Numerous studies have examined coronal leakage with in vitro protocols. A search of the literature showed the absence of a long term in vivo, histologic study, examining the effect of coronal and/or radicular leakage on periradicular health.

The purpose of this study was to evaluate the effect of obturation and / or coronal seal in preventing the formation of periradicular lesions in dogs over time. The study was conducted on six beagle dogs. Premolars were cleaned and shaped. Sixteen roots in each dog were randomly assigned to one of four treatment groups of equal size. Group one was obturated using warm vertical condensation with sealer, and had MTA placed into the upper two millimeters of the canal and filling the pulp chamber. The second group was obturated and had no coronal restoration placed. Group three was cleansed and shaped, not obturated and had an Intermediate Restorative Material (IRM) filling placed coronally. Group four was cleansed and shaped, not obturated and had Mineral Trioxide Aggregate placed as a coronal seal.

At 6, 12 and 24 weeks post-operatively, two dogs were euthanized at each time period. Six micron thick sagital sections through the roots were taken, and evaluated for the presence of periradicular lesions.

The size of any bony lesion and the degree of inflammation were evaluated microscopically and measured with morphometric analysis. Analysis of variance, with four treatments and three time periods was used.

There was a statistically significant difference (95% confidence level) in the degree of inflammation and the size of the lesions between the two treatments with well sealed coronal access (MTA) and the two groups without permanently sealed accesses. These results confirm the need for, and emphasize the importance of proper restoration of endodontically treated teeth.




Graduate School

First Advisor

Mahmoud Torabinejad

Second Advisor

Leif Bakland

Third Advisor

Paul Mc Millan

Fourth Advisor

Hong Ming Tang

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Endodontics; Root Canal Obsturation; Root Canal Filling Materials; Root Canal Therapy



Page Count

vi; 41

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