Does the second visit to having a root canal filled require numbing or is it painful afterwards?

Maybe Numbing: Not sure why your procedure had to be completed in 2-steps; however, usually the second step is relatively simple in nature. The 'difficult' part is done in the initial visit, if you doing a 2-visit procedure. That said, numbing may be necessary; soreness afterward, most probably none.

Most likely: A root canal requires one or more office visits and anesthesia may not be necessary, since the nerve is dead. However, most dentists still anesthetize the area to make the patient more relaxed and at ease.Good luck!