Sara A. Botros, Zainab M. Soliman, Dalia I. El-Korashy And Farid S. El-Askary .,
ABSTRACT
Aim: To Evaluate The Effect Of Pre-heating Temperatures Of A Dual-cured Adhesive And A Dual-cured Resin Composite As Well As Tubule Orientation On Micro-shear Bond Strength (�SBS) To Dentin. The Degree Of Conversion (DC%) Of The Adhesive And The Composite Was Also Evaluated At The Different Temperatures.
Materials and Methods: For �SBS, 90 Human Molars Were Randomly Divided Into 18 Groups (n=5) According To The Three Experimental Factors. Factor 1: Adhesive Temperature, Factor 2: Resin Composite Temperature; And Factor 3: Tubule Orientation (occlusal Or Axial). Adhesive And Composite Temperatures Were Set At 25�C, 32�C And 40�C. The Adhesive Was Applied To Dentin According To Manufacturer Instructions. Each Occlusal Dentin Was Stored With Four Composite Micro-cylinders, While Each Axial Dentin Was Stored With Two Micro-cylinders. The �SBS Testing Was Run At A Crosshead Speed Of 1mm/min. The DC% Of Adhesive And Composite Was Evaluated At Each Temperature Using FTIR. Data Were Analyzed By ANOVA/Tukey?s HSD Post-hoc Test (P=0.05).
Results: Three-Way ANOVA Revealed That Only ?tubule Orientation? And ?adhesive Temperature X Composite Temperature? Had A Significant Effect On �SBS (P=0.001 And P=0.002, Respectively). For Occlusal Surfaces, ?adhesive Temperature?, ?composite Temperature? And ?adhesive Temperature X Composite Temperature? Had No Significant Effect On �SBS (P>0.05). For Axial Surfaces, ?adhesive Temperature?, ?composite Temperature? Showed No Significant Effect On �SBS (P>0.05), While ?adhesive Temperature X Composite Temperature? Had A Significant Effect On �SBS (P=0.002). The Predominant Failure Mode Was The Mixed Type (57.43%). The Three Temperatures Tested Showed No Significant Effect On The DC% Of The Adhesive. On The Contrary, Pre-heating The Resin Composite To 40�C Revealed A Significant Higher DC% Compared To 25�C.
Conclusion: Tubular Orientation Seemed To Be An Influencing Factor On �SBS. Raising The Temperature To 40�C Improved The DC% Of Dual-cured Resin Composite, But Had No Effect On The Dual-cured Adhesive.
