Whether root canal treatment will hurt the second time or not can not be uniformly determined, depending on a variety of factors, including personal physical condition, root canal treatment effect, and physical tolerance. 1. After root canal treatment and then the second treatment, if the patient’s pain nerve is not sensitive, and the recovery after root canal treatment is good, no residual tissue; at the same time the patient’s state of mind is more relaxed, the second treatment is not tense, the pain is generally not strong, and most people can tolerate it. 2. If the first root canal treatment is not good, and there is residual pulp tissue, the patient’s own conditions are not good, the mentality is not good, in the face of the root canal treatment is too tense, anxiety, resulting in pain sensory nerves are too sensitive, it will cause pain, and the pain is relatively strong. If you are worried about pain during the second time of root canal treatment, you can inform the doctor first and decide whether you need to inject anesthetics according to your own condition so as not to affect the treatment.