Evaluation of microleakage in Class II composite restorations: Bonded-base and bulk-fill techniques

Background: This study compared microleakage of Class II cavities restored using bonded-base and bulk-fill techniques with different bases. Materials Methods: In this in vitro study, 60 extracted human molars, standardized (4 mm × 2 8 mm) were prepared, such that the gingival floor was located 1 below CEJ. The teeth randomly divided into five groups filled with: (1) Fuji LC + x-tra fil, (2) Ionoseal (3) base (4) Grandio Flow (5) fil only [control group]; open-sandwich technique, thickness mm. bases coated all floor. Except for first group, where dentin conditioner used, Clearfil SE bond applied before application restorative materials as a bonding agent. After 500 thermocycles between 5°C 55°C, specimens immersed 0.5% basic fuchsine solution 24 h. sectioned, dye penetration observed by stereomicroscope at ×32. data analyzed Kruskal–Wallis Mann–Whitney tests SPSS software. significance determined 0.05 confidence interval. Results: statistical analysis revealed significant difference among (P Conclusion: use could reduce microleakage, including those composite restorations.