ASSOCIATION OF ORAL SPIROCHETES FROM PERIODONTALLY HEALTHY SITES WITHDEVELOPMENT OF GINGIVITIS

THE PURPOSE OF THIS INVESTIGATION was to determine whether the presenc e of selected disease-associated bacteria in health-associated plaque correlated with future gingivitis. Sites of periodontal health were id entified in 65 adults. Six months later (recall 1) plaque was collecte d from sites that remained in periodontal health, and 5 species of spe cific bacteria and pathogen-related oral spirochetes were detected usi ng monoclonal antibodies in a microscopic assay. Members of the spiroc hete morphogroup were also identified by phase contrast microscopy. Th e relationship between site-specific detection of bacteria at recall 1 and development of gingivitis at recall 2 or 3 was evaluated by means of logistic regression using generalized estimating equations, from w hich odds ratios (OR) were estimated. Significance was conservatively defined as OR > 2.0 and P < 0.05. We found that 488 of 1,424 healthy s ites developed gingivitis over the 12-month interval between recall 1 and 3. Only the spirochete morphogroup (OR = 2.04; P = 0.002) was sign ificantly associated with the transition from health to gingivitis. Th e association of Treponema socranskii with future gingivitis was highe r than expected (OR = 2.27), but the relationship was not statisticall y significant (P = 0.163). Campylobacter rectus, Eikenella corrodens, Porphyromonas gingivalis, and pathogen-related oral spirochetes did no t correlate well with gingivitis (OR < 2.0). Health-associated plaque from 5 sites contained Treponema denticola, and all 5 sites progressed to gingivitis. An OR could not be calculated because T. denticola was not detected in health-associated plaque from stable healthy sites. T hese findings indicated that the presence of T. denticola and unidenti fied spirochetes in health-associated plaque was associated with incre ased susceptibility to gingival inflammation. Future studies assessing a larger panel of dental plaque microorganisms, with shorter interval s between baseline and follow-up assessment, are necessary to more ful ly evaluate the association between detection of specific organisms at healthy sites and risk for gingivitis.