Effect of Different Agitation Techniques on the Penetration of Irrigant and Sealer into Dentinal Tubules.

Objective: The aim of this study was to compare the effectiveness of five intracanal agitation techniques on the penetration of irrigant and sealer into dentinal tubules. Background data: Intracanal agitation techniques could promote chemomechanical debridement and the sealing of root canals during endodontic treatment. However, there is limited evidence for the agitation effect of Nd: YAP laser. Materials and methods: Human maxillary premolars with single straight canals (N= 60) were prepared with ProTaper Next (R) NiTi rotary files (Dentsply Maillefer) up to X4 (ISO 40 size). Rhodamine B-labeled sodium hypochlorite was used for final irrigation together with the conventional syringe (control), sonic, ultrasonic, Nd: YAP laser, or V-Clean (TM) endodontic agitation system. All canals were obturated with gutta-percha and fluorescein isothiocyanate-labeled AH Plus sealer. Transverse sections were obtained at 2, 5, and 8mm from the apex and observed under confocal laser scanning microscopy. Maximum penetration depth and penetration percentage of both irrigant and sealer were recorded. Kruskal-Wallis and Mann-Whitney tests were performed for multiple comparisons. The Spearman coefficient was calculated to confirm correlations between irrigant and sealer penetration. Results: Laser agitation attained the most irrigant and sealer penetration depth and penetration percentage (p < 0.05). Sonic and ultrasonic agitation attained significantly more penetration percentage than the control group at 2mm from the apex (p < 0.05). Patterns of irrigant and sealer penetration correlated significantly for all agitation techniques (p < 0.001). Conclusions: Nd: YAP laser was superior to other agitation techniques in dentinal tubule penetration of irrigant and sealer at one or more sectioned levels from the apex.