If there has been any oral disease (e.g. bleeding from the heel of the tooth when brushing, tooth remnants or fillings, tooth sensitivity to temperature, swollen gums, root abscesses, loose teeth, etc.), the chemotherapy doctor and nurse should be informed promptly and they can refer the patient to a dental specialist if necessary. If possible, it is best to visit a specialist dentist 2 weeks before starting chemotherapy. Clearly inform the dentist of the current disease status, the chemotherapy drugs to be received and the dosing regimen so that the dentist can provide appropriate dental care measures for the current chemotherapy regimen. Use a soft-bristled toothbrush and a regular fluoride toothpaste, preferably a gel toothpaste, not a strong tartar remover or a high friction formula. Brush your teeth after every meal and before going to bed, and brush gently. After brushing, you can rinse your mouth with water or a small amount of mouthwash formulated with sodium bicarbonate. Try to avoid commercially available strongly formulated mouthwashes, as most of these products contain alcohol, which may damage the oral mucosa. If occasionally you are unable to brush your teeth after eating, you can rinse your mouth with water. If you are in the habit of flossing for a long time, you can use waxed floss to floss your teeth. If you have not flossed before, you should consult with a specialist before deciding to floss. Before flossing, make sure that coagulation is normal. If platelets are low and you are in the habit of flossing, you must be careful to grasp the floss and avoid touching the gums. If dentures are worn, they should be removed and worn very carefully during chemotherapy. If the dentures do not fit well, try to avoid wearing them because they may damage the gum tissue during chemotherapy, which can lead to interruption of chemotherapy in severe cases. Soak your dentures in a denture care solution before bedtime. On the day of chemotherapy, try not to wear dentures because they may exacerbate chemotherapy-induced nausea and vomiting. If chemotherapy has caused abnormal blood cells, dentures should not be worn.