Precautions before tooth extraction: 1. Rest well the day before tooth extraction. Do not engage in strenuous exercise and do not drink alcohol on the day of tooth extraction. If you are not in good health, you should avoid tooth extraction. 2. You should eat before tooth extraction, as tooth extraction on an empty stomach is likely to cause deficiency or fainting. Adjust your mind and eliminate tension before tooth extraction.3. Before tooth extraction, tell the doctor about the patient’s medical history so that relevant examinations can be conducted and treatment plans can be made: 1) Patients with hypertension: before tooth extraction, you must pay attention to rest, control blood pressure and wait for blood pressure to stabilize before tooth extraction; patients with heart infarction should have their teeth extracted only after 6 months after the occurrence of the latest myocardial infarction. For patients with cardiovascular disease, anticoagulant drugs such as aspirin can be suspended before and after tooth extraction. 2) Patients with diabetes: blood sugar should be controlled before tooth extraction surgery and antibiotics should be taken for 3 days before tooth extraction surgery to avoid wound infection. 3) Those with acute inflammation: tooth extraction should be suspended. 4) Patients with blood diseases or suspected blood mechanism disorders: such as hemophilia, thrombocytopenic purpura, leukemia, patients with liver cirrhosis, those with impaired liver function, patients who are prone to bleeding, etc. should generally be treated first or ask the doctor to decide whether the tooth can be extracted. 5) Patients with special periods or medical history of women such as menstruation, pregnancy, history of habitual abortion, etc. should be explained to the doctor. 4. It is best to have someone accompany the elderly for tooth extraction. There are several precautions after tooth extraction as follows: I. After tooth extraction, you should bite the gauze roll placed at the wound and spit it out after 40 minutes. It is normal for patients to have blood in their saliva on the day of tooth extraction. II. If there is active bleeding after tooth extraction and the amount of bleeding is high, the patient should not be nervous, but should follow up immediately and ask the doctor to handle it properly. For general bleeding, gelatin sponge or tannic acid powder or Yunnan Baiyao can be placed on the bleeding area, and then the bleeding can be stopped by biting down on the gauze roll for 30 minutes. If the bleeding is still more than after these treatments, it is necessary to further investigate the cause and then deal with it.1. The local cause of bleeding is gum laceration. If the laceration is bleeding, the gum tissue should be aligned and sutured. If there are fragments of teeth and broken free alveolar bone remaining in the extraction wound, the blood clot inside the extraction socket should be scraped and the foreign body removed, and the bleeding can be stopped. If there is inflammation under the root of the tooth, the bleeding after tooth extraction is also more, it is advisable to fill the extraction wound with iodoform gauze to prevent the gauze from falling off, and at the same time, anti-inflammatory drugs can be taken. 2. The systemic causes of bleeding are: where there are diseases of coagulation disorders, the bleeding after tooth extraction is more, and after finding out the causes, in addition to local treatment, systemic diseases should be actively treated. 3. Do not lick the wound with the tongue or touch the wound with fingers, and do not stuff the wound with unsterilized paper, cotton, etc. to avoid infection and septicization of the wound. If there is blood clot infection in the alveolar fossa, mostly occurs in 3-4 days after surgery, the blood clot becomes grayish brown, accompanied by corrupt and foul-smelling secretions, the alveolar bone wall loses the coverage of the blood clot and is exposed, the pain is more obvious, the medical term for this phenomenon is “dry socket”, and should be treated immediately. First, wash the wound with 3% hydrogen peroxide small cotton ball or repeatedly rinse with 1:5000 potassium permanganate solution, then put iodoform gauze in the sockets, also can add several drops of clove oil phenol or dicaine to help relieve pain, this method has anti-inflammatory, antiseptic, and promote the role of wound healing. This method has anti-inflammatory, antiseptic and healing effects. Change the medication 2-3 times a week, usually after 4-5 days there is new granulation tissue growth, the pain will be reduced, and with the increase of granulation tissue, the pain will gradually disappear. IV. Do not brush your teeth, rinse your mouth or smoke on the day of tooth extraction, eat soft food for 1-2 days, and the temperature of food should not be too high so that the wound can rest locally. Intense gargling and brushing will easily rinse off or touch off the blood clot and cause bleeding. V. It is normal to have slight pain after tooth extraction, and appropriate amount of painkillers can be taken. 6. For more complicated tooth extraction, the wound sutures can be removed in 5-6 days, and the appropriate amount of pain-relieving and anti-inflammatory drugs can be taken after the operation. VII. Except for the 3rd molar and multiple teeth, adults generally need to install dentures after tooth extraction, which can be installed in the hospital about 2 months after extraction.