The conditions for pile crown restorations are as follows: 1. Large defects: The number of piles used to restore the shape of the tooth is determined clinically according to the number of surfaces lost in the patient’s affected tooth. If 1-2 facets of tooth loss occur in the posterior teeth, two fiber piles or metal piles may be chosen to be placed in the distal mesial and proximal mesial roots as a way to support all the tooth tissues for full crown restoration; 2. Good roots: When all the crowns of a tooth are destroyed, but the roots are still intact and of sufficient length, fiber piles may be implemented in the roots and then restored to the tooth shape by means of pile core restoration and full crown restoration. Therefore, the tooth for pile crown restoration should have a good root, which can provide a resistant shape of the root after root canal treatment. Finally, good occlusal function and shape are restored after crown restoration.