Detection of specific periodontal microorganisms from bacteraemia samples after periodontal therapy using molecular-based diagnostics.

AIM: The aim of this study was to assess the presence of subgingival pathogens in peripheral blood samples from periodontitis patients before and after scaling and root planing (Sc/RP) using nested polymerase chain reaction (nested PCR).
MATERIALS AND METHODS: Peripheral blood samples were obtained from 42 patients with severe generalized chronic or aggressive periodontitis. In each patient, four samples of peripheral blood were drawn at different times: immediately before the Sc/RP procedure; immediately after Sc/RP; 15 and 30 min. post-Sc/RP. Blood samples were analysed for bacteraemia with anaerobic culturing and nested PCR, using universal bacterial primers that target the 16S-rRNA gene of most bacteria, subsequently re-amplified with specific primers to Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Eikenella corrodens, Campylobacter rectus and Prevotella intermedia, using a modified phenol-chloroform method for DNA extraction.
RESULTS: Presence of specific periodontal pathogens in peripheral blood after treatment was detected in 54.8% of the patients, in 47.6% with anaerobic culturing and in 19% with nested PCR. In 16.6%, the periodontal pathogens were detected before Sc/RP. P. gingivalis and A. actynomicetemcomitans were the pathogens most frequently detected in the bloodstream before and after Sc/RP.
CONCLUSIONS: Nested PCR demonstrated the presence of DNA from periodontal pathogens in blood samples in severe periodontitis patients before, during and after periodontal therapy. The use of these molecular-based techniques may improve the accuracy from the results obtained by haemoculture.