Cavities are commonly known as dental caries. It is the bacteria in the mouth to erode the weak parts of the teeth, resulting in cavities on the surface of the teeth, and then eat sweet food acid, pain; until the teeth “nerve inflammation”, manifested as severe pain. The main reason for its formation is plaque, plaque is a layer of almost colorless film on the surface of the teeth, the bacteria in it will use the sugar or starch in the food to produce acid, corrosion of dental tissues, the formation of cavities, i.e., cavities; in serious cases, it will lead to necrosis of the teeth and fall off. For cavities that have formed, it is important to go to the hospital in time, so that the dentist can take timely measures to fill the cavity and prevent it from continuing to deteriorate. 1.How to treat tooth decay? The treatment measures for toothworms are mainly chosen according to the depth of the cavity and the condition of the nerve, which mainly include ordinary fillings, inlay restoration and root canal treatment. In the cavity does not reach the nerve and the nerve is in good condition, usually choose fillings or inlay repair; in the case of irreversible necrosis of the nerve, you can only choose to “extract the nerve”, that is, root canal treatment. 2, insect tooth treatment plan In the case of good nerve condition, the common treatment method is to remove the carious tissue on the basis of repairing the tooth defects. There are two common ways to choose, one is a simple filling, can effectively terminate the progress of the worm tooth, and restore part of the chewing function, common such as resin filling restoration, that is, often referred to as dental fillings. The advantage is that it is close to the color of the tooth and can be used on both anterior and posterior teeth; the disadvantage is that due to the shrinkage of the filling material during light curing, it is generally used for the restoration of insect teeth with relatively small defects. If the cavity of the worm tooth is very large, or involves the neighboring surfaces of the tooth, resin fillings are not so suitable in the long run, and are prone to breakage and fracture, leading to recurrence of worm tooth or plugging, and so on. In the case of good nerve, compared to fillings, there is a better way of restoration that inlay repair, it is a kind of embedded dental cavity used to restore the form and function of the defective dentition of the precision casting body, can be regarded as a tailor-made for the teeth of the “restorations”, due to the inlay in the form of hardness and teeth with a good degree of match, and smooth surface is not easy to adhere to biological organisms, and the surface is not easy to adhere to biological organisms, and the surface is smooth, and the surface is not easy to adhere to biological organisms. And the smooth surface is not easy to adhere to biofilm food debris, reducing the possibility of secondary caries, for worm tooth repair has good long-term efficacy. 3, root canal treatment precautions (1) root canal treatment is not always a complete treatment, the doctor is often based on the patient’s clinical examination, step by step treatment, generally speaking, root canal treatment should be divided into 2-4 visits to complete. If there is uncontrolled infection or a large response to treatment then the number of treatments will need to be increased. (2) Due to the complexity of root canal treatment, the doctor must be familiar with the anatomical knowledge of the tooth structure and skillful operation techniques, and at the same time, special matching root canal treatment instruments and equipment and materials are required, thus, the cost of root canal treatment is relatively high. (3) Pain and swelling after root canal treatment is the most common complication. Mild discomfort or mild pain will disappear the next day. Severe pain and swelling require anti-inflammatory treatment, but do not affect the final outcome. (4) For curved root canals and calcified root canals, often due to anatomical reasons can not be successful, and individual patients may even occur needle breakage. (5) In the process of root canal treatment, the doctor often requires the affected tooth to take X-ray film before, during and after the root canal treatment to help diagnose, understand the location of the pulp chamber and the number of root canals and morphology, measure the working length of the root canals and provide a basis for comparison for follow-up and evaluation of the efficacy of the treatment in the future. (6) The tooth is more brittle after root canal treatment, try not to chew too hard food to avoid tooth fracture. Postoperative crown restoration is recommended to prevent tooth fracture and prolong the life of the tooth.