Evaluation of the efficiency of different irrigation systems used in root canal treathment on smear layer

Aim: The aim of this study is to investigate the effect of three different irrigation technics on smear layer occured during root canal preparation of maxillary incisors that has endodontic treatment indications.Materials and Method: Freshly extracted 60 maxillary incisors because of periodontal problems were used in this study. In preferring teeth such criterias as; nearly similar root lengths, no inclination of roorts and the same pulpal width were used. Debridement on roots were removed with a cretuar after extraction. Root surfaces were cleaned with brushes. Teeth were protected at room temperature in distilled water until usage day in study. Teeth were sectioned vertically to long axis 2 mm over enamel cement junction. Teeth were randomly divided into three groups of each 20. Coronal access of teeth were extended by the help of Gates Glidden to No V. Root canal preparation was started by using endodontic device and Protaper rotary instruments. Firstly root canal lengths were measured by K type root canal insturment and working lengths were determined as 1 mm shorter than foramen apicale. Extending operation was first started with SX among rotary instruments and then continued respectively as S1,S2,F1,F2 and resulted with F3. Different irrigation technics were used for each group. In group 1 irrigation was done with ultrasonic device. Irrigation was done at a regulated frequency for endodontic operation and by using specially prepared E4 and E11 instruments. First tank was filled with 5.25% NaOCl and second tank was filled with 17% EDTA as irrigation solution. When between each instrument changes 5.25% NaOCl was used, distilled water was used for final irrigation. In second group irrigation was done with classical method. After using SX instrument, irrigation was done by 27-gauge plastic syringe with 5.25% NaOCl. Irrigation was repeated after every instrument and finally was done with distilled water. In third group irrigation was done by Endo-Vac device. After every rotary instrument irrigation was done by MDT (master delivery tip) and macro canula with 5.25% NaOCl. And then was done by micro canula with 17%EDTA and 5.25 NaOCl. Distilled water was used for final irrigation. After irrigations root canals were dried with paper points. After preparation teeth were bucco-lingually and longitudinally sectioned by opening thin tunnels (hollows) burs by aerator device. Coronal, middle and apical parts of roots were analyzed under SEM . Obtained data was assessed with one way Kruskal-Wallis variance analysis (p<0.05).Results: Among Group 1 (Ultrasonic), Group 2 (Classic) and Group 3 (Endo-Vac) in terms of capacity of cleaning root surfaces statistically a significance was determined. That means presence of smear layer in three groups and in terms of whether dentine tubules are open and not; on coronal, middle and apical regions af root surface variability was determined.Conclusion: When capacity of cleaning of root canal surfaces of teeth were investigated; in coronal region irrigation by ultrasonic system, in middle region irrigation by classical syringe method and in apical region irrigation by Endo-Vac device determined successful.Key Words: Ultrasonic irrigation, Endo-Vac, Smear layer, NaOCl, EDTA, SEM