Nourhan A. El-Maghrabi, Yehia S. Aboushady And Seham A. Hanafy,

ABSTRACT
Objective: The Aim Of This Study Was To Evaluate The Effect Of Sintering, Surface Treatment And Different Types Of Cements On The Shear Bond Strength Of Zirconia-reinforced Lithium Silicate Restorations.

Materials and Methods: Forty Specimens Of Zirconia-reinforced Lithium Silicate Of 10 Mm In Diameter And Thickness Was 2mm Were Randomly Divided Into Two Groups (N=20), One Group Was Cut And One Surface Polished While The Other Group Was Cut And Sintered. Each Group Was Randomly Subdivided According To The Method Of Surface Treatment; One Group Was Sandblasted While The Other Group Was Sandblasted And Etched With Hydrofluoric Acid And Luted To Composite Cylinders By Using Two Types Of Resin Cements: A Dual-curing (Calibra Resin Cement) And Dual-curing (Panavia V5) Adhesive Systems According To The Manufacturer?s Instructions. Specimens Were Thermo-cycled Between 5?C And 55?C In Water For 500 Cycles, Shear Bond Strength Test Was Performed In A Universal Testing Machine At 0.5 Mm/min Until Failure Occurred. All De-bonded Samples Were Examined Under A Stereomicroscope To Identify The Failure Mode.

Results: The Effect Of Type Of Surface Finish (sintered /one Surface Polished) Within The Specimens Showed That Sintered Provided Higher Bond Strength Than One Surface Polished . On Comparing Between The Type Of Surface Treatment Sandblasted Or Sandblasted + Hydrofluoric Acid Etched And Silanation Used In Each Subgroup, The Sandblasted Followed By Hydrofluoric Acid Etched And Silanation Provided Higher Bond Strength Than Sandblasted . Moreover, Calibra Resin Cement Provided Higher Bond Strength Than Panavia V5 Resin Cement.

Conclusions: It Was Concluded That The Type Of Surface Finish, Surface Treatment And Type Of Resin Cement Had A Significant Effect On The Shear Bond Strength Of Zirconia Reinforced Lithium Silicate Ceramics.