Comparison of final irrigation techniques in removal of calcium hydroxide

The aim of this study was to compare new irrigation systems with a conventional irrigation technique for the removal of inter‐appointment calcium hydroxide [Ca(OH) 2 ]. Forty‐seven extracted human single‐rooted teeth were instrumented, and Ca(OH) 2 paste was placed into root canals by using a lentulo spiral at the apical third. Teeth were randomly divided into three groups according to different irrigation protocols using a 30‐gauge slot‐tipped needle, EndoVac system and ProUltra® PiezoFlow™ ultrasonic irrigation system. Scanning electron microscopic images of the selected root canal surfaces (cervical, middle and apical third) were evaluated using a 5‐grade scale. The influence of the irrigation system was evaluated using a two‐way analysis of variance test and Tukey's test. The EndoVac and PiezoFlow groups demonstrated the lowest scale values (cleanest canals); however, there was no statistical difference between these two groups. The conventional irrigation group exhibited significantly higher scores ( P  < 0.05). The conventional needle irrigation was not sufficient to remove Ca(OH) 2 from the root canal system. Irrigation with EndoVac and PiezoFlow™ ultrasonic irrigation systems improved the removal of the intracanal medicament resulting in cleaner root canal walls.