Scanning Electron Micrograph (SEM) of 24 hours old biofilms.

(a) S. oralis, (b) A. naeslundii, (c) V. dispar, (d) P. gingivalis and (e) a four-species biofilm. In the mixed community, the individual species are exemplarily highlighted by arrows: S. oralis (a), A. naeslundii (b), V. dispar (c), and P. gingivalis (d).