Hello, it's bean a while since I posted on DNL forum so please excuse my English and spelling
@ Avi
The quickest way to produce clear aligners is, as Orthodent described, by pressure or vacuum forming over plaster model.
The problem with this technique is that you can make one aligner per plaster model. You could even make 3 aligners with one model for simple cases. After the first set of aligners the doctor has to take new set of impressions to make new set of aligners. Repeating the same process counts as time spent on same case.
I started using 3D toys a couple months ago and believe me - the level of precision and tooth movement predictability is way over the human ability.
"Eyeballing" is slower when compared to 3D technique because with this technology you can make like 20 or more aligners at once. Try making more than 3 aligners by hand, or try making 10 or 20 by hand, no way your "eyeballing" will be precise enough.
Scanning, processing and printing 3D models seams to take more time but when you're done you sell more aligners at one "hit" + "spicier" aligner price
@ Orthodent
Align Technologies has patents for some stages of this process, but not all. If you "google" enough you will find that there are many companies all over the world with similar product. There's Clear Correct, Nu Braces in USA, Clear Step in UK. There's a lab in Egypt, Indonesia, S.Korea. Couple of labs in Germany... and so on.
Align is very aggressive in trying to keep this technology for them selves, but I think you can produce aligners freely if you stay "below the radar".
As I know the Align will "go for your head" if you try to use client-based software to communicate with doctors, and you can't officially market more than 5 tray aligner product at once.
I hope I answered some of your questions