Factors affecting supragingival biofilm composition. II. Tooth position

Objectives: To compare the effect of tooth type/location on supragingival biofilm mass, composition and adjacent periodontal status. Methods: Supragingival plaque samples were taken from the mesiobuccal of each tooth in 187 subjects at baseline (N samples = 4,745; mean per subject=25.4). All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. Significance of differences in mean species counts and proportions were determined among tooth surfaces and 6 tooth type categories: molars, bicuspids, incisors/canines separately in the mandible and maxilla using the Kruskal Wallis test. Relationships between mean plaque mass and mean clinical parameters at different tooth categories was determined using regression analysis.

Results: All 40 test species differed significantly among tooth types and among the 6 tooth categories. Higher plaque levels were seen at molars and lower incisors. Some differences observed between tooth types could be partially explained by the level of plaque. Teeth with high plaque mass exhibited high levels of Capnocytophaga gingivalis, Actinomyces naeslundii genospecies 2, Campylobacter rectus and Campylobacter showae. However, certain species such as Veillonella parvula and Streptococcus sanguinis differed significantly at different tooth locations despite similarities in plaque mass. Mean total DNA probe counts related to the mean percentage of sites with visible plaque (r=0.99, p<0.001) or mean gingival redness (r=0.84, p<0.05), but did not significantly relate to mean % of sites with bleeding on probing, mean pocket depth and mean attachment level for the different tooth type categories. Conclusions: The microbial composition and levels of supragingival biofilm differed among tooth types and categories. Some, but not all, of these differences related to total plaque mass. Supported by DE12108 and DE14368.