Journal of Dental Research, Vol 63, 1003-1005, Copyright © 1984 by International & American Associations for Dental Research Online Journals
An SEM study of posts cemented with an unfilled resin
M. Goldman, R. DeVitre, R. White and D. Nathanson
Post preparations in two groups of endodontically treated anterior teeth
were completed. In Group I, the preparation was rinsed with 2 ml of 5.25%
NaOCL. In Group II, the preparation was rinsed with 1 ml of 17% EDTA,
followed by 1 ml of 5.25% NaOCl. A plastic post was fitted and cemented
with an unfilled resin. After polymerization, the teeth were decalcified in
5% nitric acid. The decalcified structured was dissolved away with 5.25%
NaOCl, leaving a model of the cemented post. This was examined by SEM to
determine the extent of resin penetration into the dentinal tubules. In
Group I, most of the post was smooth, and there was penetration only in
small, random areas. In Group II, there was penetration into the tubules
the full length and circumference of the post. Such penetration provides a
very strong mechanical lock that enhances the tensile strength of the
cemented post. Removing the smeared layer and then cementing a post with a
Bis-GMA resin results in greatly increased tensile strength, even with
shorter posts.
