Objective: This study aims to compare the effectiveness of two adhesives in bonding CAD/CAM composite resin (CS, Cerasmart 270, GC) prepared using two different sandblasting techniques to human dentin.
Materials and methods: Sixty human dentin samples were prepared and treated in etch-and-rinse mode with either the two-bottle G2-BOND Universal (GC) system (G2) or the one-bottle G-Premio BOND (GC) system (GP). CS cylinders were milled and sandblasted based on the alumina particles size used: 50 µm (-50) or 250 µm (-250). Therefore, four distinct groups were obtained: GP-50, G2-50, GP-250, G2-250. A primer (G-Multi PRIMER, GC) was applied on all CS samples before luting to the dentin with G-CEM Link Force (GC). Bond strength (SBS, Universal testing machine, cross-head speed 0.5 mm/min) was measured after 150 days of aging in water, 37°C. A one-way analysis of variance (ANOVA) was used to analyze the roughness, and a two-way ANOVA to analyze the SBS, (SPSSv26, IMB, α=0.05).
Results: Sandblasting with a 250 µm particle size created a rougher surface (p < 0.001) with an increased developed area. The G2-250 group showed the greatest SBS values, statistically higher than GP-250 (p = 0.002), while no statistically significant difference was observed in comparison with the other groups. Simple main effects analysis showed that adhesive had a significantly positive effect on SBS results (p = 0.025) while no significant effect was observed for the pretreatment (p = 0.707). Failure mode analysis showed exclusively mixed failures for the G2 group, indicative of robust adhesion, whereas the GP group exhibited mixed and adhesive failures.
Significance: The two-step adhesive G2 coupled with macro-sandblasting demonstrated a more robust adhesion.
Keywords: CAD-CAM; Dentin Adhesion; Nanoparticle-Filled Composite; Sandblasting.
Copyright © 2025 Elsevier Inc. All rights reserved.