A preliminary scanning electron microscopic study of root canals after endodontic procedures

By McComb D, Smith DC.

Date: 01/1975
Journal: JOE


To demonstrate the effect of several irrigants used during root canal procedures.


3 groups:

1.Water irrigation.

2.Chemical irrigation- 1% , 6% NaOCl, 6% NaOCl+ 3% H2O2, EDTA, RCPrept, Polyacrylic acid.

3.Sealed chemical irrigations for 24 hours.

Each group had 2 teeth split down the length of the root and examined under scaning electron microscope.


1.All irrigations showed smear layer and debris except for EDTA

2.6% NaOCl+ 3% H2O2 is less effective than NaOCl alone and decreses the effectiveness of EDTA in the apical 1/3

3.RC Prep- More debris remaining than with water irrigation

4. EDTA showed completely smear free surface after 24

Clinical Significance:

EDTA is most effective in terms of removing the smear layer

Nothing can remove the smear layer and debris completely