In my view, its the root canals that are the sources of your problems. As you mentioned, your symptoms began to occur after having the dental work done.
Although you might not feel pain in those teeth, they most likely allow bacteria to proliferate in the necrotic tissue and their toxins can travel anywhere's in the system; ear/sinuses problems and Arthritis are typical symptoms of people with root canals, including other nonspecific symptoms which can be traced back to the meridian connections of each tooth with the organs.