A Scanning Electron Microscopic Evaluation of Root Canal Debridement Using Saline, Sodium Hypochlorite, and Citric Acid

By Baumgartner J, Brown C, Mader C, Peters DD, Shulman J

Date: 06/1985
Journal: JOE


Purpose: to evaluate statistically the ability of saline (0.9% sodium chloride), 5.25% NaOCI, and 50% citric acid irrigation solutions, used either alone or in various combinations, to remove the superficial debris and the smeared layer during root canal preparation

 N= 36 distal roots of extracted human mandibular molars


oSize 10 K-file to pre-determine WL (-1 mm from foramen), Step-back instrumentation

oSample randomly divided into 6 groups (n=6) following irrigation protocol

oG1: 0.9% Saline,

G2: 5.25% NaOCl,

G3: 50% Citric Acid,

G4: 5.25% NaOCl, 50% Citric Acid,

G5: 50% Citric Acid, 5.25% NaOCl,

G6: 5.25% NaOCl final recapitulation with #25 K-file after drying.

oRoots longitudinally grooved, split in half and prepared for SEM

Most highlighted Results:

NaOCI was significantly better than citric acid in removing superficial debris from the apical third.

Citric acid significantly better than NaOCI in removing smeared layer from both middle and apical third

•Combination of organic and inorganic solvents (NaOCl and Citric Acid) have been recommended for removal of superficial debris and smeared layer.

•Final recapitulation increased amount of superficial debris

•Use of NaOCl alone did not remove the smeared layer

Clinical significance

No single irrigation solution could dissolve organic and inorganic tissues. Combination is advised.