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Updated: Oct 1, 2026

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Actinomyces species, streptococci, and Enterococcus faecalis in primary root canal infections

José F Siqueira1, Isabela N Rôças, Renata Souto

  • 1Oral Microbiology Laboratory, Institute of Microbiology, Federal University of Rio de Janeiro, RJ, Brazil.

Journal of Endodontics
|May 23, 2002
PubMed

Insights

This study identified key bacteria in root canal infections using molecular methods. Streptococcus constellatus was significantly linked to acute periradicular abscesses.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Dentistry

Background:

  • Primary root canal infections harbor diverse bacterial communities.
  • Accurate identification of these bacteria is crucial for effective treatment.

Purpose of the Study:

  • To determine the prevalence of Actinomyces species, streptococci, and Enterococcus faecalis in primary root canal infections.
  • To utilize molecular genetic methods for precise bacterial detection.

Main Methods:

  • Collected samples from 53 infected teeth, including 27 acute periradicular abscesses.
  • Employed checkerboard DNA-DNA hybridization and polymerase chain reaction (PCR) for bacterial identification.
  • Analyzed DNA from 13 bacterial species using whole genomic DNA probes.

Main Results:

  • All samples tested positive for bacterial DNA via PCR.
  • Streptococci were found in 22.6%, Actinomyces in 9.4%, and E. faecalis in 7.5% of samples.
  • Streptococcus constellatus was the only species significantly associated with acute periradicular abscesses (p < 0.01).

Conclusions:

  • Molecular methods provide accurate insights into the microbial landscape of root canal infections.
  • Specific bacterial species, like S. constellatus, may serve as indicators for acute periradicular abscesses.

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