Effect of maintaining apical patency and passive ultrasonic irrigation on irrigant penetration into the apical third of root canals: An in vivo study

Abstract

Introduction: The aim of this study was to determine whether the use of a patency file and passive ultrasonic irrigation (PUI) is related to the presence of a radiopaque irrigating solution in the apical third of human root canals in vivo. Materials and Methods: 20 human root canals were randomly divided into 4 groups. 1: Conventional needle irrigation without apical patency, 2: PUI without apical patency, 3: Conventional needle irrigation with apical patency, 4: PUI with apical patency. Apical patency was maintained with a no. 10 K-file 1mm beyond the working length. PUI was done using an endosonic file attached to the ultrasonic unit. The canals were shaped with the Pro Taper system. Irrigation was performed with solution prepared with a radiopaque contrast medium and sodium hypochlorite 5.25%. Digital images were taken and a calibrated reader determined the presence or absence of the irrigating solution in the apical third. Results: Significantly more canals with irrigant in the apical third were found after PUI and after maintain apical patency. Conclusion: PUI and maintaining apical patency improves irrigant penetration.