Prevalence of Treponema denticola and Porphyromonas gingivalis in plaque from periodontally-healthy and periodontally-diseased sites.

Intracrevicular plaque from periodontally-healthy individuals who had refrained from oral hygiene measures for 24 h prior to sampling, and subgingival plaque from diseased sites of patients with chronic periodontitis were screened by ELISA for the presence of Porphyromonas gingivalis and Treponema denticola. The samples were also subjected to the PerioScan test to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA). Of the 141 samples from periodontally-healthy sites, 73% contained T. denticola antigens and 78% P. gingivalis antigens, compared to 43% and 59%, respectively, in plaque samples from the 159 diseased sites. A positive reaction in the PerioScan test was obtained in 89% of plaque samples from diseased sites and in 60% of those from healthy sites. The correlation between the results of the two assays was poor in the case of intracrevicular plaque from healthy sites. However, with plaque samples from diseased sites, the results of the PerioScan test showed very strong correlation with those obtained with the ELISA, suggesting that the former may be a useful, rapid means of indicating the presence of T. denticola and P. gingivalis in such plaque samples.