RESUMO
AIM: To explore the microleakage of different adhesive systems and flowable composites to permanent teeth. SUBJECTS AND METHODS: In this study, a total of 84 human premolar teeth were used. Class V cavities were prepared on the buccal surfaces. The teeth were randomly assigned to six groups of 14 teeth each as follows: The first group - etch-rinse adhesive applied and cavities filled with flowable composite, the second group - etch-rinse adhesive applied and cavities filled with bulk-fill resin composite, the third group - one-stage self-etch (SE) adhesive applied and cavities filled with flowable composite, the fourth group - one-stage SE adhesive applied and cavities filled with bulk-fill resin composite, the fifth group - two-stage SE adhesive applied and cavities filled with flowable composite, and the sixth group - two-stage SE adhesive applied and cavities filled with bulk-fill resin composite. All specimens were then stored for 24 h at 37°C in distilled water. Teeth were then thermocycled for 500 cycles between 5°C and 55°C prior to immersion in 0.5% basic fuchsin for 24 h. Two mesiodistal cuts of each tooth were photographed for leakage with a digital camera. The dye infiltrated surface for each specimen was measured and data were collected with a software program. Statistical evaluations were done by nonparametric Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: There were statistically significant differences in mean microleakage ratio among the groups (P < 0.05). The first group had shown significantly increased microleakage areas than the other four groups (third, fourth, fifth, and sixth groups) (P < 0.05), except for the second group (P > 0.05). It was also no significant different between the mean microleakage areas of group fourth and group fifth (P > 0.05). The sixth group had exhibited the lowest microleakage areas, and it was statistically significant (P < 0.05) compared to the other groups. CONCLUSION: In this study, it has been found that the use of total etch adhesive systems resulted in high leakage values.