RESUMO
OBJECTIVES: The aim of this study was to evaluate, in vitro, the ability of an 8% EDTA solution to remove debris and smear produced during root canal preparation. STUDY DESIGN: Single-rooted human teeth were used for this experiment. All root canals were instrumented in a similar fashion and irrigated with a 3.5% NaOCl solution. The teeth were divided into 6 groups. According to the groups, various final flushes were performed with a 15% or 8% EDTA solution for 1 or 3 min and with or without saline rinsing. After preparation, roots were separated into 3 thirds and each third was observed by SEM. Debris (D) and root canal smear (S) was evaluated twice. RESULTS: The results were subjected to ANOVA. The D and S scores for all test groups were statistically different from the control group without EDTA flush (P = .0001). The lowest D and S scores were obtained by a 3 min rinse with 8% EDTA solution and a statistical difference was observed in the apical third (P < .05). CONCLUSION: Under these in vitro conditions, 3 min 8% EDTA irrigation is as effective as 1 min 15% EDTA irrigation.