Wednesday, July 20, 2005

First Impressions

Until today, I did not appreciate the level of skill and technique required in taking dental impressions. It's a bit like making a soufflé. The process looks straight forward enough (mix alginate, load tray, pop tray into mouth, wait, pop tray out), but your technique and timing have to be just right, or the entire thing just might fail. For soufflés, you won't really know until the very end whether the damn thing will rise gloriously above the ramekin or whether your cursed pastry will deflate at the very end and become a flat, wasted mess of semi-fluffy dough. For dental impressions, the only way to achieve success is to pour the stone and crack the final cast out of the rubbery mold (the initial impression).

Today's assignment was to create 2 impressions of the upper jaw and one impression of the lower jaw. My final tally for today: 0 for 12 for the upper, 1 for 3 for the lower.

The mandibular arch impression (lower jaw) went fine. One for three is about average in my class, as far as I can tell.

But it took twelve tries for me to get a perfect mold of the upper jaw, and even then my instructor had to help me mix the alginate (putty) to get all the air bubbles out. Once it passed her inspection, I poured in the dental stone, worked out the air bubbles and waited for my cast to achieve the final set. Forty minutes later, it was done. With great trepidation, I retrieved my model from the shelf.

Then, I dropped it.

Thankfully, the only part that broke off was a small piece of excess stone from the back. It was definitely salvagable. In fact, there was a pretty good chance my creation would make it through unscathed.

Very carefully, I hammered away the excess stone and popped the cast out of the mold. It was beautiful. I could die a happy man.

Next stop: checking it off with my instructor. She turned it over in her hands, examining the margins and borders.

"That's pretty good," she said. "But what's that?"

Me: "Uh... what?"

That was a huge crack, scarcely the width of half a human hair, running from the back of the throat to the central incisors.

I pleaded, "It's okay, right? I mean, I can still trim it down... it'll hold right?"

"No, once you start getting those extra vibrations from the trimming process, it'll just grow bigger until it falls apart."


0 for 12, mate.

I'm batting worse than pitchers in baseball.

It's a good thing this isn't due until next week.


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