Abstract
INTRODUCTION: Successful root canal obturation requires a fluid-tight seal to prevent reinfection and promote healing. The aim of this study was to compare dentinal tubule penetration, void formation, and push-out bond strength of three premixed injectable bioceramic sealers (BioRoot Flow, ZenSeal, and Bio-C Sealer) with those of the conventional epoxy resin-based sealer AH Plus. MATERIALS AND METHODS: Ninety-six extracted human mandibular premolars with straight single canals were decoronated to 14 mm root length and prepared using ProTaper Gold rotary files up to F3, followed by standardized irrigation. The teeth were randomly divided into four groups (n = 24 each): BioRoot Flow, ZenSeal, Bio-C Sealer, and AH Plus (control). All the canals were obturated using the single-cone technique with F3 gutta-percha cones. After two weeks of storage at 37 °C and 100% humidity, the specimens were sectioned. Dentinal tubule penetration (n = 8 per group) was evaluated using confocal laser scanning microscopy with rhodamine B-labelled sealers. The void area (n = 8 per group) was measured under a stereomicroscope using the ImageJ software. Push-out bond strength (n = 8 per group) was tested using a universal testing machine. The data were then analyzed (p < 0.05). RESULTS: BioRoot Flow showed significantly greater dentinal tubule penetration than the other sealers in the coronal, middle, and apical thirds (p < 0.001), followed by Bio-C, ZenSeal, and AH Plus (lowest). Void formation was significantly higher in AH Plus than in all bioceramic sealers (p < 0.001), with BioRoot Flow and Bio-C exhibiting the smallest number of voids. The push-out bond strength was the highest for AH Plus across all levels (p < 0.001), followed by BioRoot Flow, ZenSeal, and Bio-C. In all groups, penetration and bond strength decreased significantly from coronal to apical, while the void area showed the opposite trend. CONCLUSION: Premixed injectable bioceramic sealers, especially BioRoot Flow, provided superior dentinal tubule penetration and significantly reduced void formation compared to AH Plus, with clinically acceptable bond strength. These findings support BioRoot Flow as an effective alternative for improving sealing performance in root canal obturation.