I have RSD in both hands and both feet .... had a root canal about 6 months ago and all went well. I understand your concern, I was scared too but didn't want to lose the tooth. Now I'm due for some more extensive dentistry..scaling and a couple back teeth removed.
I brought some information to my dentist about RSD so they could put it in my file. It's frustrating, every time I go and see a new dental specialist I have to explain it all over again but it's worth it, they numb me real good.
Good luck...hope this helped some to put you at ease
Jeanne