Dental implants are possible 6 years after tooth extraction if the alveolar bone is in good condition and the extraction gap is not lost. Dental restoration is recommended within three months after tooth extraction. Due to resorption of the alveolar bone, the teeth on both sides of the extraction will tilt to the missing side, the teeth on the opposite side will elongate, and the extraction gap will be lost. Six years after tooth extraction if the amount of alveolar bone is sufficient and there is no significant reduction in the gap between the missing teeth, it is possible to have dental implants. Dental implants need to be observed for about six months after implantation, and after the implant nail in the jawbone and the alveolar bone are fully integrated and there is no rejection, the crown restoration above can be performed. Therefore, six years after tooth extraction, the alveolar bone has enough bone support, and the extraction gap has not been significantly reduced, it is possible to carry out denture restoration.