Caries is the primary cause of pulpitis and periapical infection in milk teeth, in addition, dental trauma and dental development malformation can also cause pulpitis and periapical infection in milk teeth. The characteristics and hazards of pulpitis in milk teeth 1. Acute attack of apical infection in milk teeth can cause rapid expansion of periapical infection, reaching the subperiosteum, causing severe pain and tooth loosening, and untimely treatment can lead to facial interstitial infection, facial soft tissue swelling, causing high fever, increased blood white blood cells and other systemic infection symptoms. 2, the milk teeth themselves will be replaced, there is physiological root resorption, coupled with low calcification of milk teeth, easy to cause root resorption, resulting in loose teeth and premature loss. Especially when pathological root resorption + physiological root resorption exist at the same time, the speed is faster, and the clinical treatment effect of periapical periodontitis is poor compared with adults. 3. Below the baby tooth is the growing and developing inherited permanent tooth embryo. Chronic apical periodontitis of the milk teeth can invade the permanent tooth embryo, resulting in incomplete development, malformation, eruption disorders, or even failure to erupt of the inherited permanent teeth. Therefore, once the chronic periapical inflammation of the milk tooth involves the permanent tooth embryo, it is an important indication for the extraction of the tooth. The presence of abscesses and fistulas is a reliable diagnostic basis for chronic periapical inflammation of the papillary teeth, which is related to the root morphology and orientation. 5. Since the apices of milk teeth can sometimes be living pulp, the difference between pulpitis and apical inflammation in milk teeth is mainly radiographically. Diagnosis 1, history: response to hot, cold, sour, sweet and other stimuli, the presence of food embedment and spontaneous pain. 2.Clinical examination: check the color, shape and quality change of hard tissue of the tooth, the site, depth and type of caries. The main methods are: visual examination, probing, percussion, etc. 3.X-ray examination is the most commonly used examination means, which is the main method to distinguish pulpitis and apical inflammation of milk teeth. Treatment The treatment methods for pulpitis in milk teeth are crown pulpotomy with partial preservation of the pulp and pulp extraction (root canal therapy). The former is indicated in the early stages of pulpitis, when the inflammation is limited to the crown and the root pulp is basically uninvolved; when there is diffuse inflammation of the pulp and even pulp necrosis, only pulpotomy can be performed to preserve the tooth. The main treatment for periapical inflammation in milk teeth is pulpotomy; once chronic periapical inflammation of the tooth has involved the permanent tooth germ, tooth extraction is the last resort. Since the damage to teeth requiring crown pulpotomy and pulp extraction is usually significant, the best restorative means for milk molars is a metal pre-crown. Prevention Prevention of dental caries and trauma that can lead to pulpitis and periapical inflammation in milk teeth. Once caries and trauma occur, they should be treated promptly to avoid the development of pulpitis and periapical inflammation.