Fig. 3.

Mean counts (×10⁵) of 41 bacterial species in supragingival samples taken from 38 periodontally healthy and 17 subjects with periodontitis prior to professional removal of the dental biofilms, immediately after cleaning, and after 1, 2, 4 and 7 days of biofilm re-development. The subjects refrained from oral hygiene procedures for the 7 day test period. Supragingival biofilm samples were removed from the mesio-buccal aspect of all teeth (excluding third molars) pre-cleaning and immediately post-cleaning. Supragingival samples were also obtained from up to 7 teeth in randomly selected quadrants at 1, 2, 4 and 7 days after tooth cleaning. All samples were individually analyzed for their content of 41 taxa using checkerboard DNA-DNA hybridization. For analysis, species counts in the samples were averaged within each subject at each time point and then averaged across subjects in the 2 clinical groups. Significance of differences in mean species counts between groups at each time point was determined using the Mann Whitney test; * p < 0.05, ** p < 0.01, *** p < 0.001. The species were ordered according to previously described microbial complexes (Socransky et al. 1998).