Microbiota of Tooth-Associated Biofilms in Sjogren's Subjects

Objectives: To compare the supra and subgingival microbiotas of Sjogren's subjects with those of periodontally healthy and periodontitis subjects. Methods: Separate supra and subgingival plaque samples were taken from the mesial aspect of each tooth at baseline in 24 Sjogren's, 30 periodontally healthy and 53 periodontitis subjects and individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. Levels and % DNA probe counts of each species were determined for each sampled site and averaged within each subject for supra and subgingival plaque samples separately. Significance of difference for each species among clinical groups was determined using the Kruskal-Wallis test and adjusted for multiple comparisons. Results: Mean (x 10⁵, +SEM) total DNA probe counts in Sjogren's, health, and periodontitis were supragingivally 13.3±2.7, 44.1±6.8 and 43.2±3.5 (p<0.001) and subgingivally 11.4±1.3, 14.7±2.0 and 24.9±2.3 (p<0.001). In supragingival samples, mean counts of 30 species and proportions of 10 species differed significantly among groups after adjusting for multiple comparisons. In subgingival samples, mean counts of 19 species and proportions of 16 species differed significantly among groups. The supragingival microbiota of Sjogren's subjects was characterized by high proportions of V. parvula (mean % +SEM in Sjogren's, health and periodontitis were 17.2±2.0, 9.3±1.0, 10.2±0.7 p<0.05) and N. mucosa (13.8±2.2, 11.0±1.7 and 4.1±0.7, p< 0.001). The subgingival microbiota of Sjogren's exhibited low counts of most species compared with periodontitis and healthy subjects. T. forsythia, P. gingivalis, T. denticola and T. socranskii were markedly higher in periodontitis than healthy or Sjogren's subjects. Conclusions: There were many significant differences in the supra and subgingival microbial composition of H, P and S subjects. Differences in mean total DNA probe counts and microbial profiles among the 3 clinical groups for subgingival plaque were not the same as those observed for supragingival plaque. Supported by NIDCR grant DE14368.