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VOLUME 8 , ISSUE 1 ( January, 2007 ) > List of Articles


A Scanning Electron Microscopic Evaluation of Root Canal Wall Cleanliness after Calcium Hydroxide Removal Using Three Irrigation Regimens

Alfred Naaman, Etienne Medioni, Hrant Kaloustian, Hani Fouad Ounsi, Nada Naaman-Bou Abboud, Catherine Ricci

Citation Information : Naaman A, Medioni E, Kaloustian H, Ounsi HF, Abboud NN, Ricci C. A Scanning Electron Microscopic Evaluation of Root Canal Wall Cleanliness after Calcium Hydroxide Removal Using Three Irrigation Regimens. J Contemp Dent Pract 2007; 8 (1):11-18.

DOI: 10.5005/jcdp-8-1-11

License: CC BY-NC 3.0

Published Online: 01-01-2007

Copyright Statement:  Copyright © 2007; Jaypee Brothers Medical Publishers (P) Ltd.



The aims of this in vitro study were to evaluate debris and smear layer elimination capability effectiveness of 5.25% sodium hypochlorite (NaOCl) after calcium hydroxide removal from the root canal and to determine if ethylenediaminetetraacetic acid (EDTA) and citric acid have any additional effects on debris and smear layer removal.

Methods and Materials

All irrigation regimens are associated with ultrasonics. Thirty-six pulpless single-rooted teeth were divided into three groups on the basis of the irrigation regimen, namely 5.25% NaOCl alone, 5.25% NaOCl with 17% EDTA pH 7 (NaOCl-EDTA), and 5.25% NaOCl with 50% citric acid (NaOCl-CA). All root canals were instrumented with the Protaper® rotary system (Dentsply-Maillefer, Ballaigues, Switzerland) using a crowndown approach. The apical foramen of each tooth was enlarged to a size 30 with a 0.09 taper. After longitudinal sectioning, the dentin walls were microphotographed using scanning electron microscopy (SEM) at a 1500X magnification. Using a grid and a 5-step scale these microphotographs were scored by three investigators in order to evaluate debris and smear layer residuals. Data were statistically evaluated using Kruskal-Wallis and Mann-Whitney tests.


In the coronal third the lowest score obtained with NaOCl-CA was similar to NaOCl-EDTA. When using NaOCl-EDTA, mean debris scores were similar to the control group (NaOCl) and lower than NaOCl-CA in the middle and apical thirds. Regarding the mean smear layer score, NaOCl-CA was the lowest in the coronal, middle, and apical thirds with a statistically significant difference (p< 0.001).


When the total surface of the root was evaluated, NaOCl-EDTA was superior in removing debris, but the association of NaOCl-CA enabled the most effective removal of the smear layer.


Naaman A, Kaloustian H, Ounsi HF, Naaman-Bou Abboud N, Ricci C, Medioni E. A Scanning Electron Microscopic Evaluation of Root Canal Wall Cleanliness after Calcium Hydroxide Removal Using Three Irrigation Regimens. J Contemp Dent Pract 2007 January;(8)1:011-018.

