###Human: Is my toothache during root canal treatment due to calcium hydroxide allergy? ###Assistant: Hi. I had gone through your question I can understand your concern. The pain may be because of post RCT infection or because of the accessory canal in the root that becomes sometimes difficult to manage. In case it in infection you need to take antibiotics and that will help you. If you had antibiotics and pain still persist, please let me know about the name of antibiotics because you may be resistant to it. You can also upload the pictures of X-ray done during root canal treatment so that I can tell you, if RCT is done properly or not. An allergic reaction does not precipitate in the form of pain only there could be certain associated complications too.