Tooth decay, also called cavity, is not really caused by bugs in the mouth or teeth, but by bacterial infection, and the common bacteria include Lactobacillus, Streptococcus mutans, etc. Caries is usually a disease that leads to the long-term unclean state inside the mouth under the influence of multiple factors mainly of bacterial invasion, and the teeth are gradually subjected to chronic progressive destruction, and the caries-causing factors include the environment in which the teeth are located, bad eating habits and the patient’s own factors, etc.: 1. The environment in which the teeth are located: under normal circumstances, the mouth is the only channel for human body to eat, and various kinds of food and air may produce A variety of bacteria, and a variety of bacteria can be in a balanced state. But when the brush is not clean and the oral environment is too poor, it will lead to the long-term existence or sudden proliferation of bacteria, and adhere to the tooth surface, causing caries; 2, bad diet: such as love to eat sweet food, love to drink drinks with high sugar content, if there is sugar residue in the mouth too high and too long, these bacteria can decompose the sugar to cause tooth damage, causing caries; 3, the patient’s own factors: such as the patient’s teeth are not The risk and probability of caries occurrence will be increased by factors such as the patient’s teeth are not neat, the antibacterial effect of saliva in the mouth is weak, the saliva secretion is insufficient, and the own resistance is weak. In addition, the occurrence of dental caries is a long-term and slow process, it is suggested that patients should pay attention to ensure oral hygiene, brush teeth in the morning and evening, rinse mouth in time after eating sweet food, and avoid smoking and alcohol as much as possible to prevent the occurrence of caries or avoid the aggravation of caries.