X-rays show no cavities; the dentist agrees from having looked around a bit. The gums are a little receded, maybe it's sensitivity due to that.
It's also possible that it's related to me grinding my teeth at night; I'm pretty sure I do this, at least a little, and during the day too. I've done it since I had a filling put in that was a little uneven, I think. So it's possibly sore ligaments in the gums.
Nothing drastic, and my dental insurance covered the whole visit. This dentist (Bean recommended Kendall Dental Associates) gave me a good vibe the way no other has before... maybe the way he went out of his way to say he didn't want to drill when it might not be necessary (and really, it looks like it's not at this point.)
Still, this scare might be just enough to get me brushing and flossing religiously again.