The dental term for a lost tooth due to an injury is “avulsed.” An avulsed tooth is a fully intact tooth that has come out of the tooth socket. Any part of a tooth that comes off while the tooth root is still in the bone is called a fracture or a break. If a tooth fractures at the gum line, likely the root will need to be extracted, and the tooth is not salvageable. But, if the entire tooth comes out of the socket and you can retrieve it unharmed and get to a dentist immediately, you may be in luck.
If the tooth was salvageable and your dentist was able to place it back in the socket, the bone will firm back up around the root of the tooth over some time. The tooth will need a root canal treatment because the blood supply and the nerve have been severed. If the tooth was not salvageable, an implant or bridge must eventually be placed to fill the space. Of course, if it was a baby tooth that was lost, it is still essential to get to the dentist immediately, but it is may not be necessary to place the tooth back in the socket.