The overall aim with this study is to study aspects of periodontal disease in the adult population in Troms County (Norway) and identify and analyze demographics and risk factors as well as health promoting factors of importance for periodontal disease. The specific aims are to:

- Describe the sample characteristics and methods employed for the data collection procedure within the epidemiological survey (Paper I)

- Determine the prevalence, severity and extent of periodontitis in the adult population in the county of Troms, Norway. (Paper II)

- Assess the protective and the hazardous risk factors (BMI, smoking, oral hygiene, systemic diseases etc.) for the development of advanced periodontitis. (Paper III)