1.Patients suffering from chronic wasting diseases such as tuberculosis, diabetes, hemophilia, hematological diseases, patients with intermediate or advanced tumors, or patients undergoing radiation therapy. 2.Patients suffering from mental illness and unstable psychological quality. 3.Patients suffering from hypertension, coronary heart disease, hemiplegia, cerebrovascular diseases, and those who cannot withstand dental surgery and other frailties. 4.Persons with drug and alcohol abuse, severe neurological weakness and poor physical fitness. 5, acute and chronic inflammation of the oral mucosa and peri-maxillary tissues. Such as acute gum infection, acute inflammation in the oral cavity, maxillary sinusitis, etc., should be cured after the implantation. 6.Embedded teeth and residual roots in the implant area. 7.Jaw bone cyst, osteomyelitis, benign and malignant tumors and abnormal bone lesions. 8, temporomandibular joint abnormalities Due to joint inflammation, deformity and masticatory muscle inflammation caused by mouth opening disorder, pain, opening and closing mouth movement trajectory abnormal and obvious popping. 9, occlusal abnormalities: those with habitual overbite should avoid implantation. 10. Poor periodontal and bone quality of the adjacent abutment teeth. 11, excessive resorption and shrinkage of alveolar bone, implant placement in the maxilla easy to wear the maxillary sinus; mandible easy to wear the mandibular canal. Severe resorption of jaw bone should not be directly implanted, should be implanted at the same time. 12, jaw fractures, including pathological fractures and traumatic fractures, should be implanted after healing. 13.People with severe grinding habits and poor oral hygiene.