[A comparative study of root smear layer removal using different pH EDTA salts].
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.
Ma
Rui
R
Department of Stomatology, Shanghai Ninth People's Hospital, Shanghai, 200011, China. marui66@hotmail.com
Liu
Zheng
Z
Zhu
Cai-lian
CL
D004492:Edetic Acid / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000494:pharmacology*; D016369:Smear Layer
D012388:Root Canal Irrigants; D004492:Edetic Acid