I'm sorry I'm going to say something controversial here but this is something that I have come across during years of battling RA that I think I'll just point out what I read and what I know.
There is actually a tooth/gum connection with RA. While studies often show that people with RA may be up to 4 times more likely to have gum diseases than people without autoimmune, the biology of this association becomes unclear. There are some who believe that it is gum disease that cause the chronic inflammation in RA. Our mouth and our gum is a mucosa/pathway through which bacteria can enter into our bloodstream and basically anywhere in our body.
Root canals on the other hand may resolve many issues of tooth pain but an absence of pain does not equate to a good oral health, but merely a result of nerves being removed. Irregardless of the due diligence put into disinfecting the infected cavity, a root canalled tooth will always remain infected. The very nature of the tooth does not allow complete sterilization while it still resides in the mouth.
Bacteria that lives in your mouth and that has gotten locked into these cavities mutates from an oxygen-loving form (aerobic) to one that does not love oxygen (anaerobic), and build a impenetrable bacterial fortress where they live and thrive.
At the same time, the bacteria expel toxins, waste products that are detrimental to the surrounding tissues and general health. Where they can avoid the arrest of white blood cells by hiding in areas where blood supply is restricted and immune response is slow, it starts building colony in our joints! (because joints do not have blood supply like other tissues of the body). This fort makes the root canalled tooth a breeding ground because it no longer has a blood supply and hence, neither white blood cells nor antibiotics can enter.
Very often, onset of RA often surfaces after a stressful event in a person's life, and if our health is compromised and our immune system is incapable of completely contain the infection in a root canalled tooth, there will be an increased risk of systematic involvement.
Having said these, I suggest anyone with RA to approach a biological dentist from www.IAOMT.org
and read more on this from Dr Weston Price Foundation website
Rheumatoid Arthritis & Hypothyroidism, 2 years+, believing in healing the natural way.www.myradiary.com