Personal experience is when I began to replace essential fatty acids from seed oils with the EFAs from animal fat, my attempt to heal showed some success, so I believe this to be fundamental to what you are trying to do.
Reason why is that permeability of cell walls is determined by their composition, and the membrane is made of EFAs.
If the body is starved of animal fats, it will make cell walls of veggy fats, and they are wrong.
I use mostly butter, for lack of better. It is working.
I had similar experience with dental work, at about the same age except thankfully no root canal. Half the teeth remain, all with plastic composite fillings. NO metal in my mouth.