Sevinç Aktemur Türker1, Emel Uzunoğlu2, Mehtap Hülya Aslan3. 1. Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey. Electronic address: sevincaktemur@hotmail.com. 2. Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. 3. Microbiology Laboratory, Erzurum Regional Training and Research Hospital, Erzurum, Turkey.
Abstract
INTRODUCTION: The aim of this in vitro study was to evaluate the amount of apically extruded bacteria associated with several root canal preparation systems. METHODS: Forty-four extracted human mandibular premolar root canals were contaminated with an Enterococcus faecalis suspension. After incubation at 37°C for 24 hours, the root canals were instrumented using the Twisted File (SybronEndo, Orange, CA), OneShape (Micro Mega, Besançon, France), and ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland). During instrumentation, apically extruded bacteria were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in brain-heart agar medium for 24 hours. The numbers of colony-forming units were determined. The data obtained were analyzed using Welch analysis of variance followed by post hoc Games-Howell tests. RESULTS: ProTaper Next extruded the highest amount of bacteria, whereas OneShape extruded the least compared with all the other instruments (P = .004). There was a significant difference between OneShape and ProTaper Next in the number of colony-forming units (P = .007) but not between OneShape and Twisted File (P > .05). CONCLUSIONS: All instrumentation systems extruded bacteria beyond the foramen. The OneShape system extruded less bacteria compared with the Twisted File and ProTaper Next systems.
INTRODUCTION: The aim of this in vitro study was to evaluate the amount of apically extruded bacteria associated with several root canal preparation systems. METHODS: Forty-four extracted human mandibular premolar root canals were contaminated with an Enterococcus faecalis suspension. After incubation at 37°C for 24 hours, the root canals were instrumented using the Twisted File (SybronEndo, Orange, CA), OneShape (Micro Mega, Besançon, France), and ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland). During instrumentation, apically extruded bacteria were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in brain-heart agar medium for 24 hours. The numbers of colony-forming units were determined. The data obtained were analyzed using Welch analysis of variance followed by post hoc Games-Howell tests. RESULTS: ProTaper Next extruded the highest amount of bacteria, whereas OneShape extruded the least compared with all the other instruments (P = .004). There was a significant difference between OneShape and ProTaper Next in the number of colony-forming units (P = .007) but not between OneShape and Twisted File (P > .05). CONCLUSIONS: All instrumentation systems extruded bacteria beyond the foramen. The OneShape system extruded less bacteria compared with the Twisted File and ProTaper Next systems.