Bacterial adhesion forces and biofilm prevention on orthodontic materials

Bacterial adhesion and biofilm formation cause a variety of serious problems during orthodontic treatment, such as enamel demineralization and soft tissue inflammation. Understanding bacterial adhesion forces to orthodontic materials is an important challenge in both clinical and fundamental orthodontics and allows for the development of preventive measures. The thesis investigated the adhesion forces of oral bacterial strains to orthodontic materials using atomic force microscopy (AFM). This thesis found that the adhesives exert the strongest bacterial adhesion forces; and bacterial adhesion forces increase with increasing adhesion time and increasing surface roughness of orthodontic adhesives; non-specific adhesion force is repulsive on nonconductive surface and attractive on conductive surface, while hydrogen bonding force is always attractive and responsible for bacterial bond strengthening on orthodontic materials; quaternary ammonium can be effectively incorporated into composite for orthodontic biofilm prevention in vitro.