The correct use of mouthwash is to take a mouthful of mouthwash, do oral cheek drum rinse action, so that mouthwash in the mouth can fully contact with teeth and gums, and use the water force to repeatedly rinse all parts of the mouth, as far as possible to remove the food residues left in the mouth. If the mouthwash is used correctly can remove food residue and some soft scale in the mouth, but it can not completely remove calculus, plaque and soft scale on the teeth, so it can not replace brushing. There are more types of mouthwash, which can be light salt water, tea, plain water, etc., or mouthwash with added ingredients such as fluoride. When using a mouthwash solution with special ingredients added, it should be used according to the type of mouthwash recommended by the doctor and in strict accordance with the instructions. If the patient is allergic, before using mouthwash, need to ask the doctor whether the mouthwash contains ingredients that cause their allergies, to avoid allergies and other uncomfortable symptoms in the organism. Some of the mouthwash needs to be diluted before use, should be under the guidance of a doctor, or according to the instructions on the proportion of dilution, some mouthwash after use, need to use cold boiled water to clean the mouth. For drug-containing mouthwash is not recommended for long-term use, such as mouthwash containing detergent peptides, which may break the balance of bacteria in the mouth.