Why does the tooth still hurt after the treatment is considered to be due to the pulp is not clean, tooth infection, tooth loosening and other reasons, the specific situation should also go to the hospital in a timely manner to confirm the examination. 1. The pulp is not cleaned up: the morphology and structure of the teeth is more complex, in the oral cavity there is excessive curvature or narrow root canals, after the treatment of the residual pulp is not cleaned up, the local stimulation will cause pain, which leads to the symptoms of the treatment of toothache. 2. Dental infection: when the teeth have been treated, in order to timely care work caused by local infection, so that the bone is damaged, can lead to the symptoms of the treatment of toothache. 3. Loose teeth: After the teeth have been treated, they will be in the state of loosening, if the surrounding soft tissue work, which can cause pain. When the symptoms appear, should go to the hospital in time for examination, to clarify the cause of the disease, as soon as possible to accept the formal treatment.