title: Wear of the Primary WaveOne single file when shaping vestibular root canals of first maxillary molar.
abstract: BACKGROUND
  It is very important for a clinician to know the increased wear of mechanized files when establishing endodontic therapy. The aim of this study was to check the wear of the Primary WaveOne file upon shaping two, four and six maxillary molar vestibular canals.
  
  
  METHODS
  The deterioration of 40 files, divided into four groups, was evaluated microscopically: group 1, control (unused); group 2, two canals; group 3, four canals; and group 4, six canals. After instrumentation, the files were embedded in resin and sectioned at their apical third into three equal parts. To analyze the wear of edges in the different sections, AutoCAD software was used and analysis of variance (ANOVA) was then performed to compare the mean rake angles.
  
  
  RESULTS
  The files with two and four uses showed slight wear, whereas those with six applications showed significant wear (p<0.05).
  
  
  CONCLUSIONS
  Primary WaveOne files can be used in up to four root canals without their edges losing effectiveness.Key words:Files wear, reciprocating motion, shaping capacity, WaveOne.
authors.affiliation: MSc, Dental School, Universidad Mayor, Temuco, Chile.
authors.forename: Daniel
authors.initials: D
authors.lastname: Aracena
authors.affiliation: PhD, Research Centre in Dental Sciences (CICO), Dental School, Universidad de La Frontera, Temuco, Chile.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Borie
authors.affiliation: MSc, Universidad de La Frontera, Temuco, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Betancourt
authors.affiliation: Prof, Universidad Autónoma de Chile, Chile.
authors.forename: Angella
authors.initials: A
authors.lastname: Aracena
authors.affiliation: PhD, Mechanical Engineering Department, Universidad de La Frontera, Temuco, Chile.
authors.forename: Mario
authors.initials: M
authors.lastname: Guzmán