Try not to smoke after tooth extraction because the nicotine in the cigarette can affect the healing of the wound. Nicotine will prolong the healing of the extraction wound, so patients are advised not to smoke as much as possible after tooth extraction, and should strictly follow the precautions after tooth extraction. The precautions after tooth extraction include the following: 1. you can spit out the cotton ball in your mouth after half an hour after tooth extraction, do not suck after spitting, and then spit again in the office, that will easily dislodge the clot in the extraction socket and cause bleeding. 2. you cannot brush and rinse your mouth within 24 hours. 3. you can already eat warm, cool and soft food after 2 hours, do not suck on the extraction socket. 4. within 2-3 days after tooth extraction, the Any blood is normal. If it is pulsating bleeding or bleeding is very large, it is recommended to go to the dentistry department for follow-up as soon as possible.