title: Root Canal Transportation and Centering Ability of Nickel-Titanium Rotary Instruments in Mandibular Premolars Assessed Using Cone-Beam Computed Tomography.
abstract: BACKGROUND
  The aim of this study was to evaluate, using cone-beam computed tomography (CBCT), transportation and centralization of different nickel-titanium (NiTi) rotary instruments.
  
  
  METHODS
  One hundred and twenty eight mandibular premolars were selected and instrumented using the following brands of NiTi files: WaveOne, WaveOne Gold, Reciproc, ProTaper Next, ProTaper Gold, Mtwo, BioRaCe and RaCe. CBCT imaging was performed before and after root canal preparation to obtain measurements of mesial and distal dentin walls and calculations of root canal transportation and centralization. A normal distribution of data was confirmed by the Kolmogorov-Smirnov and Levene tests, and results were assessed using the Kruskal-Wallis test. Statistical significance was set at 5%.
  
  
  RESULTS
  ProTaper Gold produced the lowest canal transportation values, and RaCe, the highest. ProTaper Gold files also showed the highest values for centering ability, whereas BioRaCe showed the lowest. No significant differences were found across the different instruments in terms of canal transportation and centering ability (P > 0.05).
  
  
  CONCLUSIONS
  Based on the methodology employed, all instruments used for root canal preparation of mandibular premolars performed similarly with regard to canal transportation and centering ability.
authors.affiliation: Federal University of Goiás Praça Universitária s/n, Setor Universitário, 74605-220 Goiânia, GO, Brazil.
authors.forename: Iussif
authors.initials: I
authors.lastname: Mamede-Neto
authors.affiliation: University of Cuiaba, Avenida Manoel José de Arruda 3.100, Jardim Europa, 78065-900 Cuiabá, MT, Brazil.
authors.forename: Alvaro Henrique
authors.initials: AH
authors.lastname: Borges
authors.affiliation: University of Cuiaba, Avenida Manoel José de Arruda 3.100, Jardim Europa, 78065-900 Cuiabá, MT, Brazil.
authors.forename: Orlando Aguirre
authors.initials: OA
authors.lastname: Guedes
authors.affiliation: University of Cuiaba, Avenida Manoel José de Arruda 3.100, Jardim Europa, 78065-900 Cuiabá, MT, Brazil.
authors.forename: Durvalino
authors.initials: D
authors.lastname: de Oliveira
authors.affiliation: University of Cuiaba, Avenida Manoel José de Arruda 3.100, Jardim Europa, 78065-900 Cuiabá, MT, Brazil.
authors.forename: Fábio Luis Miranda
authors.initials: FL
authors.lastname: Pedro
authors.affiliation: Federal University of Goiás Praça Universitária s/n, Setor Universitário, 74605-220 Goiânia, GO, Brazil.
authors.forename: Carlos
authors.initials: C
authors.lastname: Estrela
keywords: CBCT; Canal Transportation; Centralization; Endodontics; Nickel-titanium Instruments