title: Evaluation of the Shaping Characteristics of ProTaper Gold, ProTaper NEXT, and ProTaper Universal in Curved Canals.
abstract: BACKGROUND
  This study evaluated the shaping characteristics of the ProTaper Gold system (PTG; Dentsply Maillefer, Ballaigues, Switzerland) and compared it with that of the ProTaper Next (PTN, Dentsply Maillefer) and ProTaper Universal (PTU, Dentsply Maillefer) systems using micro-computed tomographic imaging.
  
  
  METHODS
  Twenty-four mandibular first molars with 2 separate mesial canals were matched anatomically using micro-computed tomographic scanning (SkyScan1174v2; Bruker-microCT, Kontich, Belgium) with a voxel size of 19.6 μm. Canals were prepared with PTG, PTU, or PTN rotary systems to F2 or X2 instruments, respectively, and scanned again. Coregistered images were evaluated for 2- and 3-dimensional morphometric measurements of canal transportation, centering ability, untouched canal walls, and remaining dentin thickness. Data were statistically compared using Kruskal-Wallis and 1-way analysis of variance tests (α = 5%).
  
  
  RESULTS
  Overall, PTN showed significantly higher percentage values of static voxels than PTG and PTU systems (P < .05). Surface area, perimeter, and minor diameter were higher in the PTG and PTU groups than in the PTN group (P < .05). No difference was observed in form factor, roundness, major diameter, aspect ratio, or structure model index (P > .05). PTG (0.11 ± 0.05 mm) and PTN (0.09 ± 0.05 mm) produced significantly less transportation than PTU (0.14 ± 0.07 mm) (P < .05), and the percentage decrease in dentin thickness was significantly lower for PTG (22.67 ± 2.96) and PTN (17.71 ± 5.93%) (P ≥ .05) than PTU (29.93 ± 6.24%) (P < .05).
  
  
  CONCLUSIONS
  PTG and PTN produced less transportation and maintained more dentin than PTU. PTN had less canal wall contact than PTG and PTU, but all file systems were able to instrument moderately curved mesial root canals of mandibular molars without clinically significant errors.
authors: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Canada.
authors: Jason
authors: J
authors: Gagliardi
authors: Department of Restorative Dentistry, Dental School of Ribeirao Preto, University of São Paulo, São Paulo, São Paulo, Brazil.
authors: Marco Aurélio
authors: MA
authors: Versiani
authors: Department of Restorative Dentistry, Dental School of Ribeirao Preto, University of São Paulo, São Paulo, São Paulo, Brazil.
authors: Manoel Damião
authors: MD
authors: de Sousa-Neto
authors: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Canada.
authors: Andres
authors: A
authors: Plazas-Garzon
authors: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Canada. Electronic address: Bettina.basrani@dentistry.utoronto.ca.
authors: Bettina
authors: B
authors: Basrani
mesh_terms: D003722:Dental Alloys; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008334:Mandible; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Canal transportation; micro–computed tomographic imaging; multiple-file system; nickel-titanium instruments; root canal preparation; rotary instruments