Three months after tooth extraction and then set the reasons: 1, after tooth extraction, the root of the socket where the empty, covered by blood clot gradually formed fibrous tissue and granulation, prompting bone filled with alveolar fossa, with the prolongation of time, the newborn osteoblasts gradually reduce the resorption rate of alveolar bone is reduced, three months basically flat, you can set the teeth, to be able to obtain a stable result; 2, the restoration of the denture will be more closely with the mucous membranes, and does not Retain food residues, causing putrefaction or causing neighboring surface caries, if premature veneering, the gums will continue to shrink, so that the denture produces gaps, affecting aesthetics, and sometimes lead to food blockage, resulting in traumatic ulcers and pain. Implant restoration must be carried out after three months, after placing the implant, the new bone will form a stable bone healing with the implant.