ORAL MICROBIOTA IN SUBJECTS WITH A WEAK OR STRONG RESPONSE IN EXPERIMENTAL GINGIVITIS

The purpose of the present study was to examine the composition of the oral microbiota in subjects who had previously demonstrated to develo p either a weak or strong response to experimental gingivitis. For thi s study, subjects were selected from a pool of 25 individuals who had participated twice in an experimental gingivitis trial. Out of these 2 5 panellists, 6 subjects were selected who had developed 2x a weak gin gival inflammatory response and 7 subjects who had developed 2x a stro ng gingival inflammatory response. Approximately 9 months after the 2n d experimental gingivitis trial, we evaluated the clinical condition a nd the prevalence of a panel of selected oral micro-organisms in these subjects. The subjects were clinically examined for the presence of p laque, bleeding, pocket depth and loss of attachment. For the microbio logical evaluation, samples were taken from the mucous membranes, subg ingival sites and saliva. Samples were analyzed for the presence of Ac tinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotel la intermedia, Peptostreptococcus micros, Actinomyces spp., Fusobacter ium nucleatum, Campylobacter rectus, spirochaetes and motile rods. Cli nical evaluation showed that most subjects had a relatively healthy pe riodontal condition. No clinically significant differences could be de tected between the weak and strong responding groups. The microbial ev aluation showed absence of A. actinomycetemcomitans, P. gingivalis and P. micros in all subjects in either group. Analysis of the microbial data for the weak and strong responding group showed no differences be tween the groups. This indicates that differences in response to exper imental gingivitis are probably not caused by major differences in the compositon of the oral microbiota. The strong or weak inflammatory re sponse may be related to differences in the microflora at the time of the experiments and/or differences in host response.