Detection of Tannerella forsythensis (Bacteroides forsythus) and Porphyromonas gingivalis by polymerase chain reaction in subjects with different periodontal status

Background: The aim of this study was to determine the prevalence of Tannerella forsythensis (formerly Bacteroides forsythus) and Porphyromonas gingivalis in subgingival plaque samples by using polymerase chain reaction (PCR), and to assess the relationship of these bacteria with different categories of periodontal disease and health. Methods: Subjects were distributed into 3 groups according to their periodontal diagnosis: group 1, periodontally healthy (N = 10); group 2, periodontitis with probing depth less than or equal to5 mm (N = 10); group 3, periodontitis with probing depth >5 mm (N = 10). The subjects in groups 2 and 3 had healthy and diseased periodontal sites. Subgingival plaque samples were obtained using paper points inserted into periodontal pockets (diseased sites) and into healthy gingival sulci (healthy sites) of the same subject. Results: The distribution of bacteria differed in healthy and diseased sites. T forsythensis (B. forsythus) was not detected in any sample from healthy sites in any group but was detected in 70% and 100% of diseased sites in groups 2 and 3, respectively. P. gingivalis was detected in only one sample from a healthy site (group 2), and in the diseased sites, its prevalence was 40% (group 2) and 90% (group 3). In addition, T forsythensis (B. forsythus) and P gingivalis were both detected in 30% and 90% of the diseased sites in groups 2 and 3, respectively. Conclusion: These results indicate a possible association between periodontal disease and the presence of T forsythensis (B. forsythus) and/or P gingivalis.