Bacterial plaque (dental plaque, biofilm) is the major cause of gum inflammation (gingivitis). Some bacteria can further promote the development of periodontitis.
Gingivitis and periodontitis are caused by bacteria that build up on the surface of teeth. This coating is also called dental plaque or biofilm. When oral hygiene is inadequate, bacteria can multiply quickly. While most kinds of bacteria are harmless for a healthy person, some kinds – even in small numbers – can cause serious infections.
If bacterial plaque is not removed from the teeth regularly, the gum reacts with an inflammation after just a few days. The gum becomes red, swollen, and bleeds at the slightest stimulation, for example when using dental floss. However, when the teeth are cleaned with regular oral hygiene at home, these signs of inflammation go away within a few days.