Microleakage assessment of one- and two-step self-etch adhesive systems with ‎the low shrinkage composites

BACKGROUND AND AIM: Different studies evaluating one-step self-etch (SE) adhesive systems show contradictory findings, so the aim of this study was to compare the microleakage of one-step SE adhesive systems and CLEARFIL SE BOND (that serves as the “gold-standard” SE adhesive) with low shrinkage composites. METHODS: In this in vitro study, Class V cavities with the occlusal margin in enamel and cervical margin in cementum were prepared on the buccal and lingual surfaces of 36 human premolars and molars (72 cavities). The enamel surfaces of the cavities were etched with 37% phosphoric acid and then the specimens were divided into six groups of 6 (12 cavities) and the cavities were restored according bellow: Group 1 (Kalore-GC + G-Bond), Group 2 (Grandio + Futurabond NR), Group 3 (Aelite LS Posterior + All Bond SE), Group 4 (Kalore-GC + CLEARFIL SE BOND), Group 5 (Grandio + CLEARFIL SE BOND), and Group 6 (Aelite LS Posterior + CLEARFIL SE BOND). All the specimens were thermocycled for 2000 cycles (5-55 °C) and then placed in 0.5% basic fuchsine dye for 24 hours at 37 °C and finally sectioned and observed under the stereomicroscope. Data were analyzed using Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests at a P < 0.050 level of significance. RESULTS: In comparison between occlusal and gingival margins in each group, microleakage in occlusal margins was significantly less than the gingival margins (except Kalore + CLEARFIL SE BOND) (P > 0.050). There were no significant differences in microleakage among two-step and one-step SE adhesive systems on both the occlusal and gingival margins. CONCLUSION: According to this study, two-step SE adhesive system (CLEARFIL SE BOND) did not provide better marginal seal than the one-step SE adhesive systems.