Tuesday, November 9, 2010: 9:42 AM
151 D/E Room (Salt Palace Convention Center)
Acidogenic biofilms are well-known to be efficient colonizers of surfaces which can have devastating effects from corrosion of ships hulls to bone loss, which, in either case, leads to significant structural damage of materials that are relied upon for day to day use. In this study, we take novel multi-scale multimodal approach to gain a deeper insight into acid-producing biofilm behavior, using Streptococcus mutans as a model. S. mutans is a well studied dental pathogen and the primary etiologic agent of dental caries. The capacity of S. mutans biofilms to exert pathogenic effects are due to its ability to rapidly secrete extra-polymeric substances (EPS), and lower the local and surrounding pH, which both inhibits the growth of other biofilms and etches a protective niche in the hydroxyapatite surface of a tooth. Utilizing sucrose-dependent protein pathways, glucosyltransferases produce copious amounts of adhesive polymers (alpha 1-3 and alpha 1-6 glucans), which facilitate the formation of a rigid, immobilized biofilm. Sucrose is then converted into lactic acid, which then demineralizes and erodes the tooth surface. Although these events are generally known, the inability to temporally or spatially quantify the occurrence of biofilm-mediated damage to tooth surfaces with respect to the constantly changing properties of the causative biofilm has left many questions unanswered. Using a unique multimodal, multi-scale approach, fluorescently labeled S. mutans biofilms were evaluated for their pathogenic attributes in the presence and absence of sucrose using rheometry and high-resolution interferometric optical profilometry over time in clinically mimicked conditions. The results of this study not only provide critical insight into the mechanism of dental pathogenesis for S. mutans, but also provides an advanced means of evaluating the capacity of newly engineered dental polymers to protect the tooth surface. This experimental approach is designed to be a simple and rapid system for evaluation of the effects of surface-modifying acidogenic biofilms.