When I was little, the back of my third tooth (on top) from the back broke off. It was black on the back of it. I went to the dentist a few years ago and the dentist did a bonding on it and said that I would need a crown in the future. My insurance does not cover crowns so I haven't gotten one. Just recently, I've had this dull, throbbing ache in my tooth. Enough to be completely annoying. It also hurts the gum around my tooth. The bonding hasn't broken off nor do have an infection I believe. I take pretty good care of my teeth. Why does it hurt? Is there anything I can do? I can't see my doctor for another three months because he's so backed up so any advice would reallllllly help. Thanks.

I'd suggest you find another dentist who will see you as an emergency. It sounds as if the tooth may be dying and in need of a root canal. You may have an infection that you can't see unless an x-ray of the tooth is taken.