I had a root canal treatment done on a tooth one year ago. it has never settled. recent x-rays show nothing. i have constant dull ache all the time. what should i do?

See dentist: Return to your dentist. Ask for a referral to an endodontist (root canal specialist) or another for a second opinion. You could have a cracked tooth or possibly another canal. Does your tooth feel high? If your bite is off, this could cause a dull ache. A small percentage of root canals do fail for no obvious reason and the teeth need extraction.

Other points: I agree with the excellent points made by dr. Donley. Sometimes a patient cannot pinpoint exactly where the 'dull ache' is coming from. It may be a minute fracture on root, or even another tooth. If a consult with an endodontist still reveals nothing apparent, consider a cbct scan which is a 3-d image which often shows pathology which cannot be visualized clinically or with conventional x-ray.

Lingering pain: If it wasn't done by an endodontist, see one to evaluate. There can be many reasons. Recurrent infection not visible on xray, missed canals, fracture, trauma due to bite issues, etc. Sometimes there is no explanation, and it is like phantom pain after an amputation. The remaining nerve still reacts as if there is nerve in the tooth, can even continue after extraction. There are pain specialists.