EVALUATION OF DIFFERENT SURFACE CONDITIONING METHODS ON THE BOND STRENGTH OF ZIRCONIA CERAMIC TO A RESIN CEMENT

Surface conditioning methods used for resin bonding to conventional silica base dental ceramics are not dependable for zirconium ceramic. The aim of this study was to evaluate the effect of different surface conditioning methods on the shear bond strength of zirconia ceramic to resin cement. Twenty eight Zirconia ceramic specimens were fabricated from (IPS e.max Zir CAD), and randomly assigned to four groups (n=7).Each group was subjected to the following surface treatments: Control (no treatment), sandblasting with 110 µm aluminum oxide, Silica coating and silanization (CoJet system), and Nd: YAG laser irradiation. A composite resin discs were fabricated and bonded to the treated ceramic surfaces using resin luting agent (Panavia F 2.0) and stored for 24 hours in distilled water at 37 OC. Specimens then subjected to thermocycling for 1000 cycles between 5O C and 55O C with a 30 s dwell time. All specimens were subjected to shear bond strength test by a universal testing machine at a crosshead speed of 0.5 mm/minute. The shear bond strength values were analyzed with ANOVA to compare between groups using SPSS software .The level of significance was 0.05. Results obtained showed that silica coating and silanization (CoJet system) is an effective method for achieving an acceptable bond between zirconia and resin cement. The use of Nd: YAG laser enhance the bond strength between the zirconia and resin cement.