Evaluation Of Three Universal Adhesive s Effect On Micro Shear Bond Strength With Composite Resin To Dentin

Introduction: shelf life of adhesive bonds is an important factor in success of adhesive restorations. Micro-shear bond strength test is extensively used for assessment of bond strength. The aim of this study is assess the effect of shelf life of the different types of universal adhesives on the microshear bond strength of a resin composite to dentin. methods: In this experimental study, flat ground dentin surfaces were obtained on 48 extracted human premolars. The composite resin (Z100, 3M, ESPE) was placed over the specimens using different universal adhesives [Scotch bond universal (SBU); All bond universal (ABU); and Peak universal bond (PUB)] at different time intervals from their production time (24 hours, 6- and 12 months). And finally exposed to microshear stresses at a rate of 1 mm/min. The failure mode was assessed under stereo microscope (X40). The results were analyzed using Two-way ANOVA and Turkey’s HSD test (P<0.05). Results: In all groups, the microshear bond strength was significantly reduced as the time elapsed from the production time (P<0.05). The mean and standard deviation of microshear bond strength of different types of universal adhesive were as follow: SBU [24 h (56.84±4.32); 6- (44.60±3.17); and 12 months (28.46±2.88)]; ABU [24 h (38.69±2.33); 6- (29.74±2.43); and 12 months (11.32±1.21)]; and PUB [24 h (28.83±3.29); 6- (20.32±1.94); and 12 months (11.65±1.43)] MPa. In the most specimens, the failure mode was mixed; however, the numbers of adhesive failures was increased by time. Conclusion: The microshear bond strength of resin composite to dentin applying different universal adhesives was reduced as the time elapsed from their production time.

کلیدواژه ها:

Microshear ، Universal adhesive ، Shelf life