title: Influence of shaft design on the shaping ability of 3 nickel-titanium rotary systems by means of spiral computerized tomography.
abstract: OBJECTIVE
  To evaluate the influence of shaft design on the shaping ability of 3 rotary nickel-titanium (NiTi) systems.
  
  
  METHODS
  Sixty curved mesial canals of mandibular molars were used. Specimens were scanned by spiral tomography before and after canal preparation using ProTaper, ProFile, and ProSystem GT rotary instruments. One-millimeter-thick slices were scanned from the apical end point to the pulp chamber. The cross-sectional images from the slices taken earlier and after canal preparation at the apical, coronal, and midroot levels were compared.
  
  
  RESULTS
  The mean working time was 137.22 +/- 5.15 s. Mean transportation, mean centering ratio, and percentage of area increase were 0.022 +/- 0.131 mm, 0.21 +/- 0.11, and 76.90 +/- 42.27%, respectively, with no statistical differences (P> .05).
  
  
  CONCLUSIONS
  All instruments were able to shape curved mesial canals in mandibular molars to size 30 without significant errors. The differences in shaft designs seemed not to affect their shaping capabilities.
authors.affiliation: Department of Endodontics, Associação Brasileira de Odontologia, Uberlândia, Brazil. marcoversiani@yahoo.com
authors.forename: Marco Aurélio
authors.initials: MA
authors.lastname: Versiani
authors.forename: Elizeu Alvaro
authors.initials: EA
authors.lastname: Pascon
authors.forename: Cássio José Alves
authors.initials: CJ
authors.lastname: de Sousa
authors.forename: Marco Aurélio Gagliardi
authors.initials: MA
authors.lastname: Borges
authors.forename: Manoel Damião
authors.initials: MD
authors.lastname: Sousa-Neto
mesh_terms: D000704:Analysis of Variance; D003722:Dental Alloys; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology; D004867:Equipment Design; D006801:Humans; D008963:Molar; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D018709:Statistics, Nonparametric; D013997:Time Factors; D014025:Titanium; D036542:Tomography, Spiral Computed
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium