title: Comparison of apically extruded debris associated with several nickel-titanium systems after determining working length by apex locator.
abstract: OBJECTIVE
  To compare apically extruded debris using ProTaper Universal (PTU), ProTaper Next (PTN), WaveOne (WO), Twisted File (TF), M-Two (MT), and Revo-S (RS) after determining the working length (WL) with root ZX.
  
  
  METHODS
  Seventy-two teeth were selected. The WL determination was performed with root ZX. The teeth were divided into six experimental groups, randomly. In groups, root canals were prepared with PTU to size F4/0.06, with PTN to size X4/0.06, with WO to size 40/0.08, with TF to size 40/0.04, with MT to size 40/0.06, and with RS to size AS40/0.06. After preparations were completed, final irrigation was performed with 2 mL distilled water, and a total of 10 mL of distilled water was used in each tooth. Tubes were stored in an incubator at 68°C for 5 days to evaporate the distilled water before weighing the dry debris. Data were analyzed by the Mann-Whitney U-test.
  
  
  RESULTS
  The RS group led to the highest amount of extruded debris, however, WO led to the least amount of extruded debris. There was no statistically difference among the groups (P > 0.05).
  
  
  CONCLUSIONS
  The authors conclude that the results obtained might depend on the apex locator used to determine the WL.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Ersan
authors.initials: E
authors.lastname: Çiçek
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Oguzhan
authors.initials: O
authors.lastname: Akkocan
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Furuncuoglu
keywords: Apex locator; apical extrusion; instrumentation; nickel-titanium systems