Evaluating the effect of different irrigation activation techniques on the dentin tubules penetration of two different root canal sealers by laser scanning confocal microscopy

Abstract

Purpose: The aim of this study is to evaluate the effect of different irrigation activation techniques on the dentin tubules penetration of two different sealers by confocal laser scanning microscope (CLSM).

Methods: A hundred premolar teeth were used in this study. The root canals were shaped and irrigated with 5% NaOCl and 17% EDTA using the following final irrigation activation techniques in each group; Group1: Conventional Syringe Irrigation (CSI), Group2: Passive Ultrasonic Irrigation (PUI), Group3: Apical Negative Pressure (EndoVac), Group4: Er:YAG laser and Group5: Er,Cr:YSGG laser. Then the teeth were separated two subgroups according to sealers (AH-Plus and Totalfill-BC). Horizontal sections were obtained at 2, 5, 8 mm distance of apex. Images were obtained with CLSM and the penetration areas of sealers were calculated with four different dentin tubule penetration assessment techniques. The data were statistically analyzed with Kruskal Wallis and Mann Whitney U tests.

Results: No significant difference was observed between the sealers (p > .05). EndoVac, Er:YAG and Er,Cr:YSGG laser activation groups were observed to have a significantly higher mean penetration depth, penetration percentage and penetration area than the Control group. There was a significant difference between all regions in all penetration parameters (p < .05).

Conclusions: While the use of resin or bioceramic-based root canal sealers did not affect dentin tubule penetration, the use of activation techniques positively affect the dentin tubule penetration. The average tubule penetration and penetration area assessment techniques are suitable methods for the investigation of dentinal tubule penetration.

Research highlights: It can be stated that the use of resin or bioceramic based root canal sealers does not affect dentin tubule penetration and the use of irrigation activation techniques during removal of the smear layer positively affects dentinal tubule penetration. In addition, it has been determined that the average tubule penetration and penetration area assessment techniques are suitable methods for the investigation of dentinal tubule penetration.

Keywords: confocal microscopy; dentinal tubule penetration; irrigation activation; laser.