Root canal treatment is a very successful treatment when performed to a high standard. However, it is important to remember that it is impossible to guarantee the success of any medical procedure. Even with the very best treatment, healing may not occur due to circumstances beyond the control of the clinician. For teeth without an abscess or an established infection, root canal treatment enjoys a very high rate of success (90%-95% survival at 10-15 years). Once a tooth has become infected the success rate can diminish with the increasing size of the abscess. Success in these cases could be quoted at 70%-85% survival at 10-15 years.

Re-treatments (doing a root canal treatment for a second time) have a slightly lower success rate, however 80% is a reasonable expectation.