Don't rework your already failed root canals. I had 4 root canaled teeth worked on again and again and again. 4 years later i finally had the last of the 4 extracted.
guess what these million dollar teeth were filled with....
tons and tons of infection..in the roots and the surrounding bone.
i too became systemically ill with debilitating fatigue, pain and weakness from all of these rotten teeth sitting in my mouth for all these years.
i went to 2 of the "best" endodontists in sf to have these teeth worked on. what i've learned from this disaster is that some of us with overburdened immune systems cannot support these "infected" rc'd teeth.
don't spend another dime trying to save these teeth while destroying your health. find a good dental surgeon who understands that focal teeth infections can make you sick and that constant reworking of root canals ccannot rid you of these infections.