Aim: To isolate and identify in a Chilean population,
Enterococcus spp.
from root canals with
persistent chronic apical periodontitis (CAP) and to investigate the potential correlation between
the bacteria and the observed clinical features.
Methods: Twenty patients with indication for
endodontic retreatment due to persistent CAP were selected. Data from patient general health
and dental clinical history were recorded. During retreatment, a microbial sample was obtained
from the root canal and inoculated in a selective
Enterococcus medium. Using bacterial cultivation
methods, bacterial isolates belonging to the genus
Enterococcus were identified. The relationship
between the number of colony-forming units of
Enterococcus spp. and patient clinical data was
assessed statistically by the Pearson Chi square and Fisher exact tests. Finally, a Polymerase
Chain Reaction (PCR) assay to determine the most prevalent species of
Enterococcus spp. was
conducted in the clinical samples, and the results were analyzed by a proportion comparison
test.
Results: Enterococcus spp. strains were isolated in 70% of the patients. Most of them
(98.8%) accounted for
Enterococcus faecalis
and only 1.2% for
Enterococcus faecium
. A high
frequency of
E. faecalis was found in teeth with inadequate endodontic treatment or dental crown
restorations.
Conclusions: This study concluded that
E. faecalis is prevalent in root canals with
persistent CAP in a Chilean population.
E. faecium as found in a single case with the poorest root
canal filling. Further studies are still required to investigate the presence of other species, which
may be linked to persistent chronic apical periodontitis.
