RESUMO
Sixty teeth were used and divided into three equal groups. All root canals were prepared using the step-back technique and 5.25% NaOCl as an irrigation. For the first group, the roots received their final irrigation with 20 ml of EDTA followed by 10 ml of NaOCl then with 10 ml distilled water. The same technique was used for the final irrigation of the roots of the second group except that 50% citric acid was the chelating agent used. The third group was left as control. Each group was subdivided into two subgroups, roots of the first subgroups were filled with gutta percha using Grossman's root canal sealer, while those of the second subgroup were filled with gutta percha using composite bonding agent as a root canal sealer. The degree of leakage was assessed by the linear dye penetration method. From the results obtained, the sealing ability of the composite bonding agent was not relatively higher than that of Grossman's sealer, but the use of the smear layer removal agents improve significantly the sealing efficiency of the two sealing materials used in this study