Evaluation of the effects of different sonic irrigation activation techniques used in root canal treatment on dentinal tubule penetration of sealers with laser scanning confocal microscope

Introduction and Aim: Irrigation has an important place in root canal treatment in order to provide disinfection in the root canal system, since the area that can be reached with mechanical instrumentation is limited. Different techniques have been investigated in order to transport irrigation solutions to the root canal system more effectively, but the mechanisms and effects of these investigated techniques have not been fully explained yet. The aim of this study is to compare the effects of three different irrigation techniques on irrigation solution and two different sealers used in root canal filling on percentages and depths of penetration into dentinal tubules. Material and Method: 36 single rooted with a single canal mandibular premolar human teeth were randomly divided into three groups according to the used irrigation technique: conventional irrigation (CI) method, EDDY and EndoActivator groups. 12 samples are divided into 2 subgroups according to the sealer to be used in filling: AH Plus and TotalFill BC subgroups. After the root canal filling, 1 mm sections were taken at 2, 5 and 8 mm distances from the apex representing the apical, middle and coronal segments, respectively. Percentage of dentinal tubule penetration and maximum penetration depth of root canal sealers were measured using by a confocal laser scanning microscope (CLSM). Results: Penetration percentages of both irrigation solution and root canal sealers increased from apical to coronal. In the examination of irrigation solution penetration percentages, the ED group values at the apical third were significantly higher than the CI group (p <0.05). ED and EA groups both showed significantly higher results than CI at middle and coronal thirds (p <0.05). In the comparison of the penetration percentages of the root canal sealers used, no significant difference was found at the CI, ED and EA groups at the apical and coronal thirds in terms of penetration percentages of AH Plus and TotalFill BC sealers (p> 0.05). At middle thirds; In all groups, a significant difference was observed in terms of sealer penetration percentages, and in all groups, the penetration percentage of TotalFill BC was significantly higher from AH plus group (p <0.05). At the apical third, the ED group values in the penetration percentages of both AH Plus and TotalFill BC were found to be significantly higher than the other groups (p <0.05). In the penetration percentages at the middle third; In AH Plus and TotalFill BC subgroups; It was observed that the values of the ED and EA groups were significantly higher than the CI values (p <0.05). No significant difference was found between CI, ED and EA groups in AH Plus and TotalFill BC subgroups in percentages of penetration in coronal sections (p> 0.05). Conclusion: The findings of our study revealed that the use of irrigation activation techniques increases irrigation solutions and root canal sealer penetration into dentinal tubules.