title: Apical transportation associated with ProTaper Universal F1, F2 and F3 instruments in curved canals prepared by undergraduate students.
abstract: OBJECTIVE
  This study evaluated apical transportation associated with ProTaper Universal Fl, F2 and F3 rotary files in curved canais prepared by undergraduate students.
  
  
  METHODS
  Twenty mesial roots of mandibular molars with curvatures ranging between 25° and 35° were selected. Mesiobuccal canals were instrumented by twenty students with the ProTaper system (Dentsply-Maillefer, Ballaigues, Switzerland) according to the manufacturer's instructions. Pre-fiaring was performed with Sl and SX files. A #15 K-file was inserted into the root canal up to the working length (WL), and an initial digital radiograph was taken in a buccolingual direction (baseline). Afterwards, the S1, S2, F1, F2, and F3 files were employed up to the WL. Other radiographies were taken in the same orientation of the baseline after the use of the Fl, F2, and F3 files, with each file inserted into the root canal. The radiographic images were overlapped, and the Image J software was used to measure the distance between the rotary files' ends and the #15 K-file's end, characterizing the apical transportation. Data were analyzed by Repeated Measure ANOVA and by the SNK post hoc test (P<0.05).
  
  
  RESULTS
  It was verified that file size affected apical transportation significantly (P<0.001). The F3 file showed higher apical transportation than Fl and F2, while between these last files there was no difference.
  
  
  CONCLUSIONS
  The undergraduate students produced lower apical transportation in curved canals when they did not use the F3 rotary file.
authors.affiliation: Interinstitutional PhD program, State University of Montes Claros, Montes Claros, MG, Brazil.
authors.forename: Manoel
authors.initials: M
authors.lastname: Brito-Júnior
authors.affiliation: Department of Dentistry, Federal University of Sergipe, Aracaju, SE, Brazil.
authors.forename: André Luis
authors.initials: AL
authors.lastname: Faria-E-Silva
authors.affiliation: Interinstitutional PhD program, State University of Montes Claros, Montes Claros, MG, Brazil.
authors.forename: Carla Cristina
authors.initials: CC
authors.lastname: Camilo
authors.affiliation: Department of Dentistry, United Universities of the North of Minas, Montes Claros, MG, Brazil.
authors.forename: Rodrigo Dantas
authors.initials: RD
authors.lastname: Pereira
authors.affiliation: Department of Restorative Dentistry, State University of Montes Claros, Montes Claros, MG, Brazil.
authors.forename: Neilor Mateus Antunes
authors.initials: NM
authors.lastname: Braga
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Manoel Damião
authors.initials: MD
authors.lastname: Sousa-Neto
mesh_terms: D000704:Analysis of Variance; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D009532:Nickel; D009811:Odontometry; D011859:Radiography; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D013335:Students, Dental; D014025:Titanium; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
chemical_list: C040654:titanium nickelide; D009532:Nickel; D014025:Titanium