ivocap processing

[twaite]

I see so many people here love the Ivocap but for me I'm having troubles. Why does it back flow even when every thing seems spru'd properly. Why are my models cracking even when I only press to less than 1,ooo.

I try to be so careful but still I have problems.

T

 

[droberts]

With the flask empty, hold them together and see if the white parts that your nozzle goes through are close together. If not, loosen the screws and adjust them closed. Then
flow stone into the open cracks around them to hold them. Once that is done, they should work fine. Not sure why your models would crack? How new are your flask?
I have 18 flask, some are older but not beat up and never have had a cast break. When you are investing, make sure on the second pour that the flask are
held together tightly not allowing stone to flow between them. If that is whats happening. The stone flash may be breaking of during boilout causing an open flask
situation putting all the force to the stone and not the flask once put into the compress under pressure. Do you have an area Ivoclar rep? Most of the time they
can come in and take you through the process.

 

[Flipperlady]

You have to use a tough labstone to hold up to the pressure and not crack. Try the Jesco blue diestone. The flow back could be from water level being too high or low, I can't remember which, the sprue is setting up too quickly. You can't always go by the lines, sometimes it's trial and error.

 

[droberts]

You have to use a tough labstone to hold up to the pressure and not crack. Try the Jesco blue diestone. The flow back could be from water level being too high or low, I can't remember which, the sprue is setting up too quickly. You can't always go by the lines, sometimes it's trial and error.

There is no reason to use a die stone for investing. I use Modern materials Buff stone for all denture cast and investing. There should be no pressure applied to the stone investment
with the flask halves metal to metal. The only amount of force, "pressure" that is being applied to the cast and teeth is 6 bars (90 lbs). With properly set up equipment
and the flask, there is no trial and error. This system was well design and is very consistent if used correctly.

 

[Flipperlady]

There is no reason to use a die stone for investing. I use Modern materials Buff stone for all denture cast and investing. There should be no pressure applied to the stone investment
with the flask halves metal to metal. The only amount of force, "pressure" that is being applied to the cast and teeth is 6 bars (90 lbs). With properly set up equipment
and the flask, there is no trial and error. This system was well design and is very consistent if used correctly.

Not for investing, for the model itself. The Jesco holds up well.

 

[Smilestyler]

Slightly thicker model base with a good quality stone for the model should solve the model breakage. and make sure your separator layer is thin and any model indexes are filled. I used to see hairline cracks in models a long time age too.
I have never adjusted the white insulators(thanks for that tip). I always filled that area in with stone to prevent back flow. A couple of tips that I have found to prevent back flow is to use an actual funnel when investing the first layer instead of that spacer thing that comes with it. And make sure you inject with a new clean funnel and be certain at boil out that the orifice is clear with no stone blockage.

 

[araucaria]

Slightly thicker model base with a good quality stone for the model should solve the model breakage. and make sure your separator layer is thin and any model indexes are filled. I used to see hairline cracks in models a long time age too.
I have never adjusted the white insulators(thanks for that tip). I always filled that area in with stone to prevent back flow. A couple of tips that I have found to prevent back flow is to use an actual funnel when investing the first layer instead of that spacer thing that comes with it. And make sure you inject with a new clean funnel and be certain at boil out that the orifice is clear with no stone blockage.

x2. and with the injection cylinder in place.
also ensue the nozzle doesnt move during the setting of the first stage plaster, and dont remove the nozzle & clean the stone around it - it must be a tight fit in the stone. sprue only to the tip of the nozzle too, only about 3mm across is needed.

 

[twaite]

Thank you for all the advise. I processed another case yesterday. I sprued much smaller than usual using size 8 spruing wax. I reduced the amount of pressure to 80 bar when pressing. e sure the model was down all the way. e sure the water wasn't too high. e sure the pressure wasn't too high. The case came out good but I still got back flow.
I'm thinking Dr. Roberts has the key. I need to adjust the white parts. I took pictures and will down load them later today. There seems to be space between the injection cylinder and the flask enough to allow acrylic to flow out.

 

[twaite]

 

[araucaria]

Thank you for all the advise. I processed another case yesterday. I sprued much smaller than usual using size 8 spruing wax. I reduced the amount of pressure to 80 bar when pressing. e sure the model was down all the way. e sure the water wasn't too high. e sure the pressure wasn't too high. The case came out good but I still got back flow.
I'm thinking Dr. Roberts has the key. I need to adjust the white parts. I took pictures and will down load them later today. There seems to be space between the injection cylinder and the flask enough to allow acrylic to flow out.

are you using the injection nozzles like the picture? i cant think why this problem of leakage persists like you've described. sorry if this seems stupid question.

 

[lcmlabforum]

Is your pump/air inlet gage to the pressing unit calibrated? I assume
there is a limit switch to the system somewhere . . .
LCM

 

[twaite]

Yes, that is what I'm using, for the injection nozzle. I reduced the air pressure from 100 down to 60 but it wasn't enough so I moved it back up to 80 to get the gage into the shaded area on the pressure apparatus.

 

[nvarras]

Thank you for all the advise. I processed another case yesterday. I sprued much smaller than usual using size 8 spruing wax. I reduced the amount of pressure to 80 bar when pressing. e sure the model was down all the way. e sure the water wasn't too high. e sure the pressure wasn't too high. The case came out good but I still got back flow.
I'm thinking Dr. Roberts has the key. I need to adjust the white parts.I too k pictures and will down load them later today. There seems to be space between the injection cylinder and the flask enough to allow acrylic to flow out.

This is your problem. If there is a space anywhere in the flask the acrylic will find it when it's under pressure. There shouldn't be open space between the insulating pieces and the flask.

 

[twaite]

Droberts can you take a picture of your flask and post it here. I would like to see how you flowed stone to hold up the white parts. I'm trying to do it now.

 

[droberts]

Droberts can you take a picture of your flask and post it here. I would like to see how you flowed stone to hold up the white parts. I'm trying to do it now.

Dont have any at this time. Try this... Loosen the screws, and let the white plastic insulators come together. Fill voids between the flask
and insulating parts. Once set up, tighten screws back up. If you look from the back of the flask where the injection nozzle
is inserted, you should have minimal opening of the two white insulating parts.

 

[twaite]

Dont have any at this time. Try this... Loosen the screws, and let the white plastic insulators come together. Fill voids between the flask
and insulating parts. Once set up, tighten screws back up. If you look from the back of the flask where the injection nozzle
is inserted, you should have minimal opening of the two white insulating parts.

I did this yesterday, it worked out great and it was easy to do. Thank you again.

 

[shane williams]

Thank you for all the advise. I processed another case yesterday. I sprued much smaller than usual using size 8 spruing wax. I reduced the amount of pressure to 80 bar when pressing. e sure the model was down all the way. e sure the water wasn't too high. e sure the pressure wasn't too high. The case came out good but I still got back flow.
I'm thinking Dr. Roberts has the key. I need to adjust the white parts. I took pictures and will down load them later today. There seems to be space between the injection cylinder and the flask enough to allow acrylic to flow out.

Hey don't let the professional photo and droberts handel fool ya, he ain't no dr! he works for a livin right Dan!! haha

 

[droberts]

Hey don't let the professional photo and droberts handel fool ya, he ain't no dr! he works for a livin right Dan!! haha

What do you mean "aint no dr." Havent you ever heard of "Oral Roberts". HA HA. Your right Shane, I work for a living...

 

[denturist-student]

All dental stones for models have a prescribed water powder ratio and spatulation time using a vacu-mixer.....Follow the manufacturers instructions and you should not get any fracturing. The one case I had that developed a palatal fracture