Thank you for your question. I'll do my best to answer it for you.
There are a number of causes of pain after the completion of a root canal treatment. After a root canal is completed although no living pulp tissue remains inside the tooth, but nerve endings remain in the ligaments that attach the tooth to the surrounding bone. These ligaments have nerve fiber associated with them that can feel pain. They are the source of pain after a root canal treatment.
One of the main cause of pain is inflammation of the periapical tissues post root canal. This inflammation may be due to extruded sealer during the root canal therapy or over instrumentation during the endodontic procedure. Sometimes the root canal files go past the apical terminus and can either inject some debris periapically or just damage the ligaments. This inflammation usually resolves by itself given enough time.

Another source of pain is a high bite and this can easily be corrected by your dentist. If a patient bites down, with no food in their mouth and their root canaled tooth hurts, then the bite should be adjusted. Teeth undergoing root canals should be not be in a heavy occlusion and it can lead to pain likely to your case.

Also pain can be because of a persistent infection or a root fracture. If a root canal is completed, but an infection still is present around the periapical area then a retreatment may be indicated especially if significant time has gone by without a resolution of the infection. Sometimes an infection can be caused by a fracture of the tooth in question and in that case the tooth.
By the way as a dentist specialized in prosthodontics, I recommend you to wait a couple of days (up to 14 days) and if you still feeling pain or discomfort visit your dentist and ask for retreatment but I think pain will soon over.

I hope you get well soon.

If you have any more questions, I am happy to help as much as possible so feel free to ask.

Thank you for your question,

I recommend you to wait for almost 1 more month, if your pain get worse or you have any sign of inflammation such as fever, I highly recommend you to ask your dentist to redo the root canal therapy but if it is mild pain, it can be normal.

In case of root canal failure, re-root canal treatment, Apicoectomy or tooth extraction may also be required to remove the infection from the tooth.

by the way If the treatment has failed, the dentist will evaluate the condition of the tooth and the reasons of the root canal complications, in order to decide if the tooth can be saved.
Unfortunately, in some cases of failure the tooth can not be saved and it has to be extracted. A bridge, implant or a partial denture has to replace the lost tooth.

I hope you get well soon.

If you have any more questions, I am happy to help as much as possible so feel free to ask.

Thank you for your question

most of the time tooth pain and tenderness or swelling of the gums in the area of treated tooth and in other cases, problems such as a new infection can develop without any symptoms.

no it is not normal

sensitiveness cause usually is a exposed dentine. a dentine contains little tunnels that link to the nerves on the inside of the tooth, and when dentine is exposed, these nerves are easily stimulated, resulting in pain.

but at the case of root canal therapy, the tooth can be sensitive for some days or even 1 month

I hope you get well soon.

If you have any more questions, I am happy to help as much as possible so feel free to ask.

by the way follow up visit after root canal therapy and x-rays are very important in determining the success or possible complication of a it. X-rays will help us to detect any sign of inflammation in or around the tooth that could indicate root canal complications.

Thank you for your question

it is different in each individual

sometimes the tooth is sensitive for more than 1 month

but usually it take less

so it can be different in each individual

If you have any more questions, I am happy to help as much as possible so feel free to ask.

Thank you for your question

Slight pain or sensitiveness can not be the reason for a retreatment

on the base of your complaints I recommend you to wait for couple of days or some weeks

your bite has been changed

and it needs the adaptation

antagonist teeth are under the stress

and the extra pressure and retained defect of surrounding tissue will be gone in couple of weeks

As a prosthodontist, I suggest you to be more patient about your teeth

I am quite sure it will gone

had many similar cases that never call me back after adaptation of teeth and oral tissue

I think the border for redo a crown is a permanent pain and a defect in the crown ,antagonist tooth or surrounding tissue of root under X-ray

I hope my answer is useful and informative to you.

If you have any more questions, I am happy to help as much as possible so feel free to ask.