[Risk of periodontitis--etiology and assessment]

Highly pathogenic microbiota, mixed infections and opportunistic species are the major etiological factor in periodontal diseases, the progression is then modified by known or unknown host factors. Selection of periodontitis-risk individuals is in most cases difficult. Nevertheless epidemiologic data of 2263 subjects show clearly risk age groups (45-54 year and older) and risk teeth. Patients at risk age and risk teeth have to be followed up carefully. The individual risk for deep pocketing and/or attachment loss can be detected on the basis of bleeding after treatment, rapid attachment loss (greater than 1-2 mm/yr) and trends in colonization/recolonization of pathogenic subgingival flora.