Many thanks to both of you for giving so much informaiton.
Joe, I was reading through your answers and the one thing that stood out was that you have had 3 root canals. I've done a fair bit of research on root canals and ended up having my one root canal tooth pulled out. I feel a lot better since having it removed. I also had another tooth with a crown removed. They were both molars and it was a big decision. The dentist had put Amalgam underneath the porcelain crown.
A lot of your problems may be coming from your root canals. You may want to do some research. I recommend George Meinig ( root canal Cover Up) and all Hal Huggins books.