I while back I was flossing my upper left back tooth and a bit chunk of it just flew off leaving the inside exposed. The dentist repaired it with a white filling but it still hurts now. Maybe the nerve is dying. Any idea what I can do, other than have it taken out? And if I do have it taken out, is the standard procedure to replace it with a fake one? It’s three away from my canine towards the back.
Your best option is to contact your dentist.
However, if the tooth is dying, one option would be to remove the nerve; a.k.a. as a "root filling". This involves drilling the tooth out and removing the nerve and then filling it. This is a lot more involved than a normal filling; but is an option for saving a dead tooth.
As I already said though, you should contact your dentist to see what's going on with the tooth, so you can then work out what to do next.
Unsure how long, a while back, is, but if the nerve has been disturbed it may take a while to settle down. Or there may be an infection/inflammation. Lots of options but until you see the dentist and get the issue diagnosed it's not too useful to speculate.