title: Shaping ability of ProTaper Gold and ProTaper Universal files by using cone-beam computed tomography.
abstract: BACKGROUND
  This study evaluated and compared the shaping ability of ProTaper Gold (PG) (PG; Dentsply, Tulsa Dental Specialties, Tulsa, OK, USA) system with ProTaper Universal (PU) (PU; Dentsply Maillefer, Ballaigues, Switzerland) using cone-beam computed tomography (CBCT) imaging.
  
  
  METHODS
  Forty mesiobuccal canals of mandibular first molars with curvatures of 25-30° were divided into two experimental groups (n = 20) according to the rotary nickel-titanium (NiTi) file system used in canal instrumentation as follows: Group PG and group PU. Canals were scanned before and after instrumentation using CBCT scanner to evaluate root canal transportation and centering ratio at 3, 5, and 7 mm from the apex and volumetric changes. Data were statistically analyzed using independent t-tests and the significance level was set at P < 0.05.
  
  
  RESULTS
  There was no significant difference between PG and PU systems in the mean volume of removed dentine, canal transportation, and centering ratio (P > 0.05).
  
  
  CONCLUSIONS
  The PG and PU NiTi rotary systems showed similar root canal shaping abilities in the preparation of mesial canals of mandibular first molars.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Amr M
authors.initials: AM
authors.lastname: Elnaghy
authors.forename: Shaymaa E
authors.initials: SE
authors.lastname: Elsaka
mesh_terms: D054893:Cone-Beam Computed Tomography; D003722:Dental Alloys; D003762:Dental Instruments; D004867:Equipment Design; D006801:Humans; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium