Durability of the resin bond strength to zirconia ceramic after using different surface conditioning methods.

OBJECTIVES The purpose of this in vitro study was the evaluation of the bond strength and its durability of two composite resins to zirconia ceramic after using different surface conditioning methods. METHODS Plexiglas tubes filled with composite resin were bonded to zirconia ceramic discs (Cercon) which were either in their original state as supplied by the manufacturer only cleaned in isopropanol or were cleaned with an air-powder-water spray with sodium hydrocarbonate solution or were air abraded (50 microm Al(2)O(3)). Groups of 20 specimens each were bonded either with a conventional composite resin (Variolink II) or with a phosphate monomer (MDP)-containing resin (Panavia F) to the ceramic discs. Subgroups of 10 bonded specimens were stored in distilled water (37 degrees C) for either 3 days or for 150 days. Additionally, the 150 days specimens were thermal cycled 37,500 times. Statistical analyses were conducted with the Wilcoxon rank sum test adjusted by Bonferroni-Holm. RESULTS The initial tensile bond strength (TBS) for Variolink II ranged from 9.0 to 16.6 MPa and were significantly lower (p< or =0.05) than for Panavia F ranging from 18.7 to 45.0 MPa. Air abrasion resulted in significantly higher TBS (p< or =0.01) than the two other surface conditioning methods. After 150 days storage, only the air abraded specimens bonded with Panavia F showed high bond strengths of 39.2 MPa, whereas most other specimens debonded spontaneously or showed very low bond strengths. SIGNIFICANCE The use of the MDP-containing composite resin Panavia F on air abraded zirconia ceramic can be recommended as promising bonding method.