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labdude
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As this is a copy of an e-mail, and I'm to lazy to put the message first, you have to sort it out. Read the "original message" first.
Easy one. Just to much acrylic. It is true that different acrylics from different makers do behave differently, that is to say, they differ.
Watch this video again. http://dentallabnetwork.com/forums/f42/s-p-spring-aligner-regular-lower-video-2162/
At about the 3:50 minute point I adjust the camera for a better view. Still, I see the detail is missing quite a bit for what your asking about. I need to try and get a better focus or something, maybe zoom in closer. Anyhow, watch the video, you can see in certain parts of the pink lower work, the wire is still visible through the acrylic. Use the pause a lot.
Answer is, put on less acrylic to avoid the slumping. Better to thin than to thick. If it is to thin, you can add to it after it is cured, before removal from the model. Make sure the moisture is dried of it first, just wipe it with a paper towel. Temperature is a factor, even with the AC doing a good job in the summer, I have to work a little faster. These colder months, the acrylic supply stays cooler, allows more time. Slightly anyhow. Temp is not your problem, volume is. I think I mention somewhere in the posts to keep the acrylic only 2 times as thick as the wire, no more than 1 thickness of wire under wire. Meaning....Lay on the S&P no more than 2 times the thickness of the wire, over the wire. And keep the wires as close as you can to the model by making them no more thean the thickness of the wire used, off the model. .030 wire should have .030 clearence under it, no more or acrylic gets to thick and slumping problems happen. As well as patient comfort goes in the can if the acrylic is to thick. I don't anymore, but used to, carve rugae in the palates so a patient wouldn't lisp when talking. This is done in dentures, so why not here, I thought. It did work well, drs liked it, patients liked it. But nobody really cared enough to keep doing it. It is an extra few minutes of work per case, that adds up quick.
Mike.
Yup....gonna copy this and put it over on DLN too.
----- Original Message -----
From: Ron Shubin
To: [email protected]
Sent: Tuesday, January 13, 2009 10:02 PM
Subject: Diagnosis
Mike,
Tonight I decided to just make an upper hawley wrap (Rachels own model) start to finish and the wire came out ok. Next I did the S&P and seemed to go on pretty smooth about 4 layers and to the pressure pot for about 10 minutes at 20 psi with luke warm water. Opened it up and found that the acrylic had slumped down and some ran off the model. What did I do wrong? The acrylic is from GL and it is the tropical green color if your familiar with that one. It was going pretty smooth until then.
Just thought of something that could be a factor, I did the wire bending in the house and then went out to the lab to do the acrylic work and it's pretty cold out there probably 45 or 50 degrees. When we start using it regularly we'll keep it warmed up.
Thanks
Ron
Easy one. Just to much acrylic. It is true that different acrylics from different makers do behave differently, that is to say, they differ.
Watch this video again. http://dentallabnetwork.com/forums/f42/s-p-spring-aligner-regular-lower-video-2162/
At about the 3:50 minute point I adjust the camera for a better view. Still, I see the detail is missing quite a bit for what your asking about. I need to try and get a better focus or something, maybe zoom in closer. Anyhow, watch the video, you can see in certain parts of the pink lower work, the wire is still visible through the acrylic. Use the pause a lot.
Answer is, put on less acrylic to avoid the slumping. Better to thin than to thick. If it is to thin, you can add to it after it is cured, before removal from the model. Make sure the moisture is dried of it first, just wipe it with a paper towel. Temperature is a factor, even with the AC doing a good job in the summer, I have to work a little faster. These colder months, the acrylic supply stays cooler, allows more time. Slightly anyhow. Temp is not your problem, volume is. I think I mention somewhere in the posts to keep the acrylic only 2 times as thick as the wire, no more than 1 thickness of wire under wire. Meaning....Lay on the S&P no more than 2 times the thickness of the wire, over the wire. And keep the wires as close as you can to the model by making them no more thean the thickness of the wire used, off the model. .030 wire should have .030 clearence under it, no more or acrylic gets to thick and slumping problems happen. As well as patient comfort goes in the can if the acrylic is to thick. I don't anymore, but used to, carve rugae in the palates so a patient wouldn't lisp when talking. This is done in dentures, so why not here, I thought. It did work well, drs liked it, patients liked it. But nobody really cared enough to keep doing it. It is an extra few minutes of work per case, that adds up quick.
Mike.
Yup....gonna copy this and put it over on DLN too.
----- Original Message -----
From: Ron Shubin
To: [email protected]
Sent: Tuesday, January 13, 2009 10:02 PM
Subject: Diagnosis
Mike,
Tonight I decided to just make an upper hawley wrap (Rachels own model) start to finish and the wire came out ok. Next I did the S&P and seemed to go on pretty smooth about 4 layers and to the pressure pot for about 10 minutes at 20 psi with luke warm water. Opened it up and found that the acrylic had slumped down and some ran off the model. What did I do wrong? The acrylic is from GL and it is the tropical green color if your familiar with that one. It was going pretty smooth until then.
Just thought of something that could be a factor, I did the wire bending in the house and then went out to the lab to do the acrylic work and it's pretty cold out there probably 45 or 50 degrees. When we start using it regularly we'll keep it warmed up.
Thanks
Ron
