Journal of Dental Research, Vol 67, 1342-1345, Copyright © 1988 by International & American Associations for Dental Research Online Journals
The effects of different levels of dietary sucrose on root caries subsequent to gingivectomy in conventional rats infected with Actinomyces viscosus M-100
A. R. Firestone, C. N. Graves and F. F. Feagin
Department of Restorative Dentistry, School of Dentistry, Univeristy of Alabama, Birmingham 35294.
Three groups of weanling, Sprague-Dawley-derived rats were inoculated with
Actinomyces viscosus M-100 and fed powdered diet containing either 67%, 5%,
or 0% confectioner's sugar. Two further groups were fed diet containing 5%
confectioner's sugar and inoculated with Streptococcus sobrinus 6715 or S.
sobrinus 6715 plus A. viscosus M-100. The most coronal 1 mm of gingiva was
removed from maxillary and mandibular right molar quadrants (gingivectomy),
and the animals re-inoculated following gingivectomy. The animals were
killed 64 days following gingivectomy, and the lingual surface of
mandibular first molar roots was measured for exposed root-surface area and
root caries. In the groups of rats infected with A. viscosus M-100, root
caries area was significantly greater in the group fed diet containing 67%
confectioner's sugar. Sucrose level did not significantly affect the amount
of exposed lingual first molar root area regardless of whether the tooth
had been subjected to a gingivectomy. In the groups of rats receiving diet
containing 5% confectioner's sugar, there were no significant differences
in root caries area or exposed root-surface area, regardless of the
infection status of the animals. In the rat model presented here, a high
level of dietary sucrose was a necessary condition for the initiation of
root caries in the absence of other readily fermentable carbohydrates.
