Many people think that it is a natural law that people lose their teeth when they get old, but this is actually a wrong viewpoint, teeth can be with people throughout their lives, the World Health Organization set the standard that 80-year-olds should have 20 teeth. Why does the phenomenon of “old tooth loss” occur? This is because periodontal disease is not treated in a timely manner. Periodontal disease is the damage to the tissues that support the stability of teeth (gums, periodontal membrane, alveolar bone) and cannot hold the teeth tightly, resulting in bleeding gums, overflowing pus, loosening and shifting of teeth, and eventually leading to tooth loss. Without timely and effective treatment, the number of teeth lost is often multiple teeth or even the whole mouth. It is the leading cause of tooth loss in adults. Periodontal disease is treatable. It is mainly divided into gingivitis and periodontitis. Gingivitis can be fully recovered after thorough periodontal treatment. If the disease is not controlled at this stage, it will develop into periodontitis, producing resorption of the alveolar bone and receding gums, gradually followed by loosening and displacement of the teeth. Therefore, it is important to emphasize that active treatment should be carried out as early as possible, because the early stages of treatment are very effective.