Choose the right method of brushing, brush at least 2 times a day, and develop the habit of gargle after eating. It is also very important to carry out tongue cleaning. Since 80% to 90% of bad breath comes from the back of the tongue, the dentist should teach the patient to use the tongue curette correctly to clean the tongue. The commonly used mouthwashes include chlorhexidine, chlorine-containing compounds, hydrogen peroxide, sodium salts, zinc salts, etc. Good mouthwashes should achieve an ecological balance that maintains the normal flora of the oral cavity and prevents new diseases caused by dysbacteriosis. . Stimulate saliva secretion or use substitutes. Because saliva has antibacterial, bactericidal, and cleansing effects on the mouth, it is also advisable to increase the amount and flow rate of saliva, enhance the movement of the tongue, chew fiber-rich foods or chew gum. Reduce bad breath