Durability of Bonds between Luting Cements and High-Gold-Content Alloy

Objective: This study determined the long-term bond strength of various luting cements to high-gold-content alloy.Materials and Methods: High-gold-content alloy (Portadur P4; Wieland, Germany) specimens (Ø = 10 mm, h = 1 mm) were fabricated. Bonding substrates were placed into plastic rings and embedded with slow-polymerizing epoxy resin. Material surfaces were ground sequentially to 600-grit using SiC sandpaper. The surface of all specimens were 100 microns Al2O3 abraded at 2.8 bar, 10 s at 10 mm distance. Following luting cements were tested: PermaCem (DMG), RelyX ARC (3M ESPE), Panavia F (Kuraray), Nexus 2 (Kerr), Calibra (Dentsply DeTrey) and RelyX Unicem (3M ESPE). Eight specimens per group were fabricated: Group (A) was aged and tested after 150 day 37°C water storage; Group (B) 150 day at 37°C water storage, then thermocycled (37.500X, 5-55°C). Shear loading tests were performed using a universal testing machine at a constant crosshead speed of 0.5 mm/min. Two-way ANOVA of variance was used to analyze the data (α=0.05). Results: Significant differences were found between all main effects (all p Parole chiave: luting cement, bond durability, artificial aging