Figure 5.
Bars charts (± standard error of the mean) of the mean counts (×105) of 40 taxa in subgingival biofilm samples taken from 292 subjects with periodontitis subset according to two severity categories (“the least” severe and “the most” severe) in different age groups (<35, 35–64 and >64 years old). Nine subgingival biofilm samples were taken from each subject and were analyzed separately to determine their content of 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. The significance of differences between severity category in each age group was determined using analysis of covariance (ANCOVA), adjusted for smoking, gender and geographic population.