title: Evaluating Transportation by Comparing Several uses of Rotary Endodontic Files.
abstract: To evaluate the frequent use of ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland) systems on shaping ability of root canal utilizing Solidworks (2014, Dassault Systemes) software.
  
  
  
  Thirty-six root canals in clear resin blocks (Dentsply-Maillefer) were allocated into six experimental groups (n = 36). Six new sets of PTN instruments (Dentsply Maillefer, Ballaigues, Switzerland) were used six times to shape the resin blocks. A #15 K-file was inserted to the working length (WL), followed by ProGlider (PG) to create a glide path. Sequential use of PTN instrumentation in a crown-down technique was used to reach size (30/07) apically. Macroscopic photos of the blocks were taken before and after instrumentation, layered by Paint Shop Pro 9 from JascSoftware, and then canal transportation was measured using Solidwork 2014. The data were analyzed by SPSS software version 22. Multivariate statistical analysis general linear model (GLM) was also applied. Bonferroni correction test was used in multiple comparisons and the statistical significance was set to 0.05.
  
  
  
  There was no difference in canal transportation resulted from utilizing PTN files after six multiple uses; in addition, the PTN files showed ability to maintain the original canal anatomy, especially in the apical level, where lowest total mean value of canal center displacement was seen (3 mm level) (0.019 ± 0.017).
  
  
  
  ProTaper Next files can be used to prepare single and multiple canals in a single furcated tooth.
  
  
  
  ProTaper Next nickel-titanium (NiTi) file system is a safe instrument that respects the canal shape, allows practitioners to treat difficult cases with good results, and low risk of separation.
authors.affiliation: PhD, Department of Endodontics, Faculty of Dental Medicine University of Porto, Rua Dr. Manuel Pereira da Silva 4200-393, Porto, Portugal Phone: +351 92005818, e-mail: ranya_elemam@yahoo.co.uk.
authors.forename: Ranya F
authors.initials: RF
authors.lastname: Elemam
authors.affiliation: Department of Endodontics, Faculty of Dental Medicine University of Porto, Porto, Portugal.
authors.forename: J A
authors.initials: JA
authors.lastname: Capelas
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering University of Porto, Porto, Portugal.
authors.forename: Mário A P
authors.initials: MA
authors.lastname: Vaz
authors.affiliation: Laboratory of Optics and Experimental Mechanics, INEGI-Institute of Mechanical Engineering and Industrial Management Porto, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Viriato
authors.affiliation: Faculty of Dental Medicine, University of Porto, EPI Unit-Institute of Public Health University of Porto, Porto, Portugal.
authors.forename: M L
authors.initials: ML
authors.lastname: Pereira
authors.affiliation: Faculty of Dental Medicine, University of Porto, EPI Unit-Institute of Public Health University of Porto, Porto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Azevedo
authors.affiliation: Department of Endodontics, University of Washington School of Dentistry, Washington, USA.
authors.forename: John
authors.initials: J
authors.lastname: West
mesh_terms: D003722:Dental Alloys; D003786:Dental Pulp Cavity; D004867:Equipment Design; D006801:Humans; D009532:Nickel; D018915:Root Canal Preparation; D014025:Titanium; D019227:Tooth Apex
chemical_list: D003722:Dental Alloys; D009532:Nickel; D014025:Titanium
keywords: Canal transportation; Multiple uses; NiTi rotary instruments; PTN, Shaping ability