I had my first - and last - root canal one year ago. Since I've had it I have had strange odors on my skin. No doctors can figure out why, but I always have pain in my tooth when it happens. I know it is the root canal. I know there is something wrong with it. No one can see it, not even on x-ray, but there's too much evidence to deny a connection. So basically, this oral problem has become a systemic one. I personally do not feel they are safe. I would never ever have one again for any reason.
Dear Heartygirl, These are interesting questions. First, I do not know anything about the book you are quoting from. I would suggest very strongly that you research who the author or authors are and their qualifications. I have been practicing my profession for 38 years. I would be amiss to tell you that every root canal therapy is successful. But overall the success rate is outstanding. Certainly how the RCT is done contributes to the success. The body plays a part in the healing process if the pulp tissue is infected. It is also very important how and when the tooth is restored after the RCT is done. RCT is a safe procedure. Any infection should be treated as soon as possible to prevent further complications. Antibiotic therapy is often used in conjunction with the RCT.