Why do old people not necessarily lose their teeth?

The real cause of tooth loss in the elderly is periodontal disease, which is one of the most serious chronic diseases that endanger people's health. Plaque and tartar are two "killers" of periodontal tissue diseases. Plaque can be removed by self-care methods (such as brushing and flossing), while tartar must be removed by washing teeth. It is unscientific to say that people must lose their teeth when they are old.