[Disease Overview] Pulp disease refers to diseases of the pulp tissue, including pulp inflammation, pulp necrosis and pulp degeneration. As the pulp tissue is surrounded by hard tissues of the tooth, it is only connected to the outside world through the apical foramen and lateral root canals. When the pulp is acutely inflamed, the blood vessels are congested and exudate accumulates, resulting in an increase in pressure in the pulp cavity, which compresses the nerve and makes the pain extremely intense due to the stimulation of inflammatory exudate. Etiology】 1, microbial infection Bacteria are the most important pathogenic factors of endodontic disease, the bacteria are mainly parthenogenic anaerobic bacteria and specific anaerobic bacilli, such as streptococci, actinomycetes, lactobacilli, etc.. The ways of bacterial infection are as follows: (1) Infection through dental defects, such as deep caries, dental trauma, severe wear and other serious dental defects, bacteria and toxins invade the pulp through dentin tubules or pulp penetration points. (2) Periodontal infection, bacteria and toxins invade the pulp through the periodontal pocket, through the apical foramen and lateral root canal. (3) Hematogenous infection, bacteria and toxins invade the pulp through the blood is very rare, but not impossible. (2) Chemical stimulation (1) Drug stimulation Post-cavity disinfection drugs, such as phenols, can cause pulp stimulation. (2) Filling material stimulation deep cavity directly with zinc phosphate cementum bedding, composite resin direct filling, etc. may stimulate the gap. 3, physical stimulation (1) temperature stimulation cavity making such as the use of gas turbine machine must be sprayed with water to cool down, otherwise lead to pulp congestion, bleeding caused by inflammation. (2) Current stimulation If there are two different metal restorations in contact with the oral cavity, through the saliva can produce a potential difference, there is a certain stimulation of the dental pulp. (3) The effect of air pressure changes In high-altitude aircraft or deep water diving, air pressure changes can lead to acute attacks of pulp lesions. (4) Trauma such as diabetes can cause pulp degeneration, tumors can also affect the pulp, blood-borne infections caused by pulp disease is rare. Clinical manifestations] 1, acute pulpitis (Acute pulpitis) mostly caused by trauma, mainly manifested as severe spontaneous pain, characterized by the following: ① pain is often sudden onset, early intermittent, generally lasting about a few minutes, followed by several hours intermittent period, the patient can still refer to the affected tooth. With the development of the disease, the attack period lengthens and the interval period shortens, and gradually changes to persistent severe pain, and dissipates along the distribution area of the three ipsilateral nerves (such as the upper teeth to the cervical, preauricular and zygomatic-cheek areas; the lower teeth to the subauricular, postauricular and mandibular areas), and the site of the affected tooth often cannot be clearly indicated. ②The pain is often more intense at night, especially when lying down. ③In the early stage, cold and hot stimulation can stimulate or intensify the pain, and the pain is more obvious with cold stimulation; in the late stage or when abscess is present, hot stimulation is painful, and cold stimulation can only temporarily relieve the pain. In the later stage, the patient often contains cold water or inhales cold air to relieve pain, and such symptoms are helpful for diagnosis. This symptom is helpful for diagnosis. ④ Examination often reveals that the affected tooth is pulp-perforated and the pain is obvious. 2, chronic pulpitis (Chronic pulpitis) Because most of the caries and other chronic lesions, there is a long-term continuous stimulation of the pulp, which can cause the pulp to develop a chronic inflammatory process. During the development of chronic pulpitis, if the polymorphonuclear leukocytes increase, the lysosomal enzymes released will also increase, and the inflammation will intensify, and the symptoms of acute attack will appear clinically. Chronic damage to the dentition, periodontal disease, and chemical stimulation of dentin can cause the pulp to show a chronic inflammatory process. Chronic pulpitis is clinically divided into three categories: chronic atretic pulpitis, chronic open pulpitis and chronic hyperplastic pulpitis. Chronic open pulpitis is also known as chronic ulcerative pulpitis. Chronic proliferative pulpitis is also known as pulp polyp. The diagnosis of chronic pulpitis is based on: ① long-term irritating pain, radiographs show that the periapical area has a widened membrane cavity and broken hard plates; ② history of spontaneous pain; ③ probing has penetrated the pulp, bleeding and severe pain; ④ there is deep caries or deep blind pockets or severe chronic damage to the tooth. Pay attention to the pulp polyp and gingival papilla growth into the cavity of adjacent teeth, and distinguish it from the polyp with pulpal penetration. Otherwise, the consequences are serious. Treatment】 Indirect pulp capping can be used in the initial stage of chronic pulpitis. In other cases of chronic pulpitis, dry pulp surgery is used for posterior teeth, and pulp debridement is used for anterior teeth. Pulpotomy can be used for young people, especially for permanent teeth whose roots have not yet developed. In acute attacks of chronic pulpitis, the first emergency treatment is to open the pulp and drainage under local anesthesia, and medication for pain relief. After the pain is relieved, the posterior teeth are treated by dry pulp, the anterior teeth are treated by pulpotomy, and retrograde pulpitis is treated by pulpotomy combined with periodontal treatment.