How long a dental implant will last is the first concern of the patient and also of the implantologist. The Swedish branemark implant system has a relatively long-term statistical observation report. A 24-year report published in 1990 since the first clinical implant was placed in 1965. Its 700 edentulous patients were observed in 759 maxillary or mandibular, with 4,636 implants placed for follow-up. The 5-year success rate reached 84% to 92% in the maxilla and 91% to 99% in the mandible; the 10-year success rate reached 81% to 82% in the maxilla and 89% to 98% in the mandible; and the 15-year success rate reached 78% in the maxilla and 86% in the mandible. It remains to be studied how long the implants will last, since more than 30 years have passed since the first implants were placed and the restorations and implants are still performing their normal functions. The retention time is an important indicator of the success of the implant. In the past, an implant retention rate of 85% at 5 years and 80% at 10 years was considered a condition of success, but nowadays it is more demanding. How long an implant lasts requires the joint maintenance of the doctor and the patient, and the success rate has little meaning for the patient.