title: Comparison of ProTaper Next and HyFlex instruments on apical debris extrusion in curved canals.
abstract: OBJECTIVE
  To evaluate the amount of apically extruded debris after root canal instrumentation with ProTaper Next and HyFlex instruments in curved root canals.
  
  
  METHODS
  Forty extracted mandibular first molar teeth with curved mesial roots and of similar lengths were instrumented using ProTaper Next or HyFlex instruments. The extruded debris was collected into pre-weighed Eppendorf tubes. The tubes were stored in an incubator at 68 °C for 5 days. The tubes were weighed to obtain the final dry weight of the extruded debris. The weight of the extruded debris was determined by subtracting the initial weight from the final weight. Distribution of data was determined by Shapiro-Wilk test. Continuous variables were compared with the Independent Sample t-test or Mann-Whitney U-test. The significance level was set at P = 0.05.
  
  
  RESULTS
  Both instruments were associated with apical debris extrusion. The HyFlex group had significantly less debris extrusion than the ProTaper Next group (P = 0.014).
  
  
  CONCLUSIONS
  HyFlex CM was associated with significantly less apical extrusion than ProTaper Next.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: M M
authors.initials: MM
authors.lastname: Koçak
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey. ersancicek@beun.edu.tr.
authors.forename: E
authors.initials: E
authors.lastname: Çiçek
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Koçak
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: B C
authors.initials: BC
authors.lastname: Sağlam
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
authors.forename: F
authors.initials: F
authors.lastname: Furuncuoğlu
mesh_terms: D003762:Dental Instruments; D003786:Dental Pulp Cavity; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D018915:Root Canal Preparation / Q000295:instrumentation*; D019227:Tooth Apex / Q000473:pathology*
keywords: HyFlex CM; ProTaper Next; apical debris extrusion; curved canal