Assessment of Apical Extrusion of Debris during Root Canal Preparation with Different Ni–Ti File Systems: An In Vitro Study

Abstract

The aim of this study was to evaluate the apical extrusion of debris during root canal preparation with the use of different Nickel-Titanium (Ni-Ti) file systems. Totally 60 single-rooted human mandibular premolar teeth with fully formed roots were chosen for the study. The coronal access cavity and all other preparations were done with the use of an access cavity kit and then 60 samples were randomly separated into three investigational groups (n = 20); group I: self-adjusting file, group II: WaveOne Gold, and group III: Mtwo rotary system. After instrumentation, the teeth were taken out from the tube and the root surface-adherent debris was collected by washing off the apical area of the tooth with distilled water (1 ml) into a centrifuge tube. The centrifuge tube was kept for 5 days in an incubator at 70°C to permit evaporation of the moisture prior to weighing the dry debris with the aid of an electrical analytical balance. The highest quantity of debris extruded was by the Mtwo rotary system (0.0394 ± 0.880) followed by WaveOne Gold (0.0247 ± 1.030) and self-adjusting file (0.0198 ± 0.102). A statistically significant difference (p < 0.001) was found between the various file systems. After considering the drawbacks of this study, apical debris extrusion could be found with all three groups. However, the self-adjusting file demonstrated a significantly reduced quantity of apical debris extrusion compared to the Mtwo rotary system and WaveOne Gold. The chief step during the procedure of root canal treatment is the preparation of the infected root canals biomechanically. This preparation may lead to forcing the apical debris into the periapical space through the apical foramen, resulting in host-initiated immunological response which leads to postoperative discomfort and pain. This consequently leads to selection of a specific rotary system for endodontic treatment.