The purpose of this project was to study the antibacterial effect of the short exposure of 5.25% NaOCl and 17% EDTA on eight strains of Enterococcus faecalis in extracted human teeth. The crowns of 240 single rooted teeth were removed and the canals were instrumented to ISO 0.36. The canals were irrigated with 5.25% NaOCl and 17% EDTA, autoclaved and separated into eight groups of 30 teeth consisting of 20 experimental teeth, 5 positive and 5 negative controls. Each group was inoculated with one of eight different strains of E. faecalis in BHl broth and incubated for four weeks. The canals were then irrigated for 5 minutes with 10 ml 5.25% NaOCl and 1 ml 17% EDTA. The external root surface was decontaminated with a 5 minute soak in 5.25% NaOCl. The roots were then vortexed for 15 seconds in BHl broth. They finally were placed in a vial of BHl broth and incubated for one week. The presence or absence of turbidity was determined and dentin shavings were collected on agar plates from all non-turbid teeth along with the positive and negative controls. They were incubated for 48 hours. The presence of E. faecalis was determined by the presence of white pinpoint colonies on agar plates and Gram staining. The combination of 5.25% NaOCl and 17% EDTA was most effective against strains 19433 and 49452 and least effective against 4082 and 49383. E.faecalis was cultured in 121 of 160 experimental teeth. Based on these results it appears that the short exposure of 5.25% NaOCl and 17% EDTA was ineffective in eliminating E. faecalis infected teeth in the present model.




Graduate Studies

First Advisor

Mahmoud Torabinejad

Second Advisor

Shahrokh Shahahang

Third Advisor

Robert Handysides

Fourth Advisor

Neal Johnson

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Dental Pulp Cavity -- microbiology -- dissertations; Enterococcus Faecalis -- drug effects; Bacteria -- pathogenicity; Humans; Tooth Extraction; Root Canal Irrigants; Root Canal Therapy



Page Count

ix; 62

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives