Periodontitis in Young Individuals, Follow up of Treatment and Disease Progression Over 10 Years

The general aim of this project is to get a better understanding how periodontitis develop in young individuals over time and identify factors that contribute to disease recurrence. The investigators also want to see if Stage and Grade of the periodontal disease has a significant impact on disease progression. In addition, another purpose is to identify factors explaining why certain young patients with periodontitis interrupt the periodontal treatment. The specific aims of the project are: * To study the periodontal status and the degree of disease progression over 10 years for young individuals with periodontitis at age \< 36 yrs at baseline (study 1) * To identify factors with a significant influence on periodontitis progression for young individuals with periodontitis at baseline (study 2) * To identify explanatory factors to discontinuation of periodontal treatment (study 3) * To identify bio marker and microbiological profiles in young individuals in relation to stage and grade of periodontitis (study 4) Significance: A high patient compliance rate and effective supportive treatment to prevent periodontitis progression are crucial conditions for the long-term prognosis. The identification of factors influencing the compliance rate can improve the frequency of individuals following a supportive care program. In addition, long-time follow-up studies of individuals with the diagnosis severe periodontitis at young age are lacking as well as deeper knowledge concerning risk predictors for further disease progression. The identification of biomarkers or microorganisms that can differentiate between different stage and grade of periodontitis could make it possible to identify individuals with a high risk for disease progression at an early stage.