title: [A comparative study of root smear layer removal using different pH EDTA salts].
abstract: OBJECTIVE
  To evaluate the effect of different pH EDTA salts on removing root canal smear layers.
  
  
  METHODS
  Sixty human teeth with single root were instrumented using step-back technique, then were irrigated with several irrigating solutions including A: 0.9% saline; B: 5.25% NaOCl +3% H2O2; C: 15% EDTA (pH = 6.5); D: 15% EDTA (pH = 13); E: 15% EDTA (pH = 6.5) 25% NaOCl +3% H2O2; F: 15% EDTA (pH = 13) 25% NaOCl +3% H2O2. After the teeth were split, the root canal walls were examined with scanning electron microscopy at the coronal, middle and apical thirds for smear layer removal.
  
  
  RESULTS
  Except A and B group, all the groups were effective on removing smear layer at the coronal, middle thirds of the root canal, group C had a stronger effect to remove smear layer than group D (P < 0.05), group E was the most effective among these groups. However, these groups were all ineffective on removing smear layer at the apical thirds of root canal.
  
  
  CONCLUSIONS
  15% EDTA (pH = 6.5) 25% NaOCl +3% H2O2 was the most effective irrigation on removing smear layer.
authors.affiliation: Department of Stomatology, Shanghai Ninth People's Hospital, Shanghai, 200011, China. marui66@hotmail.com
authors.forename: Rui
authors.initials: R
authors.lastname: Ma
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Cai-lian
authors.initials: CL
authors.lastname: Zhu
mesh_terms: D004492:Edetic Acid / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000494:pharmacology*; D016369:Smear Layer
chemical_list: D012388:Root Canal Irrigants; D004492:Edetic Acid