Figure 2.

Established periodontal disease is an important source of pathogenic bacteria that can influence the onset and development of lung infection. Periodontal bacteria can disseminate into the lower respiratory system as a consequence of saliva or food aspiration, especially in older individuals, but also inoculation during endotracheal intubation. P. gingivalis is a prominent Gram-negative pathogen implicated in the development of periodontal disease, with highest prevalence in elderly people.