[Periodontitis - infection or inflammation?].

Periodontitis is a complex, multifactorial disease. Multiple factors such as (epi)genetic factors, environmental factors (microbial biofilm), lifestyle (smoking, stress) and general health (diabetes mellitus) contribute to the development of periodontitis. A healthy subgingival microbiome is in balance with its host, is very stable and diverse, and keeps the host healthy. Changes, such as declining oral hygiene, lead to changes in the microbial composition in the subgingival sulcus: anaerobic and protein-degrading microorganisms with pro-inflammatory properties increase in number and disturb the proportions, leading in turn to changes in the subgingival environment and an increase in pro-inflammatory microorganisms. If the first line of the immune system is unable to restore subgingival equilibrium, microorganisms and their products invade the periodontal soft tissues, resulting in activation of osteoclasts and, ultimately, in the destruction of the periodontium and the onset of periodontitis.