title: Efficacy of 2 reciprocating systems compared with a rotary retreatment system for gutta-percha removal.
abstract: BACKGROUND
  The maximum removal of root canal filling material is essential for successful endodontic retreatment. The purpose of this study was to assess the efficacy of 2 reciprocating systems (Reciproc [VDW, Munich, Germany] and WaveOne [Dentsply Maillefer, Ballaigues, Switzerland]) compared with a nickel-titanium (NiTi) rotary system (ProTaper Universal Retreatment [Dentsply Maillefer]) in the removal of root canal filling material.
  
  
  METHODS
  Sixty root canals of extracted human maxillary incisors were prepared using the NiTi ProTaper rotary system with the complementary use of a #40 K-type file and then obturated. The specimens were divided into 3 groups (n = 20) according to the system used for filling removal: group 1: instrument R25 of the Reciproc system, group 2: primary instrument of the WaveOne system, and group 3: NiTi rotary instruments of the ProTaper Universal Retreatment system. The teeth were cleaved longitudinally and photographed under a dental operating microscope with 5 × magnification. Images were transferred to a computer, and residual filling material was quantified using Image Tool software (University of Texas Health Science Center, San Antonio, TX). Results were compared using 1-way analysis of variance (P < .05).
  
  
  RESULTS
  All teeth examined had filling remnants within the canal. No statistically significant difference (P > .05) in residual filling material was observed among the groups, with 4.30% in group 1, 2.98% in group 2, and 3.14% in group 3.
  
  
  CONCLUSIONS
  The Reciproc and WaveOne reciprocating systems were as effective as the ProTaper Universal retreatment system for gutta-percha and sealer removal.
authors.affiliation: Department of Endodontics, Dental Research Center, São Leopoldo Mandic University, Campinas, São Paulo, Brazil.
authors.forename: Marcos de Azevêdo
authors.initials: Mde A
authors.lastname: Rios
authors.affiliation: Department of Endodontics, Sete Lagoas Dental Research Center, Salvador, Bahia, Brazil.
authors.forename: Alexandre Mascarenhas
authors.initials: AM
authors.lastname: Villela
authors.affiliation: Division of Endodontics, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Rodrigo Sanches
authors.initials: RS
authors.lastname: Cunha
authors.affiliation: Department of Endodontics, Dental Research Center, São Leopoldo Mandic University, Campinas, São Paulo, Brazil.
authors.forename: Rafael Cortez
authors.initials: RC
authors.lastname: Velasco
authors.affiliation: Department of Endodontics, Dental Research Center, São Leopoldo Mandic University, Campinas, São Paulo, Brazil.
authors.forename: Alexandre Sigrist
authors.initials: AS
authors.lastname: De Martin
authors.affiliation: Department of Endodontics, Dental Research Center, São Leopoldo Mandic University, Campinas, São Paulo, Brazil.
authors.forename: Augusto Shoji
authors.initials: AS
authors.lastname: Kato
authors.affiliation: Department of Endodontics, Dental Research Center, São Leopoldo Mandic University, Campinas, São Paulo, Brazil. Electronic address: carlosesbueno@terra.com.br.
authors.forename: Carlos Eduardo da Silveira
authors.initials: CE
authors.lastname: Bueno
mesh_terms: D003722:Dental Alloys / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D004867:Equipment Design; D006171:Gutta-Percha / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry; D010781:Photography / Q000379:methods; D011897:Random Allocation; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012389:Root Canal Obturation / Q000295:instrumentation; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D003722:Dental Alloys; D012387:Root Canal Filling Materials; C040654:titanium nickelide; D009532:Nickel; D006171:Gutta-Percha; D014025:Titanium
keywords: Gutta-percha; nickel-titanium files; reciprocating motion; root canal retreatment