Bacteria are the main cause of periodontitis

The bacteria chiefly responsible for the development and progression of periodontitis are mainly anaerobic, Gram-negative species. These interact closely with each other and occur characteristically in different disease phases.

Composition of the oral flora

The healthy periodontium is colonized predominantly with aerobic, Gram-positive “beneficial” bacteria. These form part of the normal local flora and help to maintain stable oral conditions. Anaerobic/facultatively anaerobic, Gram-negative periodontopathogenic bacteria are present even in individuals with a healthy periodontium, however, albeit in smaller numbers. These marker bacteria become a problem when their concentrations spiral upwards because of poor oral hygiene or declining immune competence.

In the course of periodontitis gingival pockets are getting deeper and the jawbone is broken down.

In healthy individuals, the oral flora is dominated by harmless bacteria. The development and progression of periodontitis is associated with a shift in the microbial composition towards periodontopathogenic bacteria. There is an increase in the concentration of these bacteria.

The pioneering work carried out by Sigmund Socransky et al. shows that the pathogenesis of periodontitis is associated with a specific group of bacteria. These are classified into various “complexes” of bacteria that are physiologically closely interrelated. The individual complexes differ in terms of their pathogenicity and may make adjunctive antibiotic use necessary.

Development of periodontitis

The colonization of the sulcus with periodontopathogenic bacteria takes place in distinct phases, each characterized by the appearance of certain species and associated symptoms. After initial colonization with moderately pathogenic organisms, an aggressive inflammatory process develops in which the clinical presentation is determined by highly pathogenic species. It is worth noting that periodontitis is a typical infectious disease and the bacteria can be spread to people close to the patient.