title: The effect of different concentrations of EDTA on instrumented root canal walls.
abstract: OBJECTIVE
  The purpose of this study was to investigate smear layer removal and erosive capacity of different concentrations of EDTA on instrumented root canal walls.
  
  
  METHODS
  Forty single-rooted teeth were instrumented using step-back technique and 2.5% NaOCl. The teeth were randomly divided into 4 groups, and final flushes were preformed with different concentrations of EDTA (15%, 10%, 5%, and 1%). All specimens were prepared for scanning electron microscope evaluation.
  
  
  RESULTS
  The results showed that there was no significant difference on the smear layer removal between different concentrations of EDTA (P = .1959). Only coronal versus apical thirds showed significant difference regarding presence of smear layer (P = .0176). Whereas 15%, 10%, and 5% EDTA solutions demonstrated similar erosion patterns on the root canal walls (P > .05), 1% EDTA caused restricted erosion (P < .0001). There was no significant difference among the regions in terms of erosion (P = .6399).
  
  
  CONCLUSIONS
  Lower concentrations of EDTA can be recommended for clinical usage to avoid excessive erosion of root canal dentin.
authors.affiliation: Division of Endodontology, School of Dentistry, Ege University, Izmir, Turkey. bilge.hakan.sen@ege.edu.tr
authors.forename: Bilge Hakan
authors.initials: BH
authors.lastname: Sen
authors.forename: Ozlem
authors.initials: O
authors.lastname: Ertürk
authors.forename: Beyser
authors.initials: B
authors.lastname: Pişkin
mesh_terms: D002614:Chelating Agents / Q000008:administration & dosage* / Q000494:pharmacology; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure; D004492:Edetic Acid / Q000008:administration & dosage* / Q000494:pharmacology; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000008:administration & dosage* / Q000494:pharmacology; D018915:Root Canal Preparation / Q000379:methods*; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D002614:Chelating Agents; D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite