Yo, I had a similar thing happen with a tooth. Did a root canal, thought they got it. Turned out that the tooth had a short root and cracked after it was filled. Now that I think about it, this happened to my dad more recently too.
Anyway, it sucks that one of the most expensive things I own is a little piece of my head. That said, walking around for almost a year with no tooth is a humbling experience, even if wasn't noticeable. I found that it was also great for keeping me mindful of my own suffering in relation to that of others.