The most likely cause of toothache caused by eating cold food is tooth decay or pulpitis, when the cavity area is large, eating cold food will cause the tooth’s transient pain, and should go to hospital for treatment in time. First of all, the infected tooth tissue should be removed and a layer of pulp protection material should be placed at the bottom of the cavity, clinically most of the cavities are cushioned with calcium hydroxide, followed by conventional cavity filling. For some teeth with severe sensitivity and pulpal congestion, the doctor usually also pacifies the congested pulp by filling the surface of the tooth with zinc oxide to pacify the nerve, and after the nerve congestion improves, the cavity will be filled. Pulpitis can also cause severe pain when the tooth encounters cool stimuli, in which case root canal treatment will be performed to remove the infected nerve. Patients with periodontitis will also suffer from tooth pain due to the resorption of the alveolar bone and the exposure of the tooth root.