title: Comparison of three techniques for preparing oval-shaped root canals.
abstract: BACKGROUND
  This study compared three techniques for preparing oval-shaped root canals: Anatomic Endodontic Technology (AET), hand instruments (Hedström files; Dentsply Maillefer, Ballaigues, Switzerland), and rotary nickel-titanium (EndoWave; Morita, Osaka, Japan) instruments with regard to cleaning ability and final canal shape.
  
  
  METHODS
  Three groups each of 13 extracted human mandibular premolars with oval-shaped canals were used. After canal preparation, teeth were sectioned at three levels (coronal, middle, and apical), photographed to assess cross-sectional canal shape, and processed for histologic evaluation of canal wall planing and the presence of debris.
  
  
  RESULTS
  None of the techniques resulted in completely prepared and cleaned canals. No significant difference was found among the three techniques with regard to untouched surface, cross-sectional area, remaining fins, and canal shape at the three levels. Rotary NiTi instruments resulted in significantly less debris in the apical third compared with AET and hand instrumentation.
  
  
  CONCLUSIONS
  AET did not perform better than rotary NiTi or hand instruments in oval-shaped canals.
authors.affiliation: Melbourne Dental School, University of Melbourne, Melbourne, Australia; Department of Conservative Dentistry, Jordan University of Science and Technology, Irbid, Jordan. n.taha@just.edu.jo
authors.forename: Nessrin A
authors.initials: NA
authors.lastname: Taha
authors.forename: Toshiko
authors.initials: T
authors.lastname: Ozawa
authors.forename: Harold H
authors.initials: HH
authors.lastname: Messer
mesh_terms: D003646:Debridement / Q000295:instrumentation* / Q000379:methods; D003754:Dental High-Speed Equipment; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000601:surgery; D006801:Humans; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*