You might feel a slight pinch.
Translation: You are about to experience a piercing, penetrating pain in an extremely sensitive area.
You may experience some pressure.
Translation: But you'll definitely feel a very pronounced and prolonged pain- so don't say that I didn't almost warn you.
Those are the inevitable and oft repeated threats I have accustomed myself to after year upon year of: cracks, crowns and fillings, et al. But there's one I haven't quite conquered, the one far back in those reptilian recesses, the one that comes inexorably forward with every succeeding visit- because it could, just could, manifest into reality...
What if THE BIG ONE just happened to hit right when he's plunging in the needle, or powering up the drill as you open up your widest so he can reach all the way back there?
Honestly, I try not to think of such things...