Are these root canals proper/ideal?

[Lovinglife]

My new dentist says that these root canals I had done are not ideal and might have to be redone because they are causing me pain when I eat hot foods. What do you guys think? And btw, I have had around 6 root canals done and only had a crown on 1 of them. Is it absolutely necessary to put a crown on after a root canal? And do you think that is what is causing the pain? Not having the crown? To redo a root canal they are asking for $1100. I can't afford that at the moment. Thank you.



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