Influence of Surface Treatment on Resin Bond to Zirconia

Objectives: This study evaluated and compared the effect of different surface pretreatments on the bond strength of a new composite resin luting agent to zirconia.
Methods: A total of 72 cubic samples (3.4mm x 3.4mm x 3.4mm) were prepared from zirconia (Zirconoxide, Heraeus Kulzer) and divided into 6 test groups of 12 samples each. The zirconia samples then received different surface pretreatments and were labeled as control (CNT), grinding with 320 grit sand paper (GRD), grinding+30 second acid etching with 40% HF acid (AE30), grinding+60 second acid etching (AE60), sandblasting with 30-μm Al₂O₃ (SBL), and grinding with a YSGG laser energy (WaterLase iPlus, Biolase) (LAS). Cylindrical composite samples (2.1mm in diameter, 3mm in height) were then bonded to primer treated zirconia surfaces with a new composite resin luting agent (Panavia V5, Kuraray) with an alignment apparatus. A load of 1000g was applied to the composite cylinders for 5 minutes prior to irradiating them 40s from three sides for a total of 120s. The samples were kept in water at 37°C for 24 hours. Shear bond strength was determined at a crosshead speed of 0.5 mm/minute. Data were analyzed with ANOVA & Tukey’s HSD test.
Results: All surface treatment methods showed similar bond strength values, except for LAS, which, however, was not different from AE60 or the control (P>0.05) (table 1).
Conclusions: Surface treatment influences resin bond strengths to zirconia. Tested pretreatment methods revealed similar results, except for laser treatment.