COMPARISON OF THE MICROTENSILE BOND STRENGTH OF FOUR DIFFERENT BULK-FILL RESIN COMPOSITES OF CLASS I CAVITIES WITH DENTIN

Objectives: The aim of this study is to compare the microtensile bond strengthsof four different bulk-fill composites and a microhybrid composite to the dentin.Materials and methods: 4 bulk-fill composites and a microhybrid compositewere tested. Class I occlusal cavities were prepared on 25 freshly drawn intacthuman molar teeth, randomly divided into five groups [G-aenial posterior (Controlgroup), Estelite Bulk Fill flow, GrandioSO x-tra, Beautifil Bulk Restorative, FillUp] and the cavities were restorated with five composite systems by using theirown adhesive systems. Completed restoration teeth bukkolingual and mesiodistalsections were taken, three samples were obtained from each tooth. Microtensilebond strength values of groups were measured by universal test machine.Microscopic changes were examined by SEM. The data were evaluated by oneway ANOVA and Tukey tests.Results: While the control group showed the highest microtensile bond strength,Fill-Up group showed the lowest. The control group was statistically significantwhen compared to the four different bulk-fill groups used in the study (p<0.05).Although the GrandioSO x-tra group showed the highest bonding strength amongthe bulk-fill composites, the differences between the Beautifil Bulk Restorativeand Estelite Bulk Fill flow were statistically insignificant (p>0.05). Fill-Up wasfound to be statistically significant when compared to the other bulk-fill groups(p<0.05). In SEM analyzes a regular gap is seen along the hybrid layer only inEstelite Bulk Fill flow.Conclusions: No bulk-fill composite group could reach the value of the bondstrength of microhybrid composite. Although the Fill-Up group was used with theetch and rinse adhesive system among the bulk-fill composites, it showed thelowest bond strength.