Abstract

Periradicular lesions develop as a result of the interaction between root canal irritants and the immune system. The purpose of this study was to investigate the periradicular response of immunodeficient rats to their oral flora. Twenty Sprague-Dawley rats received a total body irradiation dose of 750 cGy one week prior to the investigation. The pulps of the mandibular first molars of these animals and six nonirradiated rats were exposed mechanically with a ½ round bur and left open to the oral cavity. Additional irradiation (350 cGy) was administered bi-weekly to maintain immunosuppression. Periradicular specimens were obtained after two and four weeks, fixed, sectioned, and stained with H & E. The amount of periradicular inflammation was quantified and statistically analyzed using repeated measures ANOVA.

Circulating white cell counts were diminished to 7.1% of control values in immunodeficient rats. At two and four weeks, all animals showed the presence of periradicular pathosis by displaying osseous replacement by granulation tissue, root resorption, and acute inflammatory cells. The immunosuppressed specimens showed immature inflammatory cells and numerous macrophages at four weeks. With respect to lesion size, the difference between the experimental and control group was statistically significant. When examined by factors, immunosuppression was statistically significant but time was not. Immunosuppression caused a trend towards faster formation of larger periradicular lesions. The results indicate that the immune system slows down the spread of root canal infection.

Department

Dentistry

School

Graduate School

First Advisor

Mahmoud Torabinejad

Second Advisor

James Kettering

Third Advisor

Paul McMillan

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2000

Date (Title Page)

3-2000

Language

English

Library of Congress/MESH Subject Headings

Dental Pulp Diseases -- pathology; Dental Pulp Cavity -- immunology; Dental Pulp Exposure

Type

Thesis

Page Count

vii; 57

Digital Format

PDF

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.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

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

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