Clinically, many people will ask if tooth decay can no longer be filled and must be extracted, in this case, it is generally not easy to extract. However, if the defect is too large, it is necessary for the prosthodontist to evaluate whether the affected tooth can be restored to its function by making a restoration. Generally, the affected tooth has a crown, corresponding to a certain resistance shape, can be prepared through the crown, made into a high inlay or full crown. This is similar to a cap being placed on the tooth. In addition, even if most of the crown is missing, it can also be restored by means of a pile core crown, which can be made in the pulp of the remaining root of the tooth, prepared into an upper pile core, and then made into a full crown over the pile core, which can also make the decayed tooth serve for a longer period of time.