Confocal Laser Scanning Microscopy Evaluation of the Effect of Lentulo Spiral and Ultrasonic Activation on Intra-tubular Sealer Penetration

Objective: To evaluate the effect of lentulospiral and ultrasonic activation on the intra-tubular AH plus sealer penetrationusing confocal laser scanning microscopy.Materials and Methods: Twenty extracted single-rooted teeth werecollected; teeth were prepared up to ProTaper finishing file F4 (size 40). Teeth were randomly divided into two maingroups (n=10 teeth) according to activation techniques. The AH plus sealer with rhodamine B was activated bylentulospiral in group 1 and Irrisafe ultrasonic tip in group 2. The root canals were obturated with a single gutta-perchacone (size F4). The roots were sectioned at 3, 6, and 9 mm levels from the apex and examined with confocal laserscanning microscopy. Statistical analyses were performed at a 5% significance level. Results: At the cervical third, thelentulospiral group had significantly higher means of maximum depth (828.2±274.1 μm) and percentage (49.72±8.96%) and area (2774.9±908.6 μm2) of sealer penetration (P<0.05). While the Irrisafe group had significantly higher meansof maximum depth (486.9±269.9 μm) and percentage (24.34±13.21 %) sealer penetration at the apical third (P<0.05).There was a positive correlation between the maximum depth (μm) and the area (μm2) of sealer penetration (P < 0.01and confidence of 99 %). Conclusions: Regarding sealer activation, lentulospiral performed better in the cervical regionwhile activated Irrisafe ultrasonic tip performed better in the apical region.