I've rarely experienced pain in my dreams, but it has happened a couple of times. It wasn't an intense pain at all though. Two months ago I dreamt that I was in a speedboat and it crashed and I was violently thrown out of the boat cuz of the crash. I then smashed through a wooden bridge and fell on the grass, bounced off the grass and landed on a road. The only part that hurt was the part where I landed on the asphalt road, but it wasn't really intense.

I think pain in dreams is quite similar to any other sensation you have in your dreams. If your mind knows what something smells like, it can reproduce that scent in your mind during your dream. If your mind knows what pain feels like, it can reproduce it in your teeth or your aching bones.