The effectiveness of using sonic and manual dynamic irrigation techniques to remove the smear layer on the apical third of a root canal wall

A smear layer can inhibit root canal sterilization and adaptation of root canal filling material on the apical third of a root canal wall. To eliminate this problemt, proper irrigation materials and techniques are needed. This study aimed to obtain more information about cleaning the smear layer on the apical third of a root canal wall that is irrigated using sonic and manual dynamic irrigation techniques. Thirty-two whole-extracted mandibular second premolars were divided into two groups. The teeth in Group 1 were irrigated using manual dynamic techniques, while the teeth in Group 2 were irrigated using sonic techniques. A scanning electron microscope (SEM) was used to inspect the cleanliness of the smear layer in the teeth in both groups. Then, a scoring method was used to determine the percentage of examination area in which the smear layer had been removed. The Kolmogorov-Smirnov test was used to analyze the data. There was no significant difference between Group 1 and Group 2 (p = 0.56); thus, no statistically significant difference was observed between both types of irrigation techniques. However, the sonic irrigation technique was better at cleaning the smear layer on the apical third of a root canal wall than the manual dynamic irrigation technique.