Journal of Dental Research, Vol 71, 470-474, Copyright © 1992 by International & American Associations for Dental Research Online Journals
Periapical innervation of the ferret canine one year after pulpectomy
G. R. Holland
Division of Endodontics, Faculty of Dentistry, University of Alberta, Edmonton, Canada.
Previous studies have shown that, following removal of the dental pulp and
its replacement with a filling material, the nerves in the periapical
region proliferate within an area of chronic inflammation. This study
examined these responses in the ferret in more detail, both quantitatively
and in three dimensions, 12 months after pulpectomy which was followed by
obturation with gutta percha and zinc oxide and eugenol sealer. The results
were compared with the responses after three months. The basic patterns, in
terms of both inflammation and neural proliferation, were similar at the
two time periods. Both the sizes of the inflammatory lesions and the degree
of neural proliferation were lower at 12 months than at three, although the
differences were not significantly different in the small number of
specimens examined. Bacterial stains failed to show bacteria either in the
apical root canal delta or in the periapical area. It is possible that the
persistent inflammation was due to the irritant nature of the obturating
materials used but not due to the original tissue damage, since extraction
sites, by comparison, healed very quickly. Apparently, following endodontic
treatment, chronic periapical inflammation and concomitant neural
proliferation can continue for long periods.
