Root canals. They aren't fun though this one wasn't nearly as bad as the first one I had 30 years ago. That one really wasn't pleasant. This one was mostly marked by having to hold my mouth open for nearly an hour and being unable to swallow, beginning to thing about having to cough but knowing that wasn't going to have a good end to it. The tooth was dead. Sadly. I wish I had pictures to post of the process. You'd all love it.