Immunological assays for putative periodontal pathogens

Immunological tests including immunofluorescence microscopy, latex agglutination, flow cytometry, and enzyme‐linked immunosorbent assays are being developed for the detection of carcinogenic microorganisms and periodontal pathogens. In the present study, indirect immunofluorescence microscopy was used to examine two hundred eighty‐three subjects for Actinobacillus (“Haemophilus”) actinomycetemcomitans and Bacteroides gingivalis in subgingival dental plaque samples pooled from the mesial surface of the four first molar teeth. Alveolar bone height on panoramic radiographs was measured at each sample site using a Schei ruler and correlated with the results of immunofluorescence microscopy. Over ninety percent of the subjects did not demonstrate either putative periodonlal pathogen or harbored only trace amounts. Only 5% of the subjects demonstrated 2% or greater A. actinomycclemcomitans and no subject harbored more than 5% consistent with the finding that there were no localized juvenile periodontitis patients in this subject group. Nine percent of the subjects revealed 2% or more, and 5% demonstrated 5% or more of the total cell count as B. gingivalis. K. gingivalis levels, however, did exhibit a significant positive correlation with loss of alveolar bone height. The use of immunofluorescence microscopy for B. gingivalis exhibited 19% sensitivity, 96% specificity, 69% positive predictive value, and 69% negative predictive value when correlated with alveolar bone height measurements. The present data indicate that indirect immunofluorescence microscopy is a useful, rapid method for the detection of A. actinomycetemcomitans and B. gingivalis in subgingival dental plaque which can be used in the clinical diagnosis, treatment, and monitoring of periodontal disease. The sensitivity of microbiological assays as indicators of periodontal disease can likely be increased by utilization of additional Immunological tests for other putative periodontal pathogens.