Generally there are two types of restorations after root canal treatment, one is direct chair-side restoration and the other is indirect restoration, as follows: direct chair-side restoration: usually after the root canal treatment, the above cavity needs to be closed with material. An old material is introduced, which is silver-mercury filling material. Silver-mercury filling is cheaper but more durable and is only suitable for restorative treatment where some of the cavity types are better cemented. There is also a better material that can be applied, called modern composite resin restoration, which can be used in principle for patients who can use fillings to repair dental defects; indirect restoration: it has to be sent to a processing plant to be processed and then restored later. There are usually two kinds of such restoration, one is inlay, the smoothness of inlay, density and adjacent surface restoration effect is better; the other is full crown, is a kind of porcelain teeth, porcelain dental restoration up also to send to the processing plant for restoration, if the tooth defect is large, can also do pile core restoration.