Effect of different final irrigating solutions on smear layer removal in apical third of root canal: A scanning electron microscope study

AIM: The aim of this in vitro study is to compare the smear layer removal efficacy of different irrigating solutions at the apical third of the root canal. MATERIALS AND METHODS: Forty human single-rooted mandibular premolar teeth were taken and decoronated to standardize the canal length to 14 mm. They were prepared by ProTaper rotary system to an apical preparation of file size F3. Prepared teeth were randomly divided into four groups (n = 10); saline (Group 1; negative control), ethylenediaminetetraacetic acid (Group 2), BioPure MTAD (Group 3), and QMix 2 in 1 (Group 4). After final irrigation with tested irrigants, the teeth were split into two halves longitudinally and observed under a scanning electron microscope (SEM) for the removal of smear layer. The SEM images were then analyzed for the amount of smear layer present using a three score system. STATISTICAL ANALYSIS: Data are analyzed using the Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: Intergroup comparison of groups showed statistically significant difference in the smear layer removal efficacy of irrigants tested. QMix 2 in 1 is most effective in removal of smear layer when compared to other tested irrigants. CONCLUSION: QMix 2 in 1 is the most effective final irrigating solution for smear layer removal.