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  1. Reduction of intracanal bacteria using GT rotary instrumentation, 5.25% NaOCl, EDTA and Ca(OH)2. J Endod 2005;31:359-363.
  2. Anaerobic tissue dissolving abilities of calcium hydroxide and sodium hypochlorite. J Endod 1995;21:613-616.
  3. Effect of calcium hydroxide dressing on seal of permanent root filling. Endod Dent Traumatol 1997;13:281-284.
  4. Disinfection by endodontic irrigants and dressings of experimentally infected dentinal tubules. Endod Dent Traumatol 1990;6:142-149.
  5. The antibacterial effect of camphorated paramonochlorophenol, camphorated phenol and calcium hydroxide in the treatment of infected root canals. Endod Dent Traumatol 1985;1:170-175.
  6. A comparison of antimicrobial effects of calcium hydroxide and iodine-potassium iodide. J Endod 1985;10:454-456.
  7. The comparative effect of calcium hydroxide. Oral Surg 1991;72:101-104.
  8. In vitro determination of direct antimicrobial effect of calcium hydroxide. J Endod 1998;24:15-17.
  9. Intracanal medicaments: evaluation of the antibacterial effects of chlorhexidine, metronidazole and calcium hydroxide associated with three vehicles. J Endod 1997;23:167-169.
  10. Evaluation of the antibacterial activities of calcium hydroxide, chlorhexidine and camphorated paramonochlorphenol as intracanal medicament. A clinical and laboratory study. J Endod 1997;23:297-300.
  11. Effect of calcium hydroxide on bacterial lipopolysaccharides. J Endod 1993;2,76-78
  12. Alteration of biological properties of bacterial lipopolysaccharides by calcium hydroxide treatment. J Endod 1994;20:127-129.
  13. Microbiologic analysis of teeth with failed endodontic treatment and the outcome of conservative re-treatment. Oral Surg, Oral med Oral Pathol, Oral Radiol, Endod 1998;85:86-93.
  14. Effect of calcium hydroxide and four irrigation regimens on instrumented and uninstrumented canal wall topography. J Endod 1999;25:93-98.
  15. Effect of calcium hydroxide as an intracanal dressing on apical leakage. Int Endod J 1998;31:173-177.
  16. Retief H, Barfield RD, Lacefield WR, Soong SJ. Effects of calcium hydroxide paste as intracanal medicament on apical seal. Int Endod J 1990;16:369-374.
  17. Effects of irrigation on debris and smear layer on canal walls prepared by two rotary techniques: A scanning electron microscopic study. J Endod 2000;26:6-10.
  18. The antimicrobial effect of calcium hydroxide as a short term intracanal dressing. Int Endod J 1991;24:119-125.
  19. Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis. Int Endod J 1997;30:297-306.
  20. The effectiveness of various disinfectants used as endodontic intracanal medications: an in vitro study. J Endod 2002;28:163-177.
  21. Additive antimicrobial activity of calcium hydroxide and chlorhexidine on common endodontic bacterial pathogens. J Endod 2003;29,340-345
  22. An immunohistological study of the localization of bacteria invading root pulpal walls of teeth with periapical lesions. J Endod 2003;29:194-200.
  23. Incomplete calcium hydroxide removal from the root canal: a case report. Int Endod J 1997; 30: 418-421.
  24. Interaction of calcium hydroxide with zinc oxideeugenol type sealers: a potential clinical problem. J Endod 1997;23:43-48.
  25. Removal efficiency of calcium hydroxide dressing from the root canal. J Endod 1999;25:85-88.
  26. A preliminary scanning electron microscopic study of root canals after endodontic procedures. J Endod 1975;1:238-242.
  27. A comparative study of the removal of smear layer by three endodontic irrigants and two types of laser. Int Endod J 1999;32:32-39.
  28. Effect of removal of the smear layer on apical microleakage. J Endod 2001;27:351-353.
  29. Clinical implications of the smear layer in endodontics: a review. Oral Radiol Endod 2002;94:658-666.
  30. Root canal cleanliness after preparation with different endodontic handpieces and hand instruments: a comparative SEM investigation. J Endod 1997;23:301-306.
  31. Scanning electron microscope study comparing four root canals preparations techniques in small curved canals. Int Endod J 1997;30:323-331.
  32. Efficacy of three techniques in cleaning the apical portion of curved root canals. Oral Surg Oral Med Oral Path Oral Radiol Endod 1995;79:492-496.
  33. A scanning electron microscopic evaluation of root canal debridement using saline, sodium hypochlorite, and citric acid. J Endod 1984;10:525-531.
  34. The effectiveness of three irrigating solutions on root canal cleaning after hand and mechanical preparation. Int Endod J 1997;30:51-57.
  35. The efficacy of several irrigant solutions for endodontics: a scanning electron microscopic study. Oral Surg Oral Med and Oral Pathol 1981;52:197-204.
  36. A study on chemical preparation in endodontic therapy. Part II. Various properties of EDTA, phenosulfonic acid and citric acid. Aichi-Gakuin. Journal of Dental Science (in Japanese) 1985;23:455-466.
  37. In vitro inhibitory effect of EGTA on macrophage adhesion: endodontic implications. J Endod 2003;29:211-213.
  38. The disodium salt of EDTA inhibits the binding of vasoactive intestinal peptide to macrophage membranes: endodontic implications. J Endod 1996;22:337-340.
  39. Effects on smear layer and debris removal with varying volumes of 17% REDTA after rotary instrumentation. J Endod 2005;31:536-538.
  40. Root canal irrigation with citric acid solution. J Endod 1996;22:27-29.
  41. Effectiveness of 1mol L-1 citric acid and 15% EDTA irrigation on smear layer removal. Int Endod J 2000; 33: 46-52.
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