I had a bunch dental of work done all in one month when i was a kid; i built up a tolerance to Novocaine and for the last two visits it had no effect. Teeth pulled wasn't that bad; or at least it was over quick.
The 4 fillings were a trial. i broke the arm off their chair trying to hold still for that. Driving home afterwards stands in my memory, to this day decades later, as the stupidest i've ever been on the road. Miracle i didnt kill anyone.
It changed my relationship to pain and how i processed it. And kept me away from dentists 'til it was time for dentures.
I've had a few fillings without anesthetic. My dentist told me that most of the pain of drilling is because the drill bit and tooth heat up through friction. Modern drills have water cooling and don't heat up at all. So for shallow fillings there is no pain.
My two root canal procedures did have local anesthetic though. Didn't hurt either.
Had several fillings but never had an anaesthetic for any of them, only for a tooth removal. It wasn't even suggested, though I could have asked for it I guess.
Seems to me that the pain of the anaesthetic needle and the numbness would be worse than the drill.
I have pain feeling sometimes even with anestetic, so I always choose to use it it when the doctor asks.