Investigation of the effectiveness of chitosan, etidronic acid and edta in removing smear layer formed in root canal with two different activation methods

The aim of this study is to investigate the effectiveness of chitosan, etidronic acid and EDTA in removing the smear layer formed in the root canal with two different activation methods. In the study, 64 straight mandibular premolar teeth with single root and single canal structure were used. The teeth were decoronized to have a root length of 15 mm. They were randomly divided into 8 groups with 8 samples in each group. The root tip was covered with dental wax. Root canal preparation and 2,5% NaOCl irrigation were applied. The roots were embedded in eppendorf tubes containing silicone. In the final irrigation, 0,2% chitosan, 18% etidronic acid, 17% EDTA and distilled water were applied with sonic activation and passive ultrasonic activation. The roots were divided into two and examined in SEM analysis. Images were taken from each selected half root samples and scored in terms of smear layer by two different observers, the agreement between them was evaluated and statistical analysis was performed. The mean score of distilled water (control) group was significantly higher than chitosan (p:0.001), etidronic acid (p:0.001) and EDTA (p:0.001) groups (p<0.05). The mean score of etidronic acid group was significantly higher than chitosan group (p:0.004; p<0.05). There was no significant difference between the other groups (p>0.05). There was no statistically significant difference between the activation methods in terms of mean scores (p:0.651; p>0.05). The mean score in the apical third was significantly higher than middle (p:0.001) and coronal (p:0.001) thirds (p<0.05). The mean score in the middle third was significantly higher than coronal third (p:0.019; p<0.05). Key words: Chitosan, Etidronic Acid, EDTA, Smear Layer, SEM