The tooth pain after one year of crowning may be due to pulpitis or apical periodontitis, pulpitis, depending on the situation, choose root canal treatment or re-endodontic treatment. 1. Root canal treatment: If there is no root canal treatment after the tooth is crowned, and the tooth is painful one year later, it may be due to pulpitis or apical periodontitis. In this case, the crown will be removed and root canal treatment will be carried out on the tooth, and then the crown will be put back on after observing that the tooth does not have any obvious pain after two weeks. 2. Re-root canal treatment: after the tooth is crowned and root canal treatment is carried out, the tooth has pain after one year, which means that there is pulpitis, in this case, the original filling material needs to be completely cleaned up, re-root canal treatment is carried out, and the tooth does not ache and then put on the crown. If the tooth is painful after one year of crowning, you should go to the hospital in time to take root canal radiographs to determine whether it is apical or pulpitis, and then take the best treatment plan.