Monthly Archives: November 2007

I almost put this under the title “Tricks of the Trade – Alginate Over Impression.”  Every once in a while you see some work that brings a tear to your eye. A couple of weeks ago one such occasion occurred. My good friend from undergraduate and I are in the same class and we are next to each other in the alphabetical list so he also sits next to me in pre-clinic. He made the most beautiful 3-unit bridge. This unit, as seen in the picture, replaces teeth 9 (left central incisor abutment), 10 (missing left lateral pontic), and 11 (1st premolar abutment). We prepared the teeth in a previous practical and then the next week we had a practical to make this provisional.

The method was quite simple. An alginate impression was taken before the practical and kept moist while the teeth had Vaseline smeared on them and the jet acrylic was mixed. The alginate impression was used for the over impression. Acrylic was placed inside the impression and placed back onto the prepared teeth. I like to use alginate as an overimpression because:

1. It is inexpensive (compare to mach slo, etc) and you save yourself quite a bit of money.
2. The alginate impression is moist and allows the acrylic to set up a little quicker. Jet takes a while and during a practical, time is ‘money’.
3. It is quick (see #2)
4. Alginate is accurate. It gives great results as you can see in the following pictures.

I asked my friend how in the world he came up with great results (we used the same method), and he told me, “Sometimes things just fall into place.” How true is that. Without further boring you with more words, lets see the pictures:

For a DETAILED view, you must click on the picture. It enlarges it. Everything is perfect in this bridge. That’s what I call falling into place! Good job Class of 2010!

We learned early in our first semester that turning in a dirty typodont after a practical might receive a check. The grading forms don’t have a section under cleanliness so no one really thought to clean the mouth. Some people got their grading form back, freshly revised & edited, with a ‘written in’ requirement and a check next to the mysterious appearing mandate. Ever wonder why dentists are anal retentive sometimes? I think it goes back to our training. 1mm is VERY different than 2mm and in the case of this article: Shinier is better! As doe-eyed D1 students we learned quickly to clean our typodonts of all dust, wax and stains.

Yet it has taken me quite some time to figure out the best way to clean off that red/blue stain of articulating paper from ivorine teeth. We equilibrate our typodonts periodically to make sure that there is no rock in the occlusion, that every supporting cusp fits snugly into the opposing arch’s central groove, and that there are no lateral interferences. This leaves our teeth just rough enough to get a little bit of this articulating paper color stuck into small micro grooves and it discolors the teeth.

The solution: Robinson Bristle Brush followed by some rubbing alcohol. In the past I would just use rubbing alcohol, but it wouldn’t get in the grooves. The Robinson brush does the trick. Make sure you use it on a lower speed without generating much heat. Hopefully this trick helps you tremendously. I found out about it two weeks ago and mentioned it to a classmate of mine tonight. After he tried it in the lab and he was thrilled. (Only a dental student would appreciate such a simple pleasure as clean ivorine) He hadn’t heard of this trick yet. For those of you who already knew about it and have been holding out on us, I have one question: “Whats the deal?”

You can also brush up the typodont gingiva under the acraluster wheel. It brings back the shine and we all know: The shinier, the better!