I had a root canal once, and the dentist couldn't get me numb enough. He filled things back in and referred me to a specialist. The specialist cut open the to

I had a root canal once, and the dentist couldn't get me numb enough. He filled things back in and referred me to a specialist. The specialist cut open the top of the tooth and stuck a needle directly into each root of the tooth... that got me numb. It was a completely painless experience.