After root canal treatment, the tooth hurts when biting, you can first observe, if the pain can not be relieved, you can take anti-inflammatory drugs, or go to the hospital for follow-up examination and then symptomatic treatment. 1. Self-observation: Generally speaking, after root canal treatment, part of the root filling paste and filling materials such as gum may stimulate the periapical tissues, thus leading to biting pain in the tooth, which will generally return to normal, so you can self-observation, and then consider consulting the doctor if any discomfort occurs. 2. Taking anti-inflammatory drugs: During root canal treatment, the infected material and debris in the root canal may be pushed out of the apical foramen, which may lead to occlusal pain again after treatment, so you can take metronidazole tablets and other drugs under the guidance of the doctor for anti-inflammatory purposes. 3. Follow-up treatment: If the tooth has been biting pain after completing the root canal treatment, it is necessary to go to the hospital stomatology department in time to find a doctor to take the apical film and occlusal examination, and adjust and grind the occlusal height in time to prevent the tooth from biting pain due to the occlusal overbite; in the case of overfilling and underfilling of the root tip that leads to the biting pain, the need to carry out the second treatment.