Reproducibility of a multiplex PCR based method for the detection and semi-quantification of periodontopathogenic species in subgingival plaque samples.

Objective: The aim of the present study was to evaluate the reproducibility of a commercial kit for the detection and semi-quantification of five periodontopathogenic species. Background: A commercial multiplex PCR-based method has recently been validated for the detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Prevotella intermedia. Study design: Sixty-five untreated sites with different probing pocket depths in 20 chronic periodontitis patients were sampled twice by simultaneously applying two sterile paper points. All samples were coded and separately analysed for the detection and semi-quantification of five periodontopathogenic species. Results: The present study indicated acceptable reproducibility of the commercial test for Treponema denticola, Tannerella forsythia and Porphyromonas gingivalis: agreement varied between 70% and 79% in species-positive sites. In contrast, low agreement was found for Actinobacillus actinomycetemcomitans (47%) and Prevotella intermedia (57%). Data analysis indicated, however, that low agreement for these species might have been a consequence of the border line of the detection limit. Conclusion: The results of this reproducibility study support the use of this multiplex PCR-based method for the detection and semi-quantification of periodontopathogens in subgingival plaque samples