A lot of stone after processing..

Trey

Trey

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I need more help! After processing there is a lot of stone stuck to the denture. It seems like I am picking it away for an hour. What am I doing wrong?

We don't have a shell blaster yet. I use Liqui-Foil tinfoil substitute to separate and I use Gibraltar Lab Stone (yellow/buff) for flasking.

It gets stuck around the teeth heavily and sometimes sticks to acrylic.

Thanks in advance.
 
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Ron.Ferland

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Here is my technique:

Boil just long enough to just soften the wax. Do not want the wax super molten, as it will seep into the stone, making the separator irrelevant. Boil out and use good old Borax to clean. Rinse with clean water. While the stone is still ultra-hot, pour in some of the separator that Ivoclar sells. Cover everything and then rinse off with a small stream of water. Do this with each flask half; no more than two flasks at a time. Hit them with a second coat of separator, rinse again and sit on the heals. The stone, when dry and cool should look like it has a coat of dry, clear nail polish. This should allow you a very clean outcome.
 
lcmlabforum

lcmlabforum

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Don't forget that a clean, smooth wax up always help. Spend the time to carve and smoothen those areas with your
PKT instruments like the Hollenback, and life easier when you deflask and polish. Making sure you do not have bubbles
around those areas help too when you invest, just a regular paint brush to paint your mix of investment into those areas helps.
Did not know about Borax but some would paint the Ivocap separator over only the stone areas and avoid the teeth,
even though it may not actually stick to the teeth, just a lot easier than having to drill again or clean any amount
pooling in the diatorics.
LCM
 
Trey

Trey

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Here is my technique:

Boil just long enough to just soften the wax. Do not want the wax super molten, as it will seep into the stone, making the separator irrelevant. Boil out and use good old Borax to clean. Rinse with clean water. While the stone is still ultra-hot, pour in some of the separator that Ivoclar sells. Cover everything and then rinse off with a small stream of water. Do this with each flask half; no more than two flasks at a time. Hit them with a second coat of separator, rinse again and sit on the heals. The stone, when dry and cool should look like it has a coat of dry, clear nail polish. This should allow you a very clean outcome.
How do you avoid the separator from getting on the teeth?
 
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MasterCeramist

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You can also use a lab putty during flasking and you won't have to worry about using separator around the teeth and the denture will come out very clean.
 
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Ron.Ferland

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How do you avoid the separator from getting on the teeth?
I rinse the separator off with a small stream of water. Also, forgot to say I use some cold cure monomer on the teeth. I also inject with Ivocap. This in itself allows for greater bond, due to the increased monomer content in the acrylic mix.
 
lcmlabforum

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Yes, and get a good brush that would not leave loose brush strands inside the investments.
LCM
 
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I would use lab putty, or in the good old days of a rubber separator (?),now Densulate whiich is not as good, only in select cases.
Which brings back the situation about using Plaster on all 3 layers in another recent post. The key about vertical dimension
is not just closing flask carefully, and not leaving too thick a flash, we would use a 50/50 mix of stone and plaster
on the middle layer (or that one surrounding the wax up and teeth),but wipe the top of that layer so the cusp
tips of the teeth are exposed. Then the final layer is in 100% Type III stone to make sure they do not shift.
Not as easy to do with putty and expect no changes/teeth shifting. If we used Dentsulate or the old rubber separating
medium has to be thin to avoid dimensional changes during processing and teeth may shift too much.
Just my training, not scientific or anything measured.
LCM
 
ter01475

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The separator will be displaced by the acrylic when you pack or inject...if separator on the teeth makes you nervous, take a Q tip with some monomer and clean off the teeth...same as a bonding agent
 
Affinity

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use putty! picking stone out of teeth SUCKS! make sure cusp tips are exposed to touch stone.
 
JohnWilson

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Every single post is correct.

Ron posted our EXACT protocol which works every time. If you let the wax get to a liquid state your model stone density will determine how much things stick.

If you vac mix your flasking stone and use a flow stone the density of the stone is harder leaving less porous area to get clogged with wax. We use dawn and sprinkle borax when we clean in a boilout tank that recirculates clean water from the bottom of the tank.

