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

Abstract

Objective: To evaluate the effect of lentulospiral and ultrasonic activation on the intra-tubular AH plus sealer penetration using confocal laser scanning microscopy. Materials and Methods: Twenty extracted single-rooted teeth were collected; teeth were prepared up to ProTaper finishing file F4 (size 40). Teeth were randomly divided into two main groups (n=10 teeth) according to activation techniques. The AH plus sealer with rhodamine B was activated by lentulospiral in group 1 and Irrisafe ultrasonic tip in group 2. The root canals were obturated with a single gutta-percha cone (size F4). The roots were sectioned at 3, 6, and 9 mm levels from the apex and examined with confocal laser scanning microscopy. Statistical analyses were performed at a 5% significance level. Results: At the cervical third, the lentulospiral 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 μm 2 ) of sealer penetration (P<0.05), while the Irrisafe group had significantly higher means of 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 > 0.01 and confidence of 99 %). Conclusions: Regarding sealer activation, lentulospiral performed better in the cervical region while activated Irrisafe ultrasonic tip performed better in the apical region.