Comparison of Three Final Irrigation Activation Techniques: Effects on Canal Cleanness, Smear Layer Removal, and Dentinal Tubule Penetration of Two Root Canal Sealers

Abstract

Objective: The aim of this study was to compare three final irrigation activation techniques with respect to their effects on debridement efficacy, smear layer removal, and dentinal tubule penetration of two different root canal sealers. Background data: Different applications to improve the delivery of irrigating solutions within the root canal system are currently being investigated, as not all of the mechanisms and effects of these techniques have been clearly identified. Materials and methods: One hundred forty-two single-rooted teeth were randomly divided into a control group and three experimental groups based on the irrigant activation technique used: EndoVac (EV) system, photon-induced photoacoustic streaming (PIPS), and conventional syringe irrigation (CSI). Thirteen specimens from each experimental group were evaluated for debris and smear layer removal using scanning electron microscopy. The remaining 30 specimens per group were divided into two subgroups according to the root canal sealer used: AH Plus and TotalFill BC. The maximum depth and total percentage of sealer penetration were measured using confocal laser scanning microscopy. Results: PIPS resulted in significantly less debris in the middle third of the root canal compared with CSI (p<0.01). There were no significant differences among CSI, EV, and PIPS concerning debris removal at coronal and apical levels or smear layer removal at all levels (p>0.05). TotalFill BC use after final irrigation with EV and CSI at 2mm or PIPS at 5mm exhibited a significantly higher percentage of sealer penetration than that with AH Plus (p<0.05). When AH Plus was used, PIPS allowed deeper sealer penetration than CSI at 2mm (p<0.05). Conclusions: The effects of EV, PIPS, and CSI on debridement efficacy, smear layer removal, and dentinal tubule penetration were almost comparable. TotalFill BC showed superior tubular penetration than AH Plus.