Earlier today I felt a lump behind one of my 12 year molars. At first I thought it was a sore, but when I touched it it was obviously a tooth coming through (or at least a fragment of one). The thing is, the wisdom tooth was removed in 1994. It seems unlikely a bone fragment would take that long. I’ve read that a second wisdom tooth can come through in the same spot, but only very rarely. Has anyone else experienced something like this. Mods, I hope I posted on the right forum. As a very wise man once said, I want facts. I’m not interested in your freaking opinions. 
dentist here. tough to say without x-ray of course, bone can come through years later. Usually bone would be a fairly sharp piece and not have the feel of a tooth. Yes some people have additional teeth behind the wisdom teeth. I’ve seen quite a few 4th molars and even one patient with 5th molars. Oral surgeon had fun with her. Assuming they took a panoramic x-ray prior to removal of your 3rds any additional teeth should have shown up then so more likely bone and just doesn’t feel like it.
It’s not hurting, so can I just forget about it until my next dental appointment? You can bill me for your answer; I’m good for it. Obviously I haven’t had anything erupt from my gums for a long time, so I don’t really remember exactly what a tooth coming through felt like.
depending on when the next appt. is, probably. If it is bone and starts cutting the gums you may want to go in fairly quickly. if on further eruption it doesn’t look like tooth or bone I’d getting it looked at right away.
Thanks. The check’s in the mail. I should be getting an appointment soon anyway.