I have a few questions about implants, but first here is a little bio on my circumstance. I have a couple of permanent teeth that never came in. Ultimately, I had to have the baby teeth extracted, since they were beginning to decay. The second one came out this January. Now I need to fill the gap that the baby teeth left behind and think I would prefer implants over etching the adjacent teeth to have bridges inserted.

It is my understanding that with state-of-the-art biomedical engineering implants of any kind (teeth, hip replacements, etc.) last at most 15-20 years. As a 37 year-old male that hopes to live past 57, is this a sound option? Once an implant fails, what concerns should I have about a new implant in the same location?