When the infection of tooth decay reaches the pulp and leads to acute or chronic pulpitis, nerve-killing treatment, also known as root canal treatment, is required, and a specific clinical examination is performed. First, according to the subjective symptoms, patients suffering from pulpitis will have severe pain in the teeth, mostly after eating hot or cold food, or after biting into hard objects, some patients will have spontaneous severe pain at night, and in the case of chronic inflammation patients will have prolonged biting discomfort. Secondly, we should combine with clinical examination, such as taking X-ray apical film to observe whether the size of the cavity has reached the pulp and whether there is inflammation in the apical region of the root tip of the tooth, once it has reached the pulp and even appeared apical inflammation, such teeth need to do root canal treatment.