Oral Soft Tissue Microbiotas in Healthy, Periodontitis and Edentulous Subjects

Objectives: To compare the oral soft tissue microbiotas in periodontally healthy, chronic periodontitis and fully edentulous, denture-wearing subjects. Methods: Soft tissue samples were taken from 8 soft tissue surfaces in 30 periodontally healthy, 8 periodontitis and 18 edentulous subjects: tongue dorsum (TD), lateral (TL) ventral (TV), floor of mouth (FOM), buccal (B), hard palate (HP), vestibule/lip (VL) and attached gingiva (AG) using a buccal brush as well as un-stimulated saliva (S) at baseline and individually analyzed for their content of 41 bacterial species using checkerboard DNA-DNA hybridization. Levels and % DNA probe counts of each species were determined for each sampled site and averaged across subjects for each sample location in each clinical group separately. Significance of difference for each species between clinical groups at each sample location was determined using the Kruskal Wallis test. Results: In general, the mean microbial profiles at the different sample locations were more similar between the heathy and periodontitis subjects than the edentulous subjects. For example, proportions of F. nucleatum subspecies, E corrodens and V. parvula were significantly lower for most sample locations in the edentulous subjects. In contrast, proportions of S. mitis and S. gordonii were significantly higher at all soft tissue sites, except TD and TL in the edentulous subjects. F. periodonticum was also detected in high proportions in the edentulous subjects. Total DNA probe counts were higher on the soft tissues of edentulous subjects. Conclusions: The oral soft tissue microbiotas of edentulous subjects differed markedly from those of healthy or periodontitis subjects. Supported by NIDCR grant DE14368.