Surface treatments of a glass-fiber reinforced composite: Effect on the adhesion to a composite resin

To compare the effect of different surface treatments (pre-treatments and bonding agents) on the bond strength between glass-fiber post and composite resin, and the topographic alterations of the treated post surface. Thirty-six glass-fiber blocks (12mm×10mm×8mm) were specifically manufactured for this study and randomly assigned into 12 groups considering two factors: ‘pre-treatments’ (–cleaning with 70% alcohol; air-abrasion with silica-coated aluminum oxide particles; 35% hydrogen peroxide) and type of ‘bonding agent’ (no bonding agent; application of Monobond Plus; RelyX Ceramic Primer; Single Bond Universal). After that, 6 cylindrical templates (1mm high×1mm Ø) were fixed on each block, filled with composite resin (n=18) and light-cured. Specimens were stored under 37°C for 24h and microshear tests (wire loop Ø=0.2mm) were performed. Topographic, roughness and failure analyses were also performed. Different surface pre-treatments led to different topographic and roughness alterations; a higher surface alteration was noted after silica particles air-abrasion, while a slight surface alteration in the hydrogen peroxide group and a smooth pattern were observed in the cleaning group. The factors ‘pre-treatments’ (p