Abstract

This study evaluated the effect of residual gutta percha on the retention strength of prefabricated post cemented with four different cements. Forty intact mandibular single canal canines or premolars were selected for standardized size and quality, endodontically treated, and decoronated to the cementoenamel junction. A post space was prepared to accommodate Para post XP size 4 (Coltene, Whaledent Inc., Cuy Falls, Ohio) to a depth of 8 mm. The Obtura heated gutta percha system was used to inject a very thin line of gutta percha along one lateral wall to the depth of the future post. Forty obturated teeth were randomly divided into four groups. Four different cements were used in each group to cement the posts as follows.

Posts in group 1 were cemented with zinc phosphate cement (Fleck's, Mizzy Inc Cherry Hill NJ). Posts in group 2 were cemented with glass ionomer cement (Ketac-Cem (Applicap capsule 3M ESPE, Dental product, ST. Paul MN). Posts in group 3 were cemented with resin modified glass ionomer cement (Rely-X, 3M ESPE, Dental Product, St. Paul MN). And posts in group 4 were cemented with Composite resin cement (Hi-X, Bisco, Irving Park Road, Schaumburg, IF). The cements were mixed according to the manufacturer's instructions. The teeth were then mounted in a cylinder embedded with epoxy resin to enable subsequent post removal in a direction parallel to the long axis of the para post. The specimens were mounted on the instron machine and posts engaged by a retentive grip to perform the pull test. A constantly increasing tensile force was applied at a crosshead speed of 0.5 lbs/inch2 to the posts until failure. The force required to remove the posts were recorded in lbs/inch2.

Complete removal of posts from the canals were achieved successfully in all the specimens in groups 1-3. Removal of the posts from the canals in group 4 was not achieved. Subsequently, further testing of group 4 specimens was not feasible.

Specimens of groups 1 to 3 were further tested without the existence of the gutta percha on the lateral walls of the canals and were referred to as group 1B, 2B, 3B respectively. Results from these tests were recorded and compared to evaluate the effect of the remaining gutta percha on the tensile strength necessary to pull the posts from the canals.

The same steps followed in the previous cementation of groups 1-3 were followed again except that post space was free from the gutta percha on the lateral walls. Following the same testing protocol described earlier the specimens were tested to failure. The forces required to remove the posts were recorded and then statistically analyzed using Mann-Whitney U and Kruskal-Wallis Ranks tests at the significance level of α = 0.05. Residual gutta percha present in the post space indicated a statistically significant difference in retention strength among the groups p < 0.0001. There was also a significant difference in the retention strength among groups 1B, 2B and 3B p = 0.008. There was no statistically significant difference in retention strength between specimens cemented with resin modified glass ionomer cement (Rely-X) with or without gutta percha present p = 0.156.

LLU Discipline

Prosthodontics

Department

Prosthodontics

School

Graduate Studies

First Advisor

Mathew T. Kattadiyil

Second Advisor

Wayne V. Campagni

Third Advisor

Robert Handysides

Fourth Advisor

Jay Kim

Fifth Advisor

Carlos Muñoz-Viveros

Sixth Advisor

Jose Torres

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2008

Date (Title Page)

6-2008

Language

English

Library of Congress/MESH Subject Headings

Gutta-Percha -- standards; Root Canal Obturation -- methods; Root Canal Filling Materials -- analysis; Dental Cements; Endodontics -- methods

Type

Thesis

Page Count

x; 32

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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