Effects of Surface Roughness and Free Energy on Oral Bacterial Adhesion

The oral cavity offers two interesting particularities which allow the evaluation of bacterial adhesion under a variety of conditions. From an ecological view point the oropharynx is considered an “open growth system” with an uninterrupted ingestion and removal of microorganisms and their nutrients. In order to colonize the oral cavity, bacteria must tackle the host defense mechanisms (including continuous shedding of mucosal membranes) and a variety of removal forces (e.g., friction by food intake, tongue and oral hygiene implements as well as the wash-out effect of the salivary and crevicular fluid outflow) (Fig. 1). Adherence to a surface is thus a key element for the colonization of the human oral cavity by the more than 500 bacterial taxa recorded from human oral samples which may cause inflammatory processes (e.g., gingivitis and periodontitis) (Fig. 1).