Figure 1.

The evolution from a healthy periodontium to periodontitis. (a) Healthy tooth with no inflammation and a small gingival crevice (space between the tooth surface and the free gingiva). (b) A change in oral microbiota leads to increased bacteria biofilm deposition in the gingival crevice and produces moderate inflammation (gingivitis). (c) In severe cases, a chronic inflammatory state known as periodontitis is established, resulting in the formation of periodontal pockets (pathologically deepened gingival crevices) with extensive tissue destruction including bone loss.