Abstract:

Objective: This study aimed to evaluate and compare the microleakage of different bulk-fill restorative materials in Class II cavities of primary molars using high-resolution micro-computed tomography (micro-CT).
Materials and Methods: Fifty standardized mesio-occlusal and disto-occlusal Class II cavities were prepared and restored in extracted, intact primary molars using five restorative materials: SDR, Tetric EvoCeram Bulk-Fill, VisCalor Bulk, Cention N, and Dyract XP. All restorations were finished, polished, and subjected to thermocycling of 1000 cycles. Microleakage was assessed via silver nitrate dye penetration and quantified using micro-CT imaging. The microleakage was analyzed using one-way ANOVA with Tukey’s test applied for pairwise comparisons. The significance threshold was established at 5% (p = 0.05).
Results: All tested materials demonstrated similar microleakage patterns, with mean penetration ratios ranging from 0.569 to 0.673. No statistically significant differences were found among the five groups (p>0.05).
Conclusion: All tested bulk-fill materials exhibited comparable microleakage performance in primary molars. The results suggest that when proper adhesive protocols and techniques are followed, modern bulk-fill composites, including thermoviscous and alkasite materials, can provide effective marginal sealing in pediatric restorative procedures.

Keywords: Microleakage, Bulk-fill composites, Primary molars, Micro-CT, Cention N, VisCalor, SDR