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Updated: Feb 3, 2026
10:26
Inducing Apical Periodontitis in Mice
Published on: August 6, 2019
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Root Microbiota in Primary and Secondary Apical Periodontitis.
Serge Bouillaguet1, Daniel Manoil1, Myriam Girard2
1Endodontics Unit, Section of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
Frontiers in Microbiology
|October 26, 2018
Summary
This study reveals distinct bacterial profiles in primary and secondary apical periodontitis infections. Understanding these microbial differences, like the prevalence of Fusobacterium nucleatum, can guide targeted treatments for this dental condition.
Area of Science:
- Microbiology
- Dental Science
- Genomics
Background:
- Apical periodontitis is an inflammation of periradicular tissues caused by bacteria in necrotic root canals.
- Primary infections stem from initial pulp necrosis, while secondary infections arise from persistent, inadequately treated root canals.
Purpose of the Study:
- To characterize the intraradicular microbiota in primary and secondary apical periodontitis using 16S rRNA gene amplicon sequencing.
- To identify differences in bacterial composition and interactions between primary and secondary root canal infections.
Main Methods:
- DNA extraction from intraradicular content and dentin samples of extracted teeth with apical periodontitis.
- 16S rRNA gene V3-V4 region sequencing on an Illumina MiSeq platform.
- Bioinformatic analysis including quality filtering, OTU clustering, and taxonomic assignment.
Main Results:
- Fusobacterium nucleatum was the most prevalent and abundant operational taxonomic unit (OTU) in both sample types.
- Microbiota clustered by sample type (dentin vs. intraradicular) and by infection type (primary vs. secondary).
- Secondary infections showed higher Enterococcus faecalis and lower F. nucleatum proportions compared to primary infections.
Conclusions:
- Distinct bacterial communities and interactions characterize primary and secondary intraradicular infections.
- Identifying differentially abundant taxa provides a basis for developing targeted therapeutic strategies against apical periodontitis.
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