Fig 2. Typical fluorescence images of biofilms after 48 hours.

P. gingivalis, S. gordonii or both species were inoculated for 15 min in a saliva-coated flow cell. After 48 hours, bacteria were stained with 5 μM of Syto40 and flow cells were observed by confocal laser scanning microscopy. Images of optical stacks were processed using IMAGEJ software. Images of one representative experiment for each type of biofilm are shown, with the maximum 3D z projection of acquired stacks and the 2-D x-z or y-z planes slices.