I'd always expected a root canal to hurt, having heard it so often used as a superlative event in the discussion of pain.
While not a walk in the park, I think it pales in comparison to the reason for it in the first place. In my case work isn't actually finished yet - just the emergency prep work. The rest of it will be completed in a week or so, after the medication has a chance to do its stuff.
Whereupon I reserve the right to adjust this statement to incorporate new experiential data.