People with diabetes are more likely to develop periodontal disease. Periodontal disease is the sixth major complication of diabetes. A survey in Tianjin pointed out that about half of diabetic patients have periodontal disease in combination. Foreign studies illustrate that the incidence of combined periodontal disease is three times higher in diabetic patients than in non-diabetic patients. So, why are diabetic patients prone to periodontal disease? Diabetic patients not only have elevated blood sugar, but also elevated glucose concentration in saliva and gingival sulcus, which will inhibit the function of white blood cells and reduce immunity, plus diabetic patients often have reduced saliva secretion, which will be less effective in cleaning debris in the mouth. These tend to cause pathogenic bacteria to multiply. Periodontal disease starts from the accumulated food debris left between the teeth and gums, which contains bacteria that constantly invade the gums, causing inflammation and destroying its tissues internally. In addition, the diabetic patient’s own tissue repair ability is reduced, it is easy to occur periodontal disease and difficult to repair. For example, the content of some oral cavity enzymes that can remove bacteria decreases in diabetes, and the collagen content of tissues decreases. 17 years ago, the Department of Dentistry of our hospital, in cooperation with us, examined the oral cavity of hundreds of patients and found that the opening of the parotid gland of the patients was swollen and the secretion of the gland was significantly reduced. Therefore, many diabetic patients feel dry mouth. With less saliva, the ability to remove impurities from the mouth is reduced. The combined microangiopathy of diabetes can cause ischemia and hypoxia in the gum tissue, which likewise affects the ability of the patient’s teeth to repair. Diabetic patients have a higher chance of developing periodontal disease, and some patients’ gums tend to bleed when they brush their teeth. Bleeding gums are actually a sign of periodontal disease. Individual patients have pain or pressure in the teeth or all of the teeth, and the degree of periodontal disease is often severe, such as red, swollen, bleeding gums and tooth sores. Hyperglycemia makes it difficult to control infection in the mouth, and periodontitis is further aggravated with loss of periodontal bone, loose teeth and missing teeth. Some young and middle-aged patients develop loose teeth and missing teeth, and these often suggest that the patient may have diabetes. Missing teeth impair chewing function, and patients with severe tooth loss often have difficulty chewing adequately during meals. Chewing is both the process of cutting food and the process of mixing saliva filled with digestive enzymes with the food. Without adequate chewing of food into the gastrointestinal tract, not only is not conducive to digestion, but also may bring too much bacteria, and even affect the function of the digestive tract mouth is the gateway to the digestive tract, periodontal or “hide dirt and grime” place. It is a famous saying that disease enters through the mouth. The function of teeth is not only to cut food, but also a sign of health. One of the World Health Organization’s definitions of health is to have good teeth. However, in reality, there is a lack of awareness about dental care, diabetes specialists and patients about periodontal disease. I often see such diabetic patients in my practice, who have lost their teeth in their 30s and give me the impression of a very senile image when they visit me. This also reminds us that if you tend to get food stuck in your teeth when you eat, if you brush your teeth because your gums bleed easily, if you have early loosening of teeth, then you probably have diabetes; if you are already diabetic, then these dental manifestations suggest that your hyperglycemia is often not well controlled. Conversely, when we encounter a patient with persistent hyperglycemia or a recent rise in blood sugar that is difficult to control, it is important to check the patient for periodontal disease and complications of periodontal infection. In addition to daily oral cleaning, diabetic patients should visit the dentist every three to four months for dental checkups and preferably 1-2 dental cleanings a year. There are other methods of dental care, such as scientific brushing and tooth percussion. It is recommended that patients can consult a dentist.