Comparison of DNA probe and ELISA microbial analysis methods and their association with adult periodontitis

The purposes of this study were two-fold: to compare the DNA probe and enzyme linked immunosorbent assay (ELISA) microbial identification tests and correlate the levels of microorganisms with adult periodontitis. A single plaque sample were taken from each of 2 sites in 52 patients. Twelve of these patients were also sampled during and after treatment. The experimental site had clinical indicators of disease (bleeding on probing, probing and attachment loss of > or = 6 mm) and the contralateral site (control) was clinically healthy. A total of 176 plaque samples were collected, divided, processed, and sent for both types of quantitative microbial analyses. All of these samples were used to compare the DNA probe and ELISA methods while only the initial 104 pretreatment sites were used to correlate microorganisms/method with clinical indicators of adult periodontitis. DNA probes were used to assay for A. actinomycetemcomitans, P. gingivalis, P. intermedia, E. corrodens, F. nucleatum, T. denticola, and C. rectus. An ELISA utilizing monoclonal antibodies was used to assay for P. gingivalis, E. corrodens, T. denticola, and C. rectus. Comparison of the two methods revealed that the ELISA test identified P. gingivalis and C. rectus significantly more often than the DNA probe method and that T. denticola was detected more frequently with the DNA probe. The sensitivities and specificities varied widely among organisms and by test. P. gingivalis, as identified by ELISA, had the highest degree of sensitivity and specificity (0.90 and 0.82 respectively) to clinical indicators of adult periodontitis.