I have also had a root canal done which resulted in that tooth receiving a full crown (ouch on the cost too), and I assume you have had the tooth sealed up somehow, say a crown. You didn't say.
I would see my primary care first, to the degree I understand your problem... clearly you need get a medical check.
Also, my case, I get a tooth cleaning and check up every 6 months, or thereabout, so it I was due for that I might see the dentist first, just a practical point, not a reversal on my first suggestion.
Good luck, hope you get an easy and quick fix.
Jerry, thank you for your response. No, I never had the crown put on. Insurance wouldn't cover it and I couldn't afford it.
Yeah, I think I'll try my primary care first. It's still bothering me but not as often.