Pulpitis is an inflammatory disease caused by the invasion of bacteria or toxins into the pulp located in the center of the tooth, with spontaneous, paroxysmal pain as the main symptom. What is pulpitis all about? Pulpitis is often classified clinically as reversible pulpitis, irreversible pulpitis, pulp degeneration and pulp necrosis. Pulpitis is most often treated by removing the pulp of the tooth. The vast majority of periapical lesions, especially inflammatory ones, are secondary to pulp disease. In the case of periapical lesions, the pulp can also be affected. Acute pulpitis is an acute inflammation of the pulp tissue, the source of infection is mainly from the deep pulp, the infection of the pulp can cause apical infection through the apical foramen, the main clinical feature is severe pain, the general pain medication is not effective, the later stage can develop into pulp gangrene, the treatment mainly has open pulp and medication for pain relief. The main cause of pulp inflammation is infection. Any cause of bacteria and its toxins invading into the pulp cavity will cause inflammation of the pulp. The pulp tissue enters the pulp cavity in the center of the tooth through the apical foramen and is surrounded by hard dentin and enamel, which are not subject to bacterial attack under normal circumstances, but bacteria can invade and infect the pulp when the hard tissue of the tooth is damaged for various reasons. When the caries damages the enamel, reaches the deep layer of dentin and even penetrates the dentin to reach the pulp chamber, the bacteria in the mouth will infect the pulp and cause the inflammation of the pulp. Other causes include dental defects caused by abnormal tooth development, and the pulp is exposed by fractured crowns caused by accidents, which also directly damage the pulp. In addition, in severe periodontal disease, the periodontal pocket reaches deep into the apical region and bacteria can also enter the pulp cavity by the apical foramen or some tiny branches of the root causing pulp inflammation. The causes of pulpitis are bacterial, physical, chemical and idiopathic factors. 1. Bacterial factors Pulpitis can be considered an infectious disease, and bacteria are an important causative factor for pulp disease. There are three ways to cause pulp infection: infection via dentition, periodontal infection and blood-borne infection. Bacteria can directly infect the exposed pulp when caries, traumatic tooth fracture and accidental pulp exposure during drilling and grinding, pulp exposure from wedge-shaped defect, pulp exposure from severe abrasion in the elderly, pulp exposure from deformed central cusp fracture or abrasion, pulp exposure from deformed lingual fossa or bottom of deformed lingual sulcus without enamel coverage, and pulp cavity from cryptic fracture, such as thin dentin covering the pulp tissue, bacteria and their toxic products can cross the dentin tubules to reach the pulp cavity and Bacteria and their virulent products can cross the dentin tubules to the pulp chamber and cause pulp infection. The bacteria through the periodontal tissue can also be from the periodontal pocket to the root tip, through the apical hole into the pulp chamber caused by retrograde infection, this periodontal infection of the pulp caused by pulpitis is called retrograde pulpitis; through the blood source of infection caused by pulpitis is very rare. 2, physical factors Acute dental trauma, such as traffic accidents, sports, violent fights so that the teeth are violently impacted or eating suddenly chewed to hard objects, as well as accidents in medical work, such as orthodontic treatment with excessive force, moving teeth too fast, extraction of teeth accidentally injured adjacent teeth periapical, scraping deep periodontal pockets when the damage to the apical vessels caused by mechanical trauma, traumatic occlusion, fillings or other restorations too Mechanical trauma such as chronic bite trauma dentition caused by high. 3, chemical factors Intra-dental resorption, extra-dental resorption can cause some unexplained pulp lesions. Acute pulpitis Acute pulpitis can develop from pulp congestion or from an acute attack of chronic pulpitis. Depending on the course of inflammation, acute pulpitis can be divided into a plasma phase and a suppurative phase. 1. Acute pulpy pulpitis is often a continuation of the development of pulpal congestion. The extent of the lesion is limited to the crown pulp for localized pulpitis. When the lesion spreads to the root pulp, it is a total pulp pulpitis. 2. Acute purulent pulpitis Acute purulent pulpitis has a short course. During the brief pulp phase of pulpitis, the exuded leukocytes continue to necrotize and liquefy, forming an abscess, which is acute purulent pulpitis. Chronic pulpitis Chronic pulpitis is the most common type of pulpitis in clinical practice, with atypical clinical symptoms, and in some cases there may be no spontaneous pain. If the virulence of the bacteria invading the pulp is low and the body’s resistance is strong, the inflammation of the pulp tissue mostly manifests itself as a chronic process. If the exudate of acute inflammation is drained, but the inflammation is not completely eliminated, it can also be transformed into chronic inflammation. Conversely, if the body’s resistance is reduced, or if local drainage is poor, chronic pulpitis can be transformed into acute pulpitis, i.e., an acute attack of chronic pulpitis. 1.Chronic atretic pulpitis The pulp is not yet exposed, but the deep cavity, crown filling or other hard tissue disease near the pulp can be detected, and there is no pulp hole visible to the naked eye after removing the decaying and necrotic material. If the virulence of bacteria does not increase and no new infection invades from outside, the encapsulated lesion will not develop outward for a while, so the chronic inflammation can be maintained for a long time. There is no obvious spontaneous pain or occasional dull pain clinically, but almost all patients have a long history of painful cold or hot irritation. 2. Chronic ulcerative pulpitis The pulp tissue is exposed and ulcers are formed on the surface. There is usually no obvious spontaneous pain, but severe pain occurs when food is embedded in the cavity of the affected tooth. Patients are afraid of pain and use the affected tooth for a long time, so that a lot of soft tartar and tartar accumulate. Patients often have a history of spontaneous pain, and another typical symptom is severe pain when the affected tooth is provoked by cold or hot stimulation. 3.Chronic hyperplastic pulpitis occurs mostly in young people, the pulp has been exposed, due to the mild but persistent stimulation, causing hyperplastic reaction. There are red “mushroom” shaped granulation tissue in the large and deep cavity of the affected tooth. The pulp polyp can fill the whole cavity and reach the occlusal surface, it is painless to probe but bleeds easily. Generally, there is no spontaneous pain, sometimes the affected tooth feels pain when eating or has bleeding phenomenon when eating, therefore, it dares not chew food with the affected side for a long time. Due to long-term disuse, tartar accumulation is often seen in the affected tooth and its adjacent teeth.