The single-cone obturation technique with iRoot SP demonstrated strong filling capacity in circular root canals; however, its sealing ability in oval root canals remains underexplored. This study aimed to evaluate the sealing performance of the single-cone obturation technique with iRoot SP in oval root canals, in comparison with warm vertical compaction obturation. A total of 129 single-rooted teeth with oval canals were prepared using rotary instruments and randomly divided into three groups (n = 43 per group): warm vertical compaction obturation with AH Plus (WVC + AH Plus), warm vertical compaction obturation with iRoot SP (WVC + iRoot SP), and single-cone obturation with iRoot SP (SC + iRoot SP). Treatment assignment were blinded to researchers. Sealing ability was evaluated based on void volume percentage using micro-computed tomography, sealer penetration depth and percentage of penetration area in dentinal tubules using confocal laser scanning microscopy, and apical dye leakage depth using transparent teeth. Statistical analyses were conducted using one-way analysis of variance and post hoc Tukey's test with a significance threshold of 5%. The SC + iRoot SP group exhibited lower void volumes in the middle and apical thirds of the root canal but higher viod volumes in the cervical third (P < 0.05). In both the WVC + iRoot SP and SC + iRoot SP groups, the maximum and mean penetration depths at 2 mm and 5 mm from the apex were greater, and the percentage of penetration area was higher, compared to the WVC + AH Plus group (P < 0.05). The SC + iRoot SP group also displayed the smallest apical dye penetration depth (P < 0.05). SC + iRoot SP demonstrated superior sealing performance in the middle and apical regions of oval root canals making it a suitable option for sealing these specific areas.
Zhang et al. (Sat,) studied this question.