Evaluation of internal adaptation of flowable and bulk-fill resin-based composites

This study aimed to evaluate and compare the internal adaptation of bulk-fill resin-based composite restorative materials with flowable composites as lining using self-etch adhesive system. Class I cavities (2mmx4mm) were prepared on flattened occlusal surfaces fifty extracted human premolars randomly assigned into five groups (n=10) according used: Beautifil Bulk-fill Restorative (BR); Flowable (BF); Flow F10 (BF10); Self-etch (SEA). Group A: SEA+BR; B: SEA+BF10+BR; C: SEA+BF+BR; D: SEA+BF10+SEA+BR E: SEA+BF+SEA+BR. The samples thermocycled for 500 cycles, then sectioned mesiodistally, polished pre-treated prior scanning electron microscopy (SEM) evaluation. From SEM images, measurement cohesive failures was recorded at multiple sites pulpal floor in between materials. Data analysed one-way ANOVA post-hoc Tukey tests (p<0.05). Cohesive failure SEA observed lowest percentage A (5.14%), highest C E (>16%). However, there no significant difference among all groups. Adhesive seen SEA+BF/BF10/BR SEA+dentine gaps formed (6.62%) SEA+BR (5.30%). Nonetheless, differences p=0.89 p=0.70, respectively. With use BF/BF10 floor, reduced but resulted increased failure. both absent (BF/BF10 BR) regardless or without application SEA.