The capability of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius to indicate progressive periodontitis; a retrospective study.

This study evaluated the statistical association of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius with progressive periodontitis. 146 adults with a history of advanced periodontitis contributed 105 "nonprogressing" and 130 "progressing" periodontal sites. Periodontal disease activity was assessed by radiographic changes in crestal alveolar bone level. The subgingival proportion of the 3 test bacteria was determined by selective and nonselective culturing. The relationship between bacterial proportions and disease progression was evaluated using subgrouping and multiple-regression analyses. All 3 test bacteria had to be considered in order to distinguish nonprogressing and progressing periodontitis with a reasonably high sensitivity. A recovery rate below 0.01% for A. actinomycetemcomitans, 0.1% for B. gingivalis and 2.5% for B. intermedius defined a site with nonprogressing disease with 87% sensitivity and 84% specificity. By utilizing transformed values of the bacterial recovery rates and optimal test criteria determined by multiple regression analysis, it was possible to obtain sensitivities between 83% and 95% and specificities between 86% and 69%. These 3 bacterial species might serve as valuable components of a periodontitis activity test based on microbiological variables.