Each day, most of us brush their teeth and/or rinse their mouth with oral hygiene products that
contain substances that kill bacteria (antiseptics). Unfortunately, often manual plaque removal by
means of a toothbrush or interdental cleaning devices is not perfect. Consequently, dental plaque, a
poly-microbial biofilm is left behind. It is well known that the used antiseptics will only kill the
bacteria in the upper layers of these biofilms. The impact of these dead bacteria on the survivors is
unknown. Preliminary evidence shows that certain surviving pathogenic bacteria can use these
remaining dead bacteria as a food source. Thereby, they can have nutritional advantages resulting in
an increased growth or pathogenicity. This project aims to investigate the effect of these dead
bacteria on the outgrowth and increased virulence of pathogens in dental plaque. By using different
models with increasing complexity, clinical reality, a mechanistic model will be demonstrated as
close as possible. Finally, a proof of principle will be given in a clinical study. This project might show
that care should be given to prevent the indiscriminate use of antiseptic containing toothpastes and
mouth rinses, since they might increase the pathogenicity of unremoved dental plaque.