No. It is not possible to determine if root canal therapy was properly done or not by the pain. The radio-graphic image will help the professional determine if the treatment was successful. A root canal is “well done” when this radio-graphic image shows a high probability of the tissues surrounding the dental piece remaining healthy, or healing in case they were damaged. The post-treatment pain is a consequence of the inflammation of the tissues that surround the point of the tooth root, which is generated by the instrumentation of the root canals, the liquids used, etc. This pain is intensified with pressure, and it can get very strong. If the pain is very strong, you should contact your dentist.