.

Methods: 60 human third molars were obtained, randomly divided into experimental groups (n= 10) according to RBCs: methacrylate-based nanofilled (Z350 XT); low-viscosity Ormocer-based bulk-fill (Admira Fusion X-base Universal); or high-viscosity Ormocer-based bulk-fill composite (Admira Fusion X-tra). The adhesion procedure was performed using a universal adhesive (Futurabond U) applied in self-etching or total-etching mode.