Effect of decontamination and cleaning on the shear bond strength of high translucency Zirconia

Abstract

(1) Background: This study evaluated the bonding performance of high translucency zirconia after diverse surficial decontamination and cleaning procedures. (2)Methods: High translucency zirconia (Lava™ Esthetic) specimens (2.0 mm × 20 mm × 10 mm) were exposed to different surface treatments prior to bonding to CoCr cylinders (d = 5 mm, height = 3 mm). All surfaces were sandblasted (40 µm aluminum oxide, 2 bar) and treated with alcohol (al), saliva (s), saliva + water (sw), or saliva + NaOCl + water (sn) before bonding was performed with the following adhesive luting systems: RelyX™ Unicem 2 (RX), Scotchbond™ Universal (SBU) + RelyX™ Ultimate (RU) orMonobond Plus (MP) +Multilink® Automix (ML). After 24 h, thermocycling (TC:12,000 × 5 °C/55 °C) and 90 days of storage at 37 °C in distilled water, the shear bond strength (SBS) was evaluated according to ISO/TS 11,405:2015. Failure modes along bonding areas were characterized. Means and standard deviations (n = 10 per group) were determined and statistically analyzed with one-way ANOVA/Bonferroni (α = 0.05). (3) Results: The SBS after 24 h varied between 3.5 (sRX) and 69.4MPa (snMP +ML). Values from 0 (sRX) to 70.3MPa (swRX) were found after TC. Data after 90 days of storage showed the lowest values for sRX (0 MPa) and the highest values for alSBU + RU (75.5MPa). Adhesive failure was noted at all aging conditions. (4) Conclusions: SBU + RU or RX andMP +ML including saliva decontamination of the ceramic surface with water or NaOCl + water allow efficient bonding to LavaTM Esthetic.