Saliva-Promoted Adhesion of <i>Streptococcus mutans</i> MT8148 Associates with Dental Plaque and Caries Experience

Abstract

Colonization of enamel surfaces by <i>Streptococcus mutans</i> is thought to be initiated by the attachment of bacteria to a saliva-derived conditioning film (acquired pellicle). However, the clinical relevance of the contribution of saliva-promoted <i>S. mutans</i> adhesion in biofilm formation has not yet been fully elucidated. The aim of this study was to correlate saliva-promoted <i>S. mutans</i> adhesion with biofilm formation in humans. We correlated all measurements of salivary factors and dental plaque formation in 70 healthy subjects. Dental plaque development after thorough professional teeth cleaning correlated positively with <i>S. mutans</i> adhesion onto saliva-coated hydroxyapatite pellets and the glycoprotein content of either parotid or whole saliva. Saliva-promoted <i>S. mutans</i> adhesion and glycoprotein content were also positively correlated with each other in parotid and whole saliva. By contrast, neither salivary mutans streptococci, <i>Lactobacillus</i> nor <i>Candida</i> correlated with biofilm formation. Parotid saliva-mediated <i>S. mutans</i> adhesion was significantly higher in 12 caries-experienced (CE) subjects than in 9 caries-inexperienced (CI) subjects. Salivary <i>S. mutans</i> adhesion was significantly less (p < 0.01) in the CI group than in the CE group. In conclusion, the present findings suggest the initial <i>S. mutans</i> adhesion, modulated by salivary protein adsorption onto the enamel surface, as a possible correlate of susceptibility to dental plaque and caries.