If you are compression packing the consistency of you resin can also determine what happens to the separator. If you pack past the snap stage or when your acrylic is super soft you can have issues. The number one thing to do is read understand and follow the recommendation of the resin you are using. So often techs feel they have been doing it "their" way forever that they neglect to consult the instructions.
 
kcdt

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How do you avoid the separator from getting on the teeth?
A paintbrush and care. Don't just pour it in. Apply it in coats.
Paint a hot flask, but wait until it stops steaming. That will avoid having the separator peel away in a skin when you're packing.
DON'T melt the wax, ever. Soften it. If it melts and liquifies, the oils in the wax seep into the stone and repel the separating medium just like oil and water.
Make sure your separator is not expired. When it's old **** starts to get dirty.
DVA makes a silicone based separator that has no exp date; it's the best one I've ever used.
Finally, get your teeth clean. If there's no wax on them, there'll be no flashing to clean off.
 
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I think he is talking about the stone sticking to the teeth . He said it sometimes sticks to the, acrylic meaning its mostly sticking to the teeth. All the advice given is on the other side of the denture and below the teeth that is covered with stone not where the picking takes place ,except for the putty advice . He is talking about the stone sticking to teeth which is on the other side of any separator that's added . The putty is replacing the stone so that's why its coming out so clean . No monomer is passing through the putty and reaching the teeth . The only bad thing about the putty is if you pack the denture under pressure the acrylic could move or work between the putty and teeth . I've never seen a putty around the teeth that you couldn't pull the teeth right out of the putty with ease . If I do a long cure without bringing the water to a boil I have noticed the stone doesn't stick to the teeth but if I do the shorter cure and boil it for a 1/2 hour the stone really sticks to the teeth ,so something is going on during the curing boiling out stage of the processing . I have tried putting a thin layer of stone to stone separator over the teeth before the second pour in the flask but that hasn't worked . I'm going to try a wax to stone separator next but so far nothing I have found is keeping the stone from embeding into the lingual and buccal parts of the teeth where its close to the acrylic . It seems the occlusal is not effected . I hardly ever have stone embeded into that part of the teeth . I think maybe the monomer is leaching out and mixing with the stone during the boiling time during processing and cousing a chemical bond with the stone and teeth and thats why its always sticking close to the necks of the teeth . Unless you can stop the monomer from passing though the stone and into the teeth your going to have to pic it off . I'm going to try vacumn mixing die stone and painting on a thin layer around the teeth and letting that set up before I do the second pour in the flask . Maybe a harder stone that has less air holes will stop the monomer from reaching the teeth . I was also thinking that maybe a little silicone oil mixed with the stone I was going to paint around the teeth would stop the the monomer from passing through it . If the silicone putty can stop the monomer maybe the silicone oil mix will do the same thing . I think the first thing I'm going to try is a light spray of silicone spray around the teeth before the second pour and see what happens . Once I can figure out what blocks the monomer from reaching the teeth I think it will break out clean .
 
enricochienrico

enricochienrico

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I normally leave my cold, fully set stone/plaster flask (Ivobase flask) in hot water from the tap for 10 minutes, probably 50 degrees, and when I open the wax it is just soft and not melted.
Hot boiling water to fully clean and right after 2 hands of the separator.
Cleaning the back of the teeth with Q tip and monomer.
No problem at all.
 
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FASTFNGR

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I need more help! After processing there is a lot of stone stuck to the denture. It seems like I am picking it away for an hour. What am I doing wrong?

We don't have a shell blaster yet. I use Liqui-Foil tinfoil substitute to separate and I use Gibraltar Lab Stone (yellow/buff) for flasking.

It gets stuck around the teeth heavily and sometimes sticks to acrylic.

Thanks in advance.
After I boil in the microwave for 2min I remove all the teeth, paint my tinfoil substitute twice, and then put back the teeth. I pack any cure in microwave for 3 min and I am done. It comes out super clean. Make sure your tinfoil is not expired or diluted .
 
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