My 3 year old ran into a wall about a week ago and a knocked a tooth out of place. The next day it looked totally fine, so I figured we didn't need to go to the dentist and I'd just keep checking on it. Then yesterday it was suddenly discolored. So we went to the dentist and she said it looks fine for now and that it might just stay discolored until he loses it, or that his body could heal it itself, or that it could get infected and need to be removed. So for now I just have to keep an eye on it and bring him back in if it changes. Since it's possible it could heal on it's own, I figure there must be something I can do to help it along. Anyone have any experience with this?