When I was a lad, going to the dentist was really scary and painful. Now, I don't find it a problem. They don't use gas any more here and my dentist's X-ray machines are really quite something. You just put a small plate in your mouth and the X-ray is shown immediately on a large computer monitor. No problem with injections - I suspect that I'm lucky to have found such a good dentist.
Virtually no NHS round here (and even less in S.England) so I've always had private dental insurance. For a fixed fee, I get two checkups incl. any X-rays, and two hygenist visits every year. Any other treatment is at a reduced cost.
I was very lucky to get into the one NHS dentist here. I think they have 3 dentists and a hygienist.
The one time I needed novocaine it was almost painless. The dentist said he learned how to do it in dental school by practicing on each other. He pushed the plunger very, very slowly. Most dentists do it too fast which is why it hurts.