Figure 3.
Profiles of the mean counts (×105) of 40 taxa in subgingival biofilm samples taken from 1084 subjects with periodontitis (Perio) and 246 periodontally healthy subjects subset into three age groups (<35, 35–64 and >64 years of old). Nine subgingival biofilm samples were taken from each subject and were analyzed separately to determine their content of the 40 species of bacteria. The species were ordered and grouped according to the microbial complexes described by Socransky et al. [89]. The mean values for each species were averaged within a subject and then across subjects in the two clinical groups for each age category. The significance of differences between clinical groups was determined using analysis of covariance (ANCOVA), adjusted for smoking, gender, baseline probing depth and clinical attachment level and geographic population.