'Efficiency of removal of debris from root canal system with help of different irrigation system:' An in vitro scanning electron microscope study

Aims and Objectives: The aim of this study was to determine the efficiency of EndoActivator, passive ultrasonic irrigation, side-vented needle, and syringe irrigation for removal of dentinal debris (smear layer) in root canals prepared with same master apical file sizes. Materials and Methods: Forty mandibular premolars with mature apices (extracted) were selected for this study. Each tooth was decoronated 2mm coronal to the cementoenamel junction with a diamond disk to facilitate straight-line access for instrumentation. Apical patency was determined by inserting an ISO # 08 K-file. Working length was determined by placing a size 15 K-file into the canal until it appeared at the apical foramen; this length was measured and the working length was set at 1mm short of this measurement. The roots were sealed with yellow sticky wax (DPI) to avoid apical extrusion during irrigation. The root canals were prepared to size 40, 0.02 taper, using step-back technique. After each instrument change, manual irrigation was performed with 2-mL NaOCl (3%) using a 26-gauge syringe. Then, a total of 40 samples were randomly distributed into four groups. According to group, root canals were irrigated with EndoActivator, passive ultrasonic irrigation, side-vented needle, and syringe irrigation. The roots were spilt and sent laboratory for examination under scanning electron microscope. Results: Ultrasonic irrigation had highest removal of the smear layer than the other irrigation systems followed by EndoActivator, side-vented needle, and syringe irrigation. Conclusion: Ultrasonic irrigation resulted in better removal of the smear layer in the apical third of root canals than EndoActivator, side-vented needle, and conventional needle irrigation.