The clinical manifestations of chronic pulpitis do not usually occur with severe spontaneous pain, but sometimes there can be paroxysmal, vague pains that are not particularly pronounced, or dull pains that occur at regular intervals throughout the day. Chronic pulpitis has a long course and patients may complain of a long history of hot and cold irritation, so the inflammation tends to spread to the entire pulp and the periodontal membrane at the root apex, resulting in the affected tooth often showing discomfort and mild biting pain. Patients can usually locate which tooth is in pain. Chronic pulpitis is classified into chronic atretic pulpitis and chronic open pulpitis based on histopathological findings to see if the pulp cavity has been penetrated. Atretic pulpitis means that the pulp is not yet exposed, whereas open pulp means that the pulp cavity has been opened to the outside world. The tissue response exhibited by pulp cavities that are exposed differs due to different conditions such as the blood supply to the pulp. In addition to the common manifestations of chronic pulpitis, each of these three types of chronic pulpitis has its own characteristics, both in terms of the patient’s symptoms and clinical examination. Therefore, if you find symptoms of pulpitis, you need to go to the hospital for timely examination.