Comparison of smear layer removal using four final-rinse protocols

50 INTERNATIONAL DENTISTRY – AUSTRALASIAN EDITION VOL. 7, NO. 1 Abstract Objectives: This study aimed to compare the efficacy of Tetraclean and 17% EDTA as final irrigants in the removal of the smear layer in the coronal, middle and apical thirds of the instrumented root canal. Methods and Materials: Forty extracted human permanent teeth (n=10) were randomly assigned to 4 groups: no smear layer removal (group 1); EDTA rinse (group 2); liquid component of Tetraclean only (group 3); Tetraclean (group 4). The specimens were analyzed using scanning electron microscopy analysis at 500X and 1000X magnification and cleaning was evaluated at the apical, middle, and cervical levels using a threepoint scoring system. Data were statistically analyzed using Kruskal-Wallis analysis of variance test (5% significance level). Results: When the entire canal was considered, groups were ranked in the following order: 1>2≥3=4 (p<0.05). For different sections of the canal space, distance from the apex (2, 6 and 10 mm) influenced smear layer removal within each group (p<0.05). Discussion: Differences between EDTA and Tetraclean were only evident at 6 mm from the apex, whereas at 2 mm both protocols had similar performances in smear layer removal from the root canal system of single-rooted permanent teeth. Conclusions: the use of a chelating agent leads to a higher removal of smear layer from the root canal walls.