Reproducibility of a commercially available subgingival plaque sampling strategy and analysis strategy with oligonucleotide probes

Abstract

Objectives: The aim was to evaluate the intra-test agreement of pooled samples from the deepest periodontal pocket of each quadrant with a commercially available test kit based on hybridization of 16S rRNA.

Material and methods: Plaque samples of 50 patients with generalized severe chronic periodontitis before therapy were pooled in two separate vials in order to detect and compare counts of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. Cohen’s κ and interclass correlation coefficients were calculated to judge intra-test agreement.

Results: Cohen’s κ for detection and counts of Tannerella forsythia and Treponema denticola showed a perfect agreement. Porphyromonas ginigivalis was identified in both tests with a substantial agreement, whereas detection of Aggregatibacter actinomycetemcomitans varied in eight patients resulting in a good agreement. Possible confounding factors could not be identified statistically.

Conclusion: Test results of the commercial 16S rRNA test are perfectly reproducible regarding detection of red complex pathogens. Intra-test agreement concerning detection of Aggregatibacter actinomycetemcomitans was less favorable.

Clinical relevance: Detection of certain periodontal pathogens may alter the treatment and lead to prescription of antibiotics parallel to mechanical debridement. It is quite important not to use antibiotics excessively. Thus, the basis for decision-making in favor of antibiotics should be solid.

Keywords:

• Aggregatibacter actinomycetemcomitans
• generalized severe chronic periodontitis
• Porphyromonas gingivalis
• RNA probes
• subgingival plaque
• Tannerella forsythia
• Treponema denticola

Acknowledgements

This study was mostly self-funded by the authors and their institutions. The IAI (Institut für angewandte Immunologie, Zuchwil, Switzerland) provided microbiological tests as well as analysis for second samples.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Notes on contributors

Bernadette Pretzl is an Associate Professor in the Section of Periodontology, Department of Operative Dentistry, University Hospital in Heidelberg. She conducted clinical examinations, retrieved microbiological samples and also wrote the manuscript.

Jule Paul was a student at the Department of Operative Dentistry, University Hospital in Heidelberg. She entered data into files, searched patients? files and performed preliminary descriptive analyses.

Diana Krigar was Associate Professor in the Section of Periodontology, Department of Operative Dentistry, University Hospital in Heidelberg and works in her private practive, now. She conducted most of the clinical examinations and retrieved microbiological samples.

Lorenz Uhlmann is a statistician at the Institute of Medical Biometry and Informatics (IMBI) of zhe University Hospital in Heidelberg. He conducted all statistical analyses.

Peter Eickholz is head of the Department of Periodontology, Center of Dentistry and Oral Medicine in Frankfurt. He initiated and planned the study, wrote study protocols, and revised the manuscript.

Bettina Dannewitz is an Associate Professor in the Section of Periodontology, Department of Operative Dentistry, University Hospital in Heidelberg as well as the Department of Periodontology, Center of Dentistry and Oral Medicine in Frankfurt. She was responsible for the study and revised the manuscript.