Periodontal disease is not only the primary cause of tooth loss in adults, but is also an important cause of various diseases with extremely high mortality rates by affecting the function of important organs such as the heart, lungs and kidneys. Predisposing to cardiovascular disease, the enzymes produced by periodontal bacteria can contribute to the formation of blood clots in the body. Periodontal bacteria enter the bloodstream and prompt the body to produce a gelatinous protein that acts similar to platelets, forming clots that block blood vessels and lead to heart disease and stroke. It has been reported that patients with periodontitis are 1.4 times more likely to have coronary heart disease and 2.1 times more likely to have a stroke than those with normal periodontal disease. Pneumonia is easily caused, and pneumonia suffered by the elderly is closely related to periodontal disease. A large number of bacteria in the mouth can be inhaled into the lungs, leading to pneumonia. People with poor oral hygiene are prone to periodontal disease and are twice as likely to have chronic lung infections and reduced lung function than those with good oral hygiene. It affects the fetus, and 2/3 of the stillborn babies in developed countries are caused by premature birth. Pregnant women with severe periodontitis are 7.5 times more likely to have preterm births and low birth weight babies than those with normal periodontal disease. The University of North Carolina investigated the relationship between preterm infants and their mothers’ oral disease and found that in some preterm infants there were antibodies corresponding to the presence of bacteria in their mothers’ mouths, confirming that these preterm infants were associated with their mothers’ periodontal disease. Helicobacter pylori is the causative agent of chronic gastritis, gastric ulcers and even gastric cancer. In recent years, researchers have detected H. pylori in dental plaque and saliva, and the detection rate of H. pylori in plaque is higher in patients with periodontal disease than in those with healthy periodontium. In addition, periodontal disease, as a focus of infection, can cause a variety of inflammatory conditions, such as rheumatic or rheumatoid arthritis, glomerulonephritis, iridocyclitis, and certain skin conditions. The presence of periodontal disease must be treated in a timely manner without delay.