I had a tooth that was badly destroyed with a part melting and missing because I was mindless and not washing my teeth regularly. Anyway I visited the dentist and she performed a root canal operation on it, filling it up. It's on the upper left side and it is the main tooth I chew on so I do not want to lose it.
A week later (today) after the root-canal I was still filling pain when I put pressure on the tooth, so I went in again today. She looked at my xray and did some measurements grabbing different drills of different sizes to drill my tooth (something she didn't do at the first time). Then she started drilling and after a point she kept changing drills small like needles every 30 seconds, putting on them some small dose of a white/yellow substance before putting them in. She was also putting some kind of antibiotic liquid I think after every drill. When the tooth was completely drilled we had a 20 minute brake and by the time the anesthetic started wearing off. She didn't renew the anesthetic and she proceeded adding some sticks in the roots, something called thermafill and burned them at a point.
My first two roots hurt when she insterted the sticks, but when it came to the third and main root I almost fainted from the pain when she was pushing an F4 size (much bigger than the other two) stick into my roots. She said this procedure is a bit better to be done without anesthetic and it's normal to feel pain. I still feel pain in the tooth now 2 hours after the operation so I took the medicine she prescribed for pain relief.
My questions are:
I don't remember her doing any of the stick insertion, or complicated drilling at the first time I did the root canal, where I didn't feel any pain at all. What did she do differently? Is it guaranteed that I will not feel pain when chewing on the tooth after this ends, or will I need an extraction? How long will the pain normally last? Is there a chance of losing the tooth after some years? What is this procedure called?