Non-radioactively labelled DNA probes for the detection of periodontopathogenic Prevotella and Porphyromonas species.

Digoxigenin-labelled synthetic DNA probes directed against the 16S rRNA were used for the direct detection of the periodontopathogenic bacteria Prevotella intermedia and Porphyromonas gingivalis in subgingival plaque by applying a DNA-RNA dot-blot hybridization procedure. The test was evaluated with 134 plaque samples from 26 patients with adult periodontitis or rapidly progressive periodontitis. The lower limit of detection was 10(4)-10(5) bacteria/specimen. A semiquantitative assessment of the two species in each sample and in the corresponding periodontal site was achieved by this technique. It is possible to examine 80-90 samples within two days with low material costs.