Bacterial Viability in Persistent Apical Periodontitis: A Systematic Review.
D Nascimento1, I C Guedes1, L M Brand1
1Basic Research Center, Dentistry School, UFRGS, Porto Alegre, Brazil.
Journal of Endodontics
|July 27, 2025
Summary
Viable microorganisms are present in persistent apical periodontitis, a condition often unresponsive to treatment. This systematic review confirms bacterial presence, though their exact location remains unclear.
Area of Science:
- Endodontics
- Microbiology
- Oral Pathology
Background:
- Apical inflammatory lesions stem from microbial infections.
- Persistence of these lesions despite treatment is not fully understood.
- This review focuses on viable microorganisms in persistent apical periodontitis.
Purpose of the Study:
- To systematically review evidence on viable microorganisms in persistent apical periodontitis.
- To analyze the role of microbial presence in treatment-resistant apical lesions.
Main Methods:
- Comprehensive literature search across multiple databases (MEDLINE/PubMed, EMBASE, Scopus, Web of Science, Cochrane Library, CAPES, grey literature).
- Inclusion limited to studies obtaining periapical tissue samples during apical surgery.
- Quality assessment of included studies using Joanna Briggs Institute Checklist.
Main Results:
- Four studies were selected from 522 initial results.
- Viable microorganisms were detected in persistent apical periodontitis.
- Bacterial viability confirmed by cell culture (1 study) and RNA-based methods (3 studies).
- RNA-based studies showed methodological heterogeneity.
- Diverse microbial populations characterize these infections.
Conclusions:
- Evidence supports the presence of viable bacteria in persistent apical periodontitis.
- The precise location of bacteria (within lesion, intra-radicular, or extra-radicular) requires further investigation.
- Understanding microbial location is crucial for explaining lesion persistence.
