title: Comparison of canal transportation in simulated curved canals prepared with ProTaper Universal and ProTaper Gold systems.
abstract: OBJECTIVE
  The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison.
  
  
  METHODS
  Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at α = 5%.
  
  
  RESULTS
  Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001).
  
  
  CONCLUSIONS
  PTG system produced overall less canal transportation in the curved portion when compared to PTU system.
authors.affiliation: Department of Endodontics, Grande Rio University (UNIGRANRIO) School of Dentistry, Rio de Janeiro, RJ, Brazil.
authors.forename: Emmanuel João Nogueira Leal
authors.initials: EJ
authors.lastname: Silva
authors.affiliation: Department of Endodontics, Grande Rio University (UNIGRANRIO) School of Dentistry, Rio de Janeiro, RJ, Brazil.
authors.forename: Brenda Leite
authors.initials: BL
authors.lastname: Muniz
authors.affiliation: Department of Endodontics, Grande Rio University (UNIGRANRIO) School of Dentistry, Rio de Janeiro, RJ, Brazil.
authors.forename: Frederico
authors.initials: F
authors.lastname: Pires
authors.affiliation: Department of Endodontics, Grande Rio University (UNIGRANRIO) School of Dentistry, Rio de Janeiro, RJ, Brazil.
authors.forename: Felipe Gonçalves
authors.initials: FG
authors.lastname: Belladonna
authors.affiliation: Department of Paediactric Dentistry, Rio de Janeiro Federal University, Rio de Janeiro, RJ, Brazil.
authors.forename: Aline Almeida
authors.initials: AA
authors.lastname: Neves
authors.affiliation: Department of Endodontics, Federal University of Maranhão School of Dentistry, São Luis, MA, Brazil.
authors.forename: Erick Miranda
authors.initials: EM
authors.lastname: Souza
authors.affiliation: Department of Endodontics, Grande Rio University (UNIGRANRIO) School of Dentistry, Rio de Janeiro, RJ, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: De-Deus
keywords: Canal transportation; ProTaper Gold; Root canal instrumentation