I have been having issues with tooth #13 for over 3 years. We did an inlay for a large cavity. Then a root canal. Then an apico. The tooth felt a bit better after the apico but never completely (that was 2 years ago). Now the tooth is really hurting again. My dentist thinks there is a second canal that was never treated. My Endo says there is only one canal and is recommending extraction. Any tips or advice would be appreciated. X-ray is attached.