1, the indications for implant denture 1) due to serious resorption of alveolar bone of edentulous patients, trauma or surgery and other reasons caused by the alveolar bone has a large morphological changes, resulting in poor retention of the restoration; 2) high requirements for restoration and conventional denture can not meet; 3) for various reasons can not adapt to the removable denture; 4) individual teeth missing, the adjacent teeth are not suitable for abutment teeth or to avoid damage to adjacent teeth injury; 5) jaw bone defect Those who underwent vascularized bone graft repair at the same time, or after 3-6 months of free bone grafting. Partial indications: width of alveolar ridge in the edentulous area, thickness, generally should be above 7mm. The commonly used implant nail diameter is 3.5/3.75/4/4.3mm, and should be surrounded by at least 2mm of bone; insufficient bone will lead to bone resorption implant failure. The distance from the top of the alveolar ridge of the missing tooth to the opposing tooth is >5mm to accommodate the restoration abutment and superstructure. 2. Contraindications to implant prosthesis 1) general health condition is not suitable for surgery or cannot tolerate implant surgery 2) skeletal systemic disorders: such as osteoporosis, achondroplasia, sarcopenia, etc. 3) mental illness, severe psychological disorders, alcoholism, etc. 4) acute inflammatory period in the oral cavity 5) soft and hard tissue lesions in the implant area (6) poor bite relationship, restricted mouth opening (7) severe misalignment, tight bite, grinding and other oral malocclusion habits, poor oral hygiene and inability to maintain oral hygiene (8) the amount of bone and bone density in the missing tooth area is not ideal, it is estimated that the requirements cannot be met through special implant surgery.