In vitro bacterial penetration of coronally unsealed endodontically treated teeth

By Torabinejad M, Borasmy U, Kettering JD

Date: 11/1990
Journal: JOE


Purpose: to determine the length of time needed for bacteria to penetrate a standardized length of obturated root canals which were intentionally exposed to one of two species of microorganism

N= 45 maxillary anteriors


•The teeth were cleaned, shaped (step-back, MAF:#40), and then obturated by lateral condensation with GP and Roth’s sealer (l0 mm of the filling material remained in the canal)

•The positive controls were filled with single cone and no sealer

•Two layers of fingernail polish were applied to the outside of the root except for 1 mm at the apex.

•By preparing a special apparatus (Fig.1), the coronal portions of the root filling materials were placed in contact with and Proteus vulgaris (G1) and Staphylococcus epidermidis (G 2)

•The number of days required for these bacteria to penetrate the entire root canals was determined

Most highlighted Results:

•For group 1 (Proteus vulgaris ), the average length of time for leakage was 48.6 days

•For group 2 (Staphylococcus epidermidis), the average was 24.1 days (significant difference)

•Over 50% of the root canals were completely contaminated after 42-day exposure to P. vulgaris but after 19 days for Staphylococcus epidermidis