To Comparison of Standard and New Chelating Solutions in Endodontics

Background: The use of 17% EDTA, followed by NaOCl irrigation during root canal instrumentation has been reported to effectively remove the smear layer from the root dentine walls. But EDTA is considered a pollutant and so it would be useful to identify alternative agents that offer greater biocompatibility. Materials and methods: The root canals of fifty single-rooted were randomly divided into five groups (n=10): 0.3% chitosan, 17% EDTA, 20% citric acid, 2.25% peracetic acid, and a control group (deionized water). The total volume of each chelating solution was collected and analyzed by FAAS for quantification of calcium ions. The roots were split longitudinally and examined by SEM for assessment of smear layer removal. Results underwent statistical analysis by one-way analysis of variance (ANOVA) and Tamhane's test. Results: 17% EDTA and 20% citric acid showed similar capacities for smear layer removal, with significant difference in comparison with 0.3% chitosan and the control groups; there were no significant differences between different parts of the roots. The highest calcium ion concentration was observed with 20% citric acid. Conclusion: 20% citric acid, 17% EDTA, 2.25% peracetic acid and 0.3% chitosan all removed the smear layer from the middle and apical thirds of root canals.