title: Assessment of the separation incidence of reciprocating WaveOne files: a prospective clinical study.
abstract: BACKGROUND
  Despite metallurgical advancements in the nickel-titanium file manufacturing process, file separation remains a concern. The purpose of this prospective clinical study was to assess the separation incidence of the reciprocating WaveOne file (Dentsply Tulsa Dental Specialties, Tulsa, OK) when used to prepare root canals of posterior teeth.
  
  
  METHODS
  File separation incidence was assessed over an 18-month period in which 4 experienced and calibrated endodontists performed conventional endodontic treatment on posterior teeth using the WaveOne file system. The separation incidence was determined based on both the number of teeth and the number of canals instrumented during this time period.
  
  
  RESULTS
  A total of 2,215 canals (711 teeth) were treated. Three instruments (two 21.06 and one 25.08) separated during use and were deemed to be irretrievable. The overall instrument separation incidence in relation to the number of canals shaped was found to be 0.13% (0.42% teeth).
  
  
  CONCLUSIONS
  Based on the results of this study, the incidence of endodontic instrument separation when using the WaveOne reciprocating file was considerably low.
authors.affiliation: Division of Endodontics, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address: rodrigo.cunha@umanitoba.ca.
authors.forename: Rodrigo Sanches
authors.initials: RS
authors.lastname: Cunha
authors.affiliation: Division of Endodontics, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Alanna
authors.initials: A
authors.lastname: Junaid
authors.affiliation: Graduate Program in Endodontics, Salta Endodontics Society, Salta, Argentina.
authors.forename: Pablo
authors.initials: P
authors.lastname: Ensinas
authors.affiliation: Private Practice Limited to Endodontics, Bloomingdale, Illinois.
authors.forename: William
authors.initials: W
authors.lastname: Nudera
authors.affiliation: Division of Endodontics at the CPO-Sao Leopoldo Mandic, Campinas, São Paulo, Brazil.
authors.forename: Carlos Eduardo da Silveira
authors.initials: CE
authors.lastname: Bueno
mesh_terms: D001641:Bicuspid / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D003722:Dental Alloys / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D004492:Edetic Acid / Q000627:therapeutic use; D055615:Electrical Equipment and Supplies; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009532:Nickel / Q000737:chemistry; D009811:Odontometry / Q000295:instrumentation; D011446:Prospective Studies; D011859:Radiography; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000706:statistics & numerical data; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D014025:Titanium / Q000737:chemistry; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging
chemical_list: D003722:Dental Alloys; D012388:Root Canal Irrigants; C040654:titanium nickelide; D009532:Nickel; D004492:Edetic Acid; D014025:Titanium; D012973:Sodium Hypochlorite
keywords: File fracture; WaveOne; nickel-titanium reciprocating instrument; separation incidence; separation of files