Back when I was a kid (practically the Stone Age) most dentists didn't use novocaine when filling children's teeth. The belief was as they weren't permanent, and had no real roots, there was no real pain so novocaine wasn't necessary. That's pretty wrong, and with all the silver fillings in my teeth, I can attest to that!
When I was in my late teens I went to a dentist who used gas instead of novocaine. I thought I was in heaven after the experiences of my childhood. Unfortunately this was a guy who did two very deep filings in 2 molars, and did them improperly. They were overfilled and I was in agony once the gas wore off. I actually dug the filling out of one tooth in my sleep that night. Took me 2 visits for him to "get it right" and was at the oral surgeon within a year to have both molars extracted.
My current dentist is a peach, who is amazing at pain control (to be fair, a lot more is known about dentistry now than in the 1960s). My theory of dentistry is that I should be numb pretty much from the belly button on up, and he laughs with me but pretty much agrees that there should be no pain associated with dentistry. Unfortunately the psychological trauma of my childhood is strong, and I absolutely HATE to go (and consequently don't go very often). Luckily, I have decent teeth and take good care of them, so fortunately I haven't had many serious issues arise.