title: Influence of root canal taper on its cleanliness: a scanning electron microscopic study.
abstract: BACKGROUND
  Taper is a factor that determines final root canal dimensions and, consequently, the dimensions of the space for the cleaning action of irrigants. Therefore, the aim of the present study was to investigate the influence of taper on root canal cleanliness.
  
  
  METHODS
  Root canals of 45 mandibular incisors were divided into 3 groups and prepared with GT rotary files to apical preparation size 30 and final taper 0.04, 0.06, and 0.08, respectively. Irrigation with 2.5% NaOCl was performed after each file. The final irrigation sequence was 10 mL 17% ethylenediaminetetraacetic acid, followed by 10 mL 2.5% NaOCl and 10 mL saline solution. The presence of debris and smear layer on root canal walls was evaluated under the scanning electron microscope with the use of a 4-category scale system.
  
  
  RESULTS
  The presence of debris was minimal in all groups. Statistical analysis for the presence of smear layer showed no significant differences between the groups, whereas a significant difference was detected between the apical and middle thirds of each group.
  
  
  CONCLUSIONS
  Under the conditions of this study, root canal preparation with tapers 0.04, 0.06, or 0.08 did not affect canal cleanliness. Debris removal was almost complete for all tapers, whereas smear layer was not removed, especially from the apical part of the canals.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, University of Athens, Athens, Greece. iarvaniti@yahoo.com
authors.forename: Ioanna S
authors.initials: IS
authors.lastname: Arvaniti
authors.forename: Marouan G
authors.initials: MG
authors.lastname: Khabbaz
mesh_terms: D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure; D004311:Double-Blind Method; D004492:Edetic Acid / Q000627:therapeutic use; D006801:Humans; D007180:Incisor; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D016369:Smear Layer; D012965:Sodium Chloride; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000648:ultrastructure
chemical_list: D012388:Root Canal Irrigants; D012965:Sodium Chloride; D004492:Edetic Acid; D012973:Sodium Hypochlorite