Can this tooth be saved. Number 7 had previous root canal and now abscess may have cracked root?

two years ago had root canal and now abscess, not sure if pero abscess or root problem, is there a way to tell, my dentist is not sure. Is there a test, and will I waste my money running around to experts who will tell me to pull it. I guess I can get retreated and apexectomy or have it pulled and do bridge or implant, but I would rather save the tooth, if possible. there maybe a crack root and bone loss, but no sure, It is having resorption problems and not sure how to get this tooth to behave.