Final Rinse Optimization: Influence of Different Agitation Protocols

Introduction: This study examined the effect of different root canal irrigant agitation protocols in the penetration of an endodontic irrigant into dentinal tubules. Methods: Fifty-six human single-rooted teeth were shaped with nickel-titanium instruments, and a final rinse of 5% sodium hypochlorite labeled with 0.2% alizarin red was performed. Specimens were assigned to 7 groups (N = 8) and submitted to the following rinse activation protocols: no agitation (control group), K-File or gutta-percha agitation, or different sonic (EndoActivator [Advanced Endodontics, Santa Barbara, CA] and Plastic Endo, Lincolnshire, IL) and ultrasonic (Satelec [Acteongroup, Merignac, France] and EMS, Nyon, Switzerland) agitations. Specimens were sectioned at 1, 3, and 5 mm from the apex in 1-mm-thick slabs, ground, and prepared for fluorescence microscopy at 100× with a wavelength of 450 milliseconds. Irrigant penetration into dentinal tubules was analyzed by using Kruskal-Wallis analysis of variance followed by post-hoc comparisons. Results: Groups were ranked in the following order: control = K-file = gutta-percha < EndoActivator = Plastic Endo < Satelec = EMS. At 1 mm from the apex, the highest score was found for the EMS group compared with the control, K-file, gutta-percha, EndoActivator, and Plastic Endo groups, whereas no difference was found with the Satelec group. Conclusion: The results support the use of an ultrasonic agitation to increase the effectiveness of the final rinse procedure in the apical third of the canal walls.