Artificial dental implants are considered internationally as the first choice for restoration of missing teeth, and they can be used in various cases of tooth loss. (2) Patients with severe alveolar resorption in the lower jaw, who have difficulty in wearing traditional full dentures, have poor function and cannot wear them firmly. (3) Wearing traditional movable dentures with poor retention, non-functional mucosa can not tolerate. (4) Those who have special requirements for the beauty and function of dentures. (5) The remaining teeth around the missing teeth have problems and cannot be traditional dentures.