Fig. 6

a SEM images of the implant surfaces of the positive controls with E. faecalis; top left and top right: 5000× magnification; bottom left and bottom right: 8000 × magnification. All untreated samples who served as control showed clear microbial growth on the sandblasted and acid-etched implant surface under the scanning electron microscope. The specific form of E. faecalis could also be identified. b SEM images of plasma-treated implant surfaces; top left and top right: 5000× magnification; bottom left and bottom right: 8000× magnification. A significantly reduced number of bacteria could be observed. c SEM images of phosphoric acid applied implant surfaces; top left and top right: 5000× magnification; bottom left and bottom right: 8000× magnification. Particularly a reduced number of bacteria could be observed. d SEM images of PDT applied implant surfaces; top left and top right: 5000× magnification; bottom left and bottom right: 8000× magnification. Despite reduced number of bacteria compared to the positive controls, large amounts of germs could be found