My surgeon assured me at least 20 years. Then with present day technology they do a revision. Of course technology continues to improve.
Longevity depends on many factors including the implant but also on such things how well it is implanted (go to the best, most experienced surgeon you can) and the activity level and weight of the patient. The overall health of the patient can also impact the implant which is why they are so careful about having you take antibiotics when you get your teeth cleaned.
Best of luck to you