No disease stands alone. Periodontal disease and caries are diseases with a very high incidence. And periodontal disease is the main cause of tooth loss in adults. The relationship between periodontal disease and systemic diseases has been a hot topic of research. The relationship between periodontal disease and systemic diseases has always been a hot topic of research. Currently, it is clear that periodontal disease and diabetes mellitus have mutual influence on glycemic control, and even cause each other, and the relationship between periodontal disease and the cardiovascular system has been found to be caused by periodontopathogenic bacteria in atherosclerotic plaques, and clinical studies have shown that the two have mutual influence on each other. The relationship between periodontal disease and the cardiovascular system has been studied in atherosclerotic plaques, and clinical studies have repeatedly shown the interaction between the two. More recently, periodontopathogenic bacteria have been found in the amniotic fluid of fetuses born prematurely to mothers with periodontal disease. Among the relationships between periodontitis and systemic diseases, diabetes mellitus is the most closely linked and well-studied. Poor glycemic control in diabetic patients sometimes induces multiple periodontal abscesses, which are very painful for the patient. When the periodontal situation improves, the corresponding blood sugar is much smoother. Another thing to add is that usually diabetic patients with concomitant periodontitis are more severe, so scaling alone is not enough because severe periodontitis is mainly about eliminating deep periodontal pockets and controlling the progression of periodontitis. Therefore deep scaling and root planing are essential. For some of the teeth that need to be retained and are in poor condition periodontal surgery is also required – flap surgery bone revision bone grafting etc.