Effectiveness of Different Irrigation Systems and Irrigants on Smear Layer Removal Using SEM: An in Vitro Study

Objectives: The purpose of this study is to evaluate the effectiveness of the different irrigation systems and irrigants on the removal of the smear layer after instrumentation. Methods: Ninety freshly extracted, single-rooted mandibular premolars prepared using NI-TI rotary files and subjected to different irrigation regimens Group 1: Endo Vac with NaOCl. Group 2: NaoCl/EDTA. Group 3: NaoCl/Citric acid Group. 4: Endo Activator with NaOCl Group 5: Endo Activator with NaOCl/EDTA Group 6: Endo Activator with NaOCl/Citric acid Group 7: 27 Gauge closed-end needle with NaOCl Group 8: 27 Gauge closed-end needle with NaOCl/EDTA Group 9: 27 Gauge closed-end needle with NaOCl/Citric acid. The roots were split longitudinally, and then SEM images were taken to evaluate the amount of residual SR. Results: There is no statistically significant difference present between the cleaning efficiency of Endovac and Endoactivator in the coronal and middle location but statistically significant difference present in the apical region (p<0.05). There is a statistically significant difference present in various irrigant solutions. (p<0.05) NaOCl+EDTA, and NaOCl+citric acid irrigation sequence groups showed better smear layer removal when compared to NaOCl alone. Conclusion: None of the irrigation systems or solutions eradicate the smear layer. Endovac performed better in the apical third when compared to Endoactivator and needle irrigation regarding the smear layer removal. Among the irrigation solutions, NaOCl alone has the least smear layer removal efficacy when compared to and NaOCl+Citric acid, NaOCl+EDTA irrigation sequence groups.