The Effect of Satin Solution and Curing units on the hardness of Nanocomposite Resins

The aim of this study was to evaluate Vickers micro-hardness of two aesthetic light-cured nanocomposite resins (Filtek & Grandio). Specimens were prepared with a diameter of 10 mm and a thickness of 2 mm. from each resin composite and polymerized using plasma-arc light for 6s, light-emitting diode LED light for 40s and a conventional quartz-tungsten-halogen QTH light 40 s. Two beverages (coffee and tea) were used as staining solutions and distilled water (control). The measurements of surface hardness were done after 1,3 5,7,15, 30,and60 days by Vickers microhardness Vicker’s Hardness (VHN). Statistical analysis was preformed by two-way ANOVA (p<0.001) and the Tukey Multiple Comparison Test. It was found that surface hardness difference between water, tea and coffee for different periods; The lowest hardness data of the two types of composite were shown with plasma arc light, and these data were statistically different from the other two curing unit. While the highest hardness data were obtained in specimens cured with LED light curing units. The surface hardness of composite resins is time dependant, so it is significantly decreased with the increasing the time of immersion specially Grandio P