Dry caries, also known as chronic caries, is more common in the clinic, with dark brown cavities and a dry texture. Different treatment methods can be chosen according to the different degrees of caries. Generally speaking, it is often treated by filling, root canal treatment and tooth extraction. 1. Filling restoration: It is generally applicable to shallow caries, moderate caries and other caries with small scope or mild degree. At present, the commonly used filling materials include composite resin and glass ionomer. 2. Root canal treatment: If endodontitis or apical periodontitis has been caused, root canal treatment is needed. The patient needs to clean the infected material and disinfect it first, then fill the root canal, and finally close the cavity to prevent it from expanding further. 3. Tooth extraction: If the scope of caries is large and the tooth has lost its function, and the patient meets the indications for tooth extraction, then tooth extraction can be carried out. At the same time, patients should pay attention to oral hygiene to avoid the accumulation of food debris in the cavity to produce bacteria, which will cause further damage to the tooth. It is recommended that the patient seeks medical attention in a timely manner to avoid further development of cavities, which may cause further damage to the tooth.