I'm not fond of going to the dentist but I go every 6 months. I had all my crowns put in during the 90's while I was still in the US. $$$$ even with dental insurance. My dentist was great about getting me high on nitrous oxide even before the novacaine as I'm a wuss. Glad I don't need anything now as you can't get the option of nitrous. There has be to an anesthesiologist to adminster it, not just the dentist.
I had gas last time I had a tooth pulled (about 4 months ago). I don't know what kind of gas, but just the technician administered it. It made me feel worse than the last time before that, which was more than 40 years ago, so maybe it was a different gas this last time. I've never been to a dentist who has a special anesthesiologist. Hmm .... maybe I better look for a different dentist!
A lot of tooth and mouth health is hereditary. My parents both went to the same dentist regularly. My dad never had a cavity, never had a tooth break 'til he was up in his 80s. My mother had root canals and crowns from maybe mid-40s on. Same dentist, same care, same good dental practices; different teeth and gums.