Root canal - v- extraction

busiscoming2

I had a low grade infection in my upper right second from the rear molar. Had antibiotics and my (NHS) dentist did a root canal. He could only reach one of the canals but said that was the infected one. He said if it doesn't work I'll have to either be referred to a private endontist at an estimated cost of £800 for them to do the other two roots, or I could have it extracted.
It's been about 3 weeks and it's started to niggle occasionally. I have an appointment to go back next week to have the proper filling done. I really don't know what to do if he says this RC has failed. 
I'd struggle to pay the private costs but am worried about an extraction as I apparently have large sinuses and that can cause problems?
Any help or advice would be great, thanks. 

Toothsmith

If only one canal has been found, then the root filling has failed.  The canals are all linked, and the others will flare up one day. You might get away with it for a while, but it will let you down, and most likely when you least want it to.

Be advised by the dentist who can see it, or the specialist who looks at it if you go for that option (They won't do it if they don't think it has a good chance of success for a good few years after treatment). 

We don't always need all the molars in our head, so the loss of one or two isn't usually a big issue from a functional point of view - but if it hasn't been root filled successfully by the dentist (and however it's dressed up - it hasn't!) Then either get it sorted properly, or extracted.