Nader M. Tadros, Mohammed N. Anwar And Farid S. El-Askary,

ABSTRACT

Objectives: This Study Was Conducted To Evaluate The Effect Of Different Thicknesses Of Chair-side Resin Composite Inlay Material On Shear Bond Strength And Nano-leakage Of Chemically-cured Adhesive/dual-cured Resin Cement. Methods: For Shear Bond Strength Testing, 100 Bovine Permanent Anterior Teeth Were Used In This Study. Subsequent To Teeth Grinding And Formation Of Smear Layer. The Teeth Were Randomly Divided Into Four Experimental Groups (n= 25 Teeth/group). For Group 1, 2 And 3, The Resin Cement Was Light Cured Through 2 Mm, 4 Mm And 6 Mm Thick Resin Composite Cylinder Respectively. While Group 4, The Resin Cement Was Left To Cure Chemically With The Self-etching Adhesive (Co-cure). On Ground Dentin Surfaces, 100 Pre-cured Resin Composite Cylinders With Thicknesses Mentioned Above Were Cemented Using Chemically-cured Adhesive/dual-cured Resin Cement According To Manufacturers? Instructions. Specimens Were Stored In 100% Relative Humidity For 48 Hours. SBS Test Was Run At A Crosshead Speed Of 0.5 Mm/min Using A Universal Testing Machine. For Nano-leakage Testing, 12 Resin Composite Discs Bonded To 12 Bovine Teeth Were Assigned Into 4 Groups (n = 3) As For SBS Testing. Specimens Were Evaluated Using SEM Operated In The Backscattered Mode To Detect Dye Penetration. Statistical Analysis Was Performed Using One-Way ANOVA/ Turkey?s HSD Post Hoc Test.

Results: The Results Showed That The Co-cure Group Exhibited The Significant Lowest SBS Values Among All Tested Groups. The 2 Mm Thickness Revealed The Significant Lowest Nano-leakage Score (0%) Among All Tested Groups.

Conclusions: Light Curing Of The Dual Cured Resin Cement Was Crucial To Achieve High SBS Values. There Was A Positive Direct Correlation Between The Thickness Of The Resin Composite Material And The Degree Of Nano-leakage.