5 years ago I had an emergency root canal, and crown done on a molar (#36).
Last fall I had pain in the root canal tooth, & bad infection. I mean bad, and I felt terrible for months. Dentist said he could re-do the root canal or pull. Pain went away after being on antibiotics, so I let it slide.
6 months later, more pain, and tooth was hitting hard. I decided to start off with a new dentist. He said it was hitting hard because the tooth was again badly infected, and it was pushing the tooth up. The infection was so bad that I have bone loss, he showed me the x-ray with dark spot on the jaw bone. He referred me to an endodontist, who saw me the next day, who found that the tooth had a broken root, it did not show up on the x-ray, so he used a microscope and put a pick in that caught on the crack, so there was nothing else to do but extract the tooth. More antibiotics. May 1st, I was referred to have the tooth pulled, and had to be put under. More antibiotics. Cost me $760.00 upfront, but my insurance coverd $670, so $90. out of pocket. I miss my tooth still after 6 months :-(
Research I found that most root canals do not last more than 10 yrs btw. If I had to do it over again, I would not have had the root canal done in the first place, it would not be worth the pain, bone loss, being on so many antibiotics and $$.