Periodontitis is a chronic inflammatory disease that invades the gum and periodontal tissues and is a destructive disease characterized by the formation of periodontal pockets, resorption of the alveolar bone and gradual loosening of the teeth. Periodontitis is characterized by chronic destruction of the tissues surrounding the teeth (including the gums, periodontium, and alveolar bone), and is often unnoticed by the general public because of the lack of obvious self-perceived symptoms. Initially, the symptoms are simply bleeding gums when brushing, and sometimes when talking or biting hard objects. Such symptoms can last for several years, but otherwise there is no discomfort, so they are often ignored by patients. As the disease progresses, the destruction of the alveolar bone supporting the teeth is gradually aggravated, and when the chronic destructive inflammation develops to a certain extent and the supporting force of periodontal tissue is greatly weakened, tooth loosening, chewing weakness, tooth displacement, abscess and pain will occur, which is what draws the attention of patients and brings them to the hospital. If left untreated, the number of teeth lost is often not a single tooth but a majority of teeth. It is the main cause of tooth loss in adults. Periodontitis not only causes loosening and loss of teeth, but also has a close relationship with general health. The presence of a large number of pathogenic bacteria at the site of periodontal inflammation, these bacteria can produce endotoxins and invade the bloodstream, causing changes in coagulation mechanisms and degeneration of platelets, as well as direct stimulation of blood vessels, leading to spasm of small arteries. If the coronary arteries are involved and contraction spasm occurs, together with the action of microscopic thrombi, it can cause the development of acute myocardial infarction. Periodontitis is a risk factor for atherosclerosis and acute myocardial infarction. Infective endocarditis is also associated with periodontitis. Many studies have confirmed the association of preterm and low birth weight infants with maternal periodontitis. Therefore, women of childbearing age with periodontitis should first treat periodontitis and control inflammation before preparing for pregnancy in order to ensure a healthy pregnancy and fetus. Diabetes and periodontitis are risk factors for each other. Poorly controlled blood sugar makes it difficult to ensure periodontal health; conversely, uncontrolled periodontal inflammation makes it difficult to achieve normal blood sugar levels. Periodontitis is also associated with digestive and respiratory diseases. The subgingival plaque of patients with periodontitis contains a large number of pathogenic bacteria, which may be a reservoir for Helicobacter pylori and respiratory pathogens.