Ragy Mohamed Elbadry, Sayed Hussein Saniour, Taheya Ahmed Moussa, Magdy W. Sabaa And,

ABSTRACT


Purpose: Evaluation Of The Bond Strength Of Resin Composite And Glass Ionomer Restorations To Gamma Radiated Enamel And Dentin Using A Desensitizing Agent And Different Adhesive Protocols.

Materials and Methods: Ninety Enamel And Dentin Samples (45 Each) Obtained From 15 Human Molars Were Divided Into 3 Main Groups (n=15): Control, Radiated, And Radiated/desensitized With Casein Phosphopeptide-amorphous Calcium Phosphate (CPP-ACP). The Samples Were Restored By Resin Composite (RC) Using Etch-rinse Or Self-etch Adhesives And Glass Ionomer (GI-self-adhesive) Then Sectioned To Obtain Beam-shaped Specimens. Micro-tensile Bond Strength (�-TBS) Was Measured And The Mode Of Failure Was Examined. Data Were Statistically Analyzed.

Results: Gamma Radiated Enamel/RC Showed Lower �-TBS Than The Control Group While Gamma Radiated/desensitized Enamel Restored With RC Showed The Lowest �-TBS Regardless To The Adhesives Used. Whereas, Gamma Radiated/desensitized Enamel/GI Showed The Highest Significant �-TBS Values Among The Enamel/GI Group. On The Contrary, The �-TBS Values Of Gamma Radiated Dentin/RC Using Either Adhesives Or Restored With GI Was Insignificantly Different Than Its Corresponding Control Groups. Nevertheless, Gamma Radiated/desensitized Dentin/GI Revealed The Highest �-TBS. Groups With The Low �-TBS Values Exhibited Predominantly Adhesive Or Mixed Failure Modes, While Predominance Of Cohesive And Mixed Failures Was Detected For Groups With The Higher �-TBS Values. Conclusion: Gamma Radiation Has A Detrimental Effect On The Enamel/RC Bond Strength Regardless The Adhesive Protocol Used. The CPP-ACP Has A Negative Effect On Both Enamel And Dentin Bonding To RC When Etch-rinse Or Self-etch Adhesive Protocol Were Used But Enhances That Of The Enamel/GI And Dentin/GI.