title: Microcomputed tomographic evaluation of canal transportation and centring ability of ProTaper Next and Twisted File Adaptive systems.
abstract: OBJECTIVE
  To evaluate canal transportation and centring ability of ProTaper Next (PTN) and Twisted File Adaptive (TFA) systems using microcomputed tomographic (micro-CT) imaging.
  
  
  METHODS
  Twenty isthmus-containing mesial roots of mandibular molars were anatomically matched based on similar morphological dimensions using micro-CT evaluation (resolution of 14.25 μm) and assigned to two experimental groups (n = 10) according to the system used for root canal preparation: PTN and TFA groups. Then, the specimens were scanned again and the matched images of the mesial canals, before and after preparation, were examined at three cross-section levels (3, 5 and 7 mm from the apical end of the root) to analyse canal transportation and centring ratio. Independent-samples t-test was used to compare canal transportation and centring ratio between the groups. All statistical procedures were performed with a significance level set at 5%.
  
  
  RESULTS
  Root canals prepared with either PTN or TFA systems had similar canal transportation and centring ratios at all levels (P > 0.05).
  
  
  CONCLUSIONS
  PTN and TFA had similar results regarding canal transportation and centring ability.
authors.affiliation: Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Duque de Caxias, RJ, Brazil.
authors.forename: E J N L
authors.initials: EJNL
authors.lastname: Silva
authors.affiliation: Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Duque de Caxias, RJ, Brazil.
authors.forename: P T
authors.initials: PT
authors.lastname: Pacheco
authors.affiliation: Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Duque de Caxias, RJ, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Pires
authors.affiliation: Department of Endodontics, Fluminense Federal University (UFF), Niterói, RJ, Brazil.
authors.forename: F G
authors.identifier: http://orcid.org/0000-0001-9972-6861
authors.initials: FG
authors.lastname: Belladonna
authors.affiliation: Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Duque de Caxias, RJ, Brazil.
authors.forename: G
authors.initials: G
authors.lastname: De-Deus
mesh_terms: D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D004867:Equipment Design; D006801:Humans; D066298:In Vitro Techniques; D008963:Molar / Q000000981:diagnostic imaging* / Q000601:surgery*; D018915:Root Canal Preparation / Q000295:instrumentation*; D055114:X-Ray Microtomography / Q000379:methods*
keywords: canal transportation; centring ability; micro-CT; shaping ability