Evaluation of smear layer removal using maleic acid with different irrigation techniques

The aim of this study was to evaluate the efficacy of NaviTip, NaviTip FX and EndoUltra in removal of smear layer from the instrumented root canal when used with 7% maleic acid (MA). Thirty extracted human maxillary anterior teeth were decoronated to standardize the root length to 15 mm. The canals were enlarged to size F5 using protaper files. 5 ml of 2.5% NaOCl was used as an irrigating agent between each instrument change. Samples were then divided into three groups (n=10) based on irrigation regimen. Group 1- EndoUltra group: 2.5 ml of 7% MA was irrigated for 30 sec. Then the root canals were irrigated with 5 ml of distilled water for 1 min following which, EndoUltra device was activated for 30 seconds within the canal. The same procedure was repeated once more, so that the total irrigation time with 7% MA and activation time with EndoUltra was 1 min. Group II: Navitip FX group: 5 ml of 7% MA was irrigated using 15 size Navitip FX needle for 1 min. Group III:Navitip group (control): 5 ml of 7% MA was irrigated using 30 gauge Navitip needle for 1 min. All the specimens were then subjected to SEM analysis. On intra-group comparison, NaviTipand NaviTip FX groups removed smear layer better in the coronal and middle third when compared to the apical third. However, in EndoUltra group, there was no significant difference between coronal, middle and apical thirds. On inter-group comparison, Navitip group removed smear layer less efficiently as compared to Navitip FX and EndoUltra groups in all the thirds of the root canal. When Navitip FX group was compared to EndoUlra group, there was no significant difference between them in coronal and middlethirds. However, in the apical third, EndoUltra group removed smear layer more effectively. EndoUltra removed smear layer more efficiently than NaviTip FX and NaviTip from the apical third of the root canal system when used along with 7% MA.