When the dentist hooks you up to the mask and the tank of N2O, does she mix it with O2 and/or ambient air, or are you just getting pure N2O?
It’s a mix, usually 50/50 of N2O and O2. Pure nitrous oxide would kill you.
Yeah, nitrous oxide doesn’t provide you with any oxygen to keep you alive, so you would suffocate.
There’s a gauge on the machine that tells them how much % of nitrous to oxygen you are getting, and they can turn it up or down. Since pure N2O would kill you, I suspect the machine doesn’t let them go all the way to 100%.
The last time I had nitrous I think they went up to 70% before they believed me that nitrous doesn’t do anything for me, and just went on with the procedure.
So she has a tank of N2O and a tank of O2 and mixes them together?
Yeah, that’s what I thought.
I first started getting nitrous about 1973. The dentist was on an upper floor in an office building. I remember leaving one session when I found myself at the water fountain halfway down the hallway without remembering how I got there. Then I was at the elevator without any interval. Fortunately, hitting the open air cleared my head completely.
My current dentist told me that they used a lot less of a mixture in those days. (Actually, he said that they didn’t use any mixture. That contradicts what’s been said here. Since nitrous parties go back to its discovery in the early 19th century when they breathed the stuff to get high without any oxygen mix small doses might not be that deadly.) Today’s levels are optimized to need less recovery.
I can testify that there is a huge difference between the way I felt then and the way I feel now during a session.
My dentist gives me a shot of oxygen after he turns off the nitrous, which clears my head almost immediately.
Nitrous Oxide doesn’t actually kill you itself, the way you die is from lack of O2. That is why dentists use a mixture in order to supply enough O2 to keep you alive (atmospheric O2 is 28%).
Here’s a page with a few pictures and short explanations about Nitrous Oxide Machines. Click on the pictures on that page to see them full size.
You mean 21%, right?
Yea, that’s what I mean…
Guess that’s why I’m in pharmacy school, not in meteorological school
Technically speaking, yes, it’s an asphyxiant, not a poison (unlike, say, carbon monoxide). But to say that it doesn’t kill you (“it’s the lack of O2”) is like saying that drowning doesn’t kill you.
In the UK where it’s an option for women in childbirth it’s called “gas and air”.
I can remember being given enough nitrous back in the early 70s to make me hallucinate - everything looked like a cartoon [solid flat colors and everything had black outlines, like a coloring book] and sounds did a funky sort of reverb like the keyboard section of Baba Oreiley. Very strange …
Yes, yes, yes to the sounds, though I never got the visual effects. I always thought of it as having the sounds swirling down a drain. They seemed to repeat themselves several times while being swallowed. Kept up for the entire procedure.
Never happens now.
I’ve experienced the sounds, too, particularly when I’ve [del]done whippits[/del] accidentally misused N2O cartridges intended for culinary use. I believe the scientific term is phlanging (not sure on the spelling).
I can remember getting laughing gas from my dentist when I was kid! I remember staring at the ceiling and hearing Song Sung Blue by Neil Diamond. But it was the best damned song I’d ever heard. I didn’t really see anything other than the ceiling panels seemed to be Right. There.
Probably set the stage for the long strange trip it’s been since then… 
My first experience with nitrous was in the mid 70’s. I remember feeling calm and peaceful. The dentist had earphones to pipe in music that simply filled my head…then came the drill. The drill was a bit of a buzzkill and I was mightly annoyed so they upped the dose.
Good times, good times.