Remnant crowns and roots of anterior teeth are aesthetically displeasing, and it is an important issue to determine whether or not a primary patient’s crown or root can be saved. If they are removed directly, the subsequent restoration of the patient is far more costly and time consuming than utilizing their own roots and crowns. If the crown and root preservation restoration requires piles and crowns to be completed, it is still best to be able to use their own existing teeth. In the past, most of the cast metal piles and metal porcelain crown restoration, due to metal piles easy to cause root fracture, metal porcelain crown easy to induce gingivitis, gingival black line and metal allergy and other defects, affecting the long-term restoration effect. In recent years, in order to make up for these defects, fiber piles and all-ceramic crowns are increasingly used for the preservation and restoration of residual crowns and roots. However, it is very important to determine whether and how the crown and root can be preserved for the first time, which is the key to the success or failure of the restoration. The preservation of restoration is based on the following conditions: 1) periodontal and bone support conditions; 2) length of the crown pile, surface structure of the crown pile morphology; 3) mucoadhesive medium; 4) relationship between the crown and root surface; 5) fracture resistance of the crown pile and quality of root canal treatment, etc. After systematic and meticulous oral examination, x-ray dental films should be taken to further determine the specific situation of the residual roots through measurement: 1, the value of retention treatment, such as with periodontal disease, root loosening, root shortening, apical lesions can not be effectively controlled and improved are not retained value. 2, whether the root canal treatment is perfect, whether the basic requirements of composite restoration. Such as whether the root filling reaches the position, overfilling and underfilling are hidden dangers for future restoration. 3, whether the need for pre-prosthetic treatment, such as the section of the residual root is located in the lower subgingival, surgical gingival circumcision or orthodontic root retraction treatment is required.