title: Reciprocating versus rotary systems for root filling removal: assessment of the apically extruded material.
abstract: BACKGROUND
  This study was designed to quantitatively evaluate the amount of apically extruded debris by comparing the ProTaper Universal Retreatment system (Dentsply Maillefer, Ballaigues, Switzerland) with 2 reciprocating single-file systems (Reciproc [VDW, Munich, Germany] and WaveOne [Dentsply Maillefer]) during endodontic retreatment.
  
  
  METHODS
  Forty-five mandibular premolars with a single canal were prepared with the ProTaper Universal system and then obturated. The specimens were divided into 3 groups (n = 15) according to the system used for filling removal: ProTaper Universal Retreatment system associated with the ProTaper Universal system (until file F4 40/0.06]), Reciproc system (Reciproc R40 [40/0.06]), and WaveOne system (WaveOne Large [40/0.08]). Sodium hypochlorite was used as an irrigant, and the apically extruded debris was collected in glass vials and then dried. The mean weight of debris was assessed with a microbalance and statistically analyzed using 1-way analysis of variance and post hoc Tukey multiple comparison tests (P < .05).
  
  
  RESULTS
  The ProTaper Universal Retreatment system produced significantly more debris compared with the Reciproc and WaveOne systems (P < .01). The reciprocating systems showed no significant difference between them (P > .05).
  
  
  CONCLUSIONS
  Under the conditions of the present study, all systems caused apical debris extrusion. Reciprocating systems were associated with less debris extrusion when compared with a conventional rotary retreatment system.
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: nogueiraemmanuel@hotmail.com.
authors.forename: Emmanuel João Nogueira Leal
authors.initials: EJ
authors.lastname: Silva
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Liliane
authors.initials: L
authors.lastname: Sá
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Felipe Gonçalves
authors.initials: FG
authors.lastname: Belladonna
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Aline A
authors.initials: AA
authors.lastname: Neves
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Thais
authors.initials: T
authors.lastname: Accorsi-Mendonça
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Victor T L
authors.initials: VT
authors.lastname: Vieira
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: De-Deus
authors.affiliation: Department of Endodontics, School of Dentistry - Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Edson J
authors.initials: EJ
authors.lastname: Moreira
mesh_terms: D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D011897:Random Allocation; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000737:chemistry; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation*; D012973:Sodium Hypochlorite / Q000737:chemistry; D019227:Tooth Apex / Q000473:pathology*; D019553:Tooth, Nonvital / Q000473:pathology*
chemical_list: D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite
keywords: Debris extrusion; nickel-titanium; reciprocating motion; root canal retreatment