Coloured scanning electron micrograph (SEM) of a subgingival biofilm from an inflamed periodontal pocket sampled by a paper point. It is densely packed with different species of bacteria (cyan, purple, blue, green, red). Periodontal pockets are spaces that form between the tooth and gum in cases of periodontitis (gum disease). The picture was created as part of a cooperation with Quintessenz Publishing. Magnification: x3,000 when printed at 15cm wide.