Teeth after filling hot and cold sensitivity, need to be treated according to the cause of the symptomatic treatment, dentin allergy caused by desensitization or re-filling treatment; caries caused by removing necrotic tissue, and then restorative treatment. 1. Dentin allergy: it may be caused by dentin allergy, when filling, if the filling material does not fit closely, it may lead to oozing out of the filling, so the symptoms of tooth sensitivity will appear, and need to consult the doctor in time, and re-filling. 2. Dental caries: If the decayed material is not removed in time during the filling period, it may lead to secondary caries, so there will be further symptoms of hot and cold sensitivity of the teeth, and it is necessary to consult a doctor in time to remove the decayed material, and then carry out restorative treatment, and it can be taken as composite resin direct bonding restorative treatment, so as to avoid aggravation of dental caries. 3. Desensitization treatment: some patients with dental fillings teeth hot and cold sensitivity, may be due to material polymerization and contraction of the reaction, if the caries hole is deeper, after surgery, eat too cold and acidic food will cause tooth sensitivity. Usually pay attention to diet warm and cool, oral hygiene, usually about a month will improve on its own. You can also try to use desensitizing toothpaste. It is recommended that you have a one-week checkup after the filling, and if the sensitivity worsens, you may need to re-draft the treatment plan according to your own situation. After filling the teeth, usually need to pay attention to personal hygiene, to avoid bacterial growth, need to be regularly reviewed, if the symptoms of hot and cold sensitivity, need to consult a doctor in time to avoid serious complications.