I recently went to dentist because my 5 year old crown fell out. They did x-rays and saw that I have an infection. So they referred me to an endodontist to perform a root canal. 2 different doctors attempted to perform the root canal but was unsuccessful. Both of them said that they could not remove the post build up material from my canals from a root canal that was done 5 years ago, so they said that I have to have the tooth extracted. Should I go to another dental office for another opinion or is this typical for an endodontist to have a difficult time removing this material to proceed with root canal treatment. I really want to save this tooth. Can you please help me? Thanks!