title: Endodontic shaping performance using nickel-titanium hand and motor ProTaper systems by novice dental students.
abstract: OBJECTIVE
  Preparing a continuous tapering conical shape and maintaining the original shape of a canal are obligatory in root canal preparation. The purpose of this study was to compare the shaping performance in simulated curved canal resin blocks of the same novice dental students using hand-prepared and engine-driven nickel-titanium (NiTi) rotary ProTaper instruments in an endodontic laboratory class.
  
  
  METHODS
  Twenty-three fourth-year dental students attending China Medical University Dental School prepared 46 simulated curved canals in resin blocks with two types of NiTi rotary systems: hand and motor ProTaper files. Composite images were prepared for estimation. Material removed, canal width and canal deviation were measured at five levels in the apical 4 mm of the simulated curved canals using AutoCAD 2004 software. Data were analyzed using Wilcoxon's rank-sum test.
  
  
  RESULTS
  The hand ProTaper group cut significantly wider than the motor rotary ProTaper group in the outer wall, except for the apical 0 mm point. The total canal width was cut significantly larger in the hand group than in the motor group. There was no significant difference between the two groups in centering canal shape, except at the 3 mm level.
  
  
  CONCLUSIONS
  These findings show that the novice students prepared the simulated curved canal that deviated more outwardly from apical 1 mm to 4 mm using the hand ProTaper. The ability to maintain the original curvature was better in the motor rotary ProTaper group than in the hand ProTaper group. Undergraduate students, if following the preparation sequence carefully, could successfully perform canal shaping by motor ProTaper files and achieve better root canal geometry than by using hand ProTaper files within the same teaching and practicing sessions.
authors.affiliation: Faculty of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ming-Gene
authors.initials: MG
authors.lastname: Tu
authors.forename: San-Yue
authors.initials: SY
authors.lastname: Chen
authors.forename: Heng-Li
authors.initials: HL
authors.lastname: Huang
authors.forename: Chi-Cheng
authors.initials: CC
authors.lastname: Tsai
mesh_terms: D004708:Endodontics / Q000193:education* / Q000295:instrumentation*; D009532:Nickel; D018915:Root Canal Preparation; D013335:Students, Dental; D014025:Titanium
chemical_list: D009532:Nickel; D014025:Titanium