Periapical Inflammation after Coronal Microbial
Inoculation of Dog Roots Filled with Gutta-Percha or Resilon.
Shipper G, Teixeira FB, Arnold RR, Trope M.
Drs. Shipper, Trope and Teixeira are affiliated with the Department of
Endodontics, University of North Carolina School of Dentistry, Chapel Hill,
NC. Dr. Roland R. Arnold is Professor, Departments of Diagnostic Sciences
and Periodontology, and Director of Oral Microbiology, UNC School of
Dentistry, Chapel Hill, NC.
A dog model was used to assess and compare in vivo the efficacy of
gutta-percha and AH26 sealer versus Resilon with Epiphany primer and sealer
[Resilon "Monoblock" System (RMS)] filled roots in preventing
apical periodontitis subsequent to coronal inoculation with oral
microorganisms. There were 56 vital roots in the premolars of seven adult
beagle dogs aseptically instrumented, filled, and temporized. The roots were
randomly divided into four experimental groups (Coronal Leakage Model) and
one negative control group and filled as follows: group 1-lateral
condensation of gutta-percha and AH26 sealer (n=12); group 2-vertical
condensation of gutta-percha and AH26 sealer (n=12); group 3-lateral
condensation of RMS (n=12); group 4-vertical condensation of RMS (n=10);
negative control (n=10)-gutta-percha and AH26 sealer or RMS root fillings
using lateral or vertical condensation techniques as in groups 1 to 4.
Positive control-57 additional premolar roots were instrumented, infected
and not filled (beginning of the Entombment Model experiment). The premolars
in groups 1 to 4 were accessed again, inoculated with dental plaque scaled
from the dog's teeth, and temporized. This fresh innoculum of microorganisms
was repeated on two more occasions at monthly intervals. The teeth in the
negative control group were not accessed again and remained undisturbed. On
the 14-wk postcoronal inoculation, dogs were euthanized, and jaw blocks
prepared for histologic evaluation under a light microcope. Mild
inflammation was observed in 82% (18 of 22) of roots filled with
gutta-percha and AH26 sealer that was stastistically more than roots filled
with RMS (19% or 4 of 21) and roots in the negative control (22% or 2 of 9)
(McNemar paired analysis, p < 0.05). The Resilon "Monoblock"
System was associated with less apical periodontitis, which may be because
of its superior resistance to coronal microleakage.