As a child, I used to have gas for any drilling, and now have injections. It still doesn't take away the whole feeling, and my old dentist was very good at spotting when it was hurting me, or when I needed to take a swallow, and let me take a moment to take a deep breath before he carries on, and didn't make a fuss about it.
So sad when he retired and I had to use the practice that took over his patients.
What really really hurts me, though, is the high pressure cold water they use to remove plaque - I actually screamed a couple of years ago and pushed the dentist's hand away. She told me (I'm not a kid!) to stop being silly!
So I asked for a different dentist in the practice for the next appointment, and now refuse the plaque removal (I've never had a problem with plaque, and the dentists IMHO just do it to push up their fees)