In this thesis, the prevalence of risk factors is explored among patients with periodontitis, with a particular focus on diabetes, smoking status, and family history of periodontitis. With as additional aim to shed light on the association between diabetes and tooth loss, and provide recommendations to prevent this from occurring. The findings challenge the commonly held belief that periodontitis and diabetes are strongly linked. Through an evaluation of over 5000 referred periodontitis patients in the Netherlands, it was found that the percentage of patients with diabetes was relatively low compared to national prevalence rate. While a systematic review of the literature suggested a higher prevalence and chance of diabetes in patients with periodontitis. However, the included studies with a high prevalence were primarily conducted in Asia. In Europe, the diabetes prevalence among patients with periodontitis was approximately 4.3%, which supports doubts about the presumed connection. The results do suggest that diabetic patients face a slightly higher risk of tooth loss and edentulousness compared to those without diabetes. Therefore, it is recommended that oral health care providers give special attention to patients with diabetes to prevent tooth decay and gum disease. Furthermore, the results indicates that smokers and individuals with a family history of periodontitis should also receive extra attention from their oral health care provider, as these factors are significantly associated with a higher rate of periodontitis. Overall, the thesis offers important insights into the risk factors associated with periodontitis and provides valuable recommendations for preventing tooth loss and promoting good oral health.