Evaluation of smear layer removal of radicular Dentin in comparison with different irrigation devices: An in vitro study

Aim: The aim of this study was to evaluate the efficacy of smear layer removal from the root canals using 2 ml of 5.25% sodium hypochlorite passive ultrasonic irrigation, EndoVac, and diode laser during endodontic therapy. Materials and Methods: Forty single-rooted human teeth were selected. Access cavity preparation was done. Working length was determined. Instrumentation was initiated with ISO hand files number 15 k file, followed by ProTaper rotary files size F3. Two milliliters of 5.25% NaOCl was used as an irrigant after every instrumentation, with a final flush of 17% EDTA, followed by a rinse with 3 ml of distilled water. Teeth samples were divided into four groups – Group I (n = 10) conventional irrigation with 5.25% NaOCl, 17% EDTA for 1 min, Group II (n = 10) instrumented and irrigated with ultrasonic activation for 1 min, Group III (n = 10) instrumented and irrigated with EndoVac for 1 min, Group IV (n = 10) (analyzed with irradiation of 2 W continuous wave of 910 nm diode laser). Teeth samples were then sectioned longitudinally. Scanning electron microscope examination of canals was done for evaluating smear layer at different levels. Statistical data analysis was done by one-way ANOVA test to evaluate the smear layer score at a significance level of P ≤ 0.05. Results: Group III and Group IV have a minimal amount of smear layer at the apical third when compared to Group I and Group II which was statistically significant with a P < 0.05. Conclusion: Diode laser and EndoVac performed better in removing the smear layer when compared with 2 ml of 5.25% sodium hypochlorite and ultrasonic irrigation.