I had one root canal done, a horror story. The dentist filled it with mercury. It was dreadful from the get go. I never suspected fillings for the cause of why i felt so bad up front. When they finally put the crown on that tooth, oh my gosh, what a nightmare. Constant headaches, constant.. real bad. I had it extracted. just several weeks after spending $1500.00 on that dumb tooth, which btw was fine till the dentist touched it.

I'm not real sure it's actually possible to fix a tooth that has cracked and exposed the root. she can have the crown finished (personally I would not) and all that, but she'll just be suffering with it if she's suffering already, the crown makes things ten times worse because there are metals in the crown.... and then downline after the suffering for the sake of a tooth she'll end up getting it pulled anyway. If it cracked during amalgam replacement it was probably already slightly cracked or ready to go and leaking anyway.

I'd opt for extraction on that one. I have had a few extracted and will probably do a couple more rear molars this summer. It's traumatic losing your first tooth that way but as in my case, it's a choice between a few pretty (and very expensive) teeth or my overall health. I opt for overall health. so far so good on that for me. you get used to the teeth being gone and gone is gone, no worries.

Get the tooth cut out via a good oral surgery technique (not 'pulled') and there will not be any fear of cavitations, and very little swelling or pain after. Be sure to remind the dentist to scrape the periodontal ligament out, sometimes they are just lazy (you can add any other expletives in there you'd like also) and don't do it unless you request it.

BTW, if the dentist tells you you have to pay for the crown even if she decides to get the tooth removed, just ignore him. You do not have to pay for the crown after an unsuccessful root canal. Don't throw your money away. You'll be looking for it downline to heal.