It doesn't come accross as vanity at all. I think maybe that you have been waiting so long for the dental work that when you have finally had it done its brought a lot of stress back to you, that maybe you haven't felt in a while.
I think this will probably pass in a day or so. I guess the dental work was just a reminder. Now that it is done though you have some closure and can move forward from it!
"The Optimist sees the rose and not its thorns; the pessimist stares at the thorns, oblivious of the rose."
"Life isn't about waiting for the storm to pass, its about learning to dance in the rain"