Resin bond strength to translucent zirconia: A 2-year follow-up

The aim of this study is to evaluate the effect of aging on resin bond strength to translucent zirconia treated with the most clinically used bonding procedures. Monolithic translucent zirconia-based ceramic (3Y-TZP) blocks were surface treated using airborne-particle abrasion with alumina particles (AP) or silica-coated alumina particles (SC) then bonded to resin composite blocks using a resin cement system containing a silane coupling agent and an adhesive with a phosphate (MDP) monomer. Bar-shaped specimens (bonding area: 1 mm ²) were fabricated (n = 30) and stored in 37 °C distilled water for the following time before testing: 7 days (SCI and API); 1 year (SC1 and AP1); and 2 years (SC2 and AP2). Specimens were loaded to failure under tension using an Instron testing machine. Microtensile bond strength (σ _f ) data was statistically analyzed using Weibull distribution, analysis of variance (ANOVA) and Tukey tests (α = 0.05). Failures were evaluated using fractographic principles. Mean σ _f values significantly decreased after 2 years of water storage (SC2 and AP2) (p < 0.05), although there was no difference in the Weibull modulus. All specimens failed cohesively within the adhesion zone at the zirconia-cement adhesive interface.