Outcome After Dental Implant Treatment

* A questionnaire study will investigate patient satisfaction 8-14 years after dental implant therapy to study if complications influence the degree of satisfaction/quality of life. The questionnaire will be sent to 587 patients treated at The Specialist Clinic Skanstull. * A clinical examination of a minimum 150 patients who answered the questionnaire will be performed: * to study the incidence of biological and technical complications on dental implants after a minimum of 10 year of function. * to study the survival rates of implants at patient level and the degree of bone loss of remaining teeth and implants. In addition, the correlation between bone loss of remaining teeth and bone loss of implants will be studied. * samples taken from the gingival crevicular fluid to investigate the profile of cytokines and bone resorption markers as well as to study the intra-individual correlation of cytokines and bone markers in gingival crevicular fluid from sites with peri-implantitis and periodontal defects in individuals with dental implants. * in addition, the salivary cytokine and bone resorption markers will be analyzed in order to identify disease-specific biomarkers as well as to study the correlation between the cytokine/bone resorption markers in saliva and in gingival/peri-implant crevicular fluid. * To identify significant risk factors or risk predictors on the incidence of peri-implantitis.