I had 2 dental implants placed, one on each side of lower jaw. When the implants were uncovered at 6 mths one of the implants fell out. The current approach is wait 3 months and re-do. He has not given me an indication as to why it failed. I am nervous to try again. What do I need to consider/reconsider for the second time? Notes: I did orthodontics to create space for the implants. No bone grafting was necessary. I was an ideal candidate, non-smoker healthy, 30 year old female.