I think the dentist is a ripoff. For the dental cleaning, I already floss my teeth and use mouthwash once every 6 months. I could easily use the gooey stuff that they put in the mouthguard, and if I need to suck the saliva out of my mouth, I'm sure they could make a vacuum cleaner attachment for that. I could use the metal gum-scrapey thing for the front of my teeth, and have a girlfriend do the back of my teeth where I can't see. And if I didn't have a girlfriend at the time, I could pay a hooker to do it. It would still be cheaper than going to the dentist. Although it might be a bad idea to have a hooker's hands in your mouth when your gums are bleeding.
And they could have a dental inspection kiosk at the grocery store to inspect your teeth. That machine could take both photos and x-rays of your teeth, and those little pieces of paper that you have to bite down on to take the x-rays could be sold in vending machines. Software could analyze the results within a few seconds, and maybe inconclusive results could be emailed to real dentists in India or somewhere cheap within a few minutes, kind of like a tech support call, but to a dentist instead of a computer guy.
Since I have shown that a person, maybe with the help of a friend, can handle the once-per-6-months dental cleaning, and the dental inspection kiosk can handle the dental inspection, you would only have to go to the dentist if you actually had a cavity or a painful tooth or something.