"one stuck her fingers in my mouth so she could hold the sucker in place till it hardened" Yeah.... that's how it's done. If I don't hold it in place, it won't be even and we'll have to do it again. Oh and... bite me and we'll have "words".

Be that as it may, I am sure that there are better ways to get a good mold than holding a kid down and putting them in considerable pain. I had impressions taken again towards the end of my cosmetic dentistry ordeal, and then they just had me bite down on the mold to keep everything even. Not pleasant, but not dehumanizing hell either.

Yes, but that's a different type of impression material in a different type of tray.

So then why not use that stuff all the time? Or, if it is unsuitable for certain types of moulds, then why not have the individual hold it in place? I mean, I didn't bite, but it stands to reason that other, less scrupulous patients might have a go at it, and jaw strength is nothing to sneer at.

Alginate is relatively inexpensive and has a much shorter set time - about a minute vs 5 using PVS. PVS is used when getting a crown, because it has better "integrity" - it will hold its shape far longer than alginate, and is a more exact impression. Biting isn't an option though. A lot of people bite inadvertently and are apologetic when it's pointed out. If someone were to bite me on purpose, that could be a form of assault. I need my hands/fingers to do my job.

The biting reference in my first post was more of a joke. Obviously, as an adult, I'm much more tolerant where discomfort is concerned and to bite someone would just be asinine. Case in point, I don't bite my dentist even when the process of cleaning hurts like none other. On the other hand, however, I wouldn't put it past a younger child to bite. My mother, an ENT, has told numerous stories about almost getting chomped by an out-of-control kid while doing such things as checking their tonsils.

Also, as far as the materials go, you gave me two types with differing properties but didn't inform me as to which is the one that you think needs to be held in place, or give a valid reason why not to instruct the patient how to hold it in (admittedly there could be a whole magical process to it that I don't understand, but at the moment it seems not beyond the bounds of reasonable behavior so the person doesn't have to be in pain. Discomfort perhaps, but not pain.)

If your cleanings hurt, you can ask for freezing. :-) The OP was talking about alginate, which is the goopy more wet material , and is always in a tray that needs to be held in place. PVS is the more rubbery material - and is usually coloured (purple green, brownish, etc) It can be used in either type of tray - one called a triple tray which had material on both sides and the patient bites it himself. Or it can be used in a similar tray to the alginate which is loaded on one side only (top or bottom) and must be held by the assistant or the dentist. It needs to be held so it doesn't shift around, which would ruin the impression. The other advantage is the assistant can tilt your head forward so the material doesn't ooze down the back - and talk you through it if you start to feel yourself gagging. I know you wouldn't bite - but it's been mentioned (along with hitting/punching) several times throughout this thread.

and.... it shouldn't hurt. If it does, the tray might be the wrong shape for your mouth. The assistant should try it in your mouth before loading the goop. If it doesn't feel right, she can get another one - or modify it with wax to lengthen/soften the edges.

Heh, all this information has confirmed something I suspected for a long time: I had some very unkind/incompetent hygienists/techs/whoevers for those first moulds. When they were doing it, they pushed the thing up hard enough that my head was tilted backwards, which pretty much sucked, as you can imagine. As for what they were casting with, it was probably the alginate, given the description you gave, though I just remember it smelling and looking like plaster. As for it hurting, that was probably exacerbated by the fact that when my impressions were first taken I had a highly arched palate and there was probably no mould on earth that would have fit right. Later, when I had other impressions done, it wasn't half so bad.

unrelated, but having a high and soft palate is actually really good for singing because it lets the sound resonate more (or something). have you ever tried singing lessons?