Abstract

Bacterial lipopolysaccharide (LPS) has been implicated in the pathogenesis of pulpal and periapical diseases. Several studies have evaluated the ability of various medicaments and irrigants used during root canal therapy to chemically detoxify LPS. The purpose of this study was to evaluate the ability of some endodontic sealers to detoxify LPS. This investigation compared the quantities of TNF-α released by human monocytes exposed to LPS or LPS pre-treated with sealers. The sealers tested were: Pulp Canal Sealer EWT (PCS), AH Plus (AH), and Sealapex (SA). Ca(OH)2 and water (H2O) were respectively used as the positive and negative control materials. LPS solutions in three concentrations (10, 100, and 1000 ng/ml) and endotoxin-free water were used as the four test solutions. Each sealer and each control was mixed with each four test solutions. The mixtures were kept in vials at 37°C with 5% CO2 for seven days with daily agitation. After incubation, a sample of each mixture was added to a corresponding fresh human monocyte culture. After 4 hours, the supernatants from the exposed cultures were assayed for the concentration of TNF-α using an instant-ELlSA kit. Statistical analyses were performed using the Kruskal-Wallis rank test and Wilcoxon rank sum test.

Results indicated that Ca(OH)2 and SA had similar levels of TNF-α between them, and between all four test solutions. At the 1000 ng/ml concentration, significantly lower TNF-α values were detected in Ca(OH)2 and SA compared with the other materials. AH reduced significantly the levels of TNF-α released when compared to H20 at 10 and 100 ng/ml. PCS was different than H20 at 10 ng/ml only; it showed significantly lower levels. All three LPS concentrations mixed with H2O showed similar levels, which were significantly higher than the levels of endotoxin-free water with H2O. When mixed with endotoxin-free water, the sealers and Ca(OH)2 had similar TNF-α levels compared to H2O.

Based on this study, we concluded that Ca(OH)2 and Sealapex reduced the production of TNF-α by human monocytes exposed to TPS. AH Plus had a more modest effect on the reduction of TNF-alpha production, while Pulp Canal Sealer EWT only had a weak effect.

Department

Dentistry

School

Graduate Studies

First Advisor

Mahmoud Torabinejad

Second Advisor

Nikola Angelov

Third Advisor

David Jaramillo

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2007

Date (Title Page)

5-2007

Language

English

Library of Congress/MESH Subject Headings

Endodontics; Lipopolysaccharide; Root Canal Therapy; Root Canal Irrigants; Dental Pulp Cavity

Type

Thesis

Page Count

x; 56

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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