I had a root canal last week and nowmy jaw is swollen and i'm in a lot of pain. xray doesn't show any sign of infection and my dentist sayshe can't do?

Something's Amiss: Was the root canal just started last week, or was it finished? Radiographs don't always show everything... the tooth may have a periodontal pocket, an additional canal, or even a fracture. Infection is always a possibility. If your dentist is stumped, she should refer you to an endodontic specialist and/or an oral surgeon for further care.

See an Endodontist: The key is to have an Endodontist with the diagnostic skills to be able to do a proper diagnosis of your problem. An endodontist is a dentist who has completed a 2 or 3 year specialty program about root canals.

2nd opinion: You may need medication and/or re-treatment. X-rays don't always show everything needed to diagnose your problem. As your Dentist has tried her best but is unable to give you more information, she should refer you to an Endodontist. Root Canal Specialists have 2-3 years more training, limit their practice to just root canal Rx, and have equipment that your GP doesn't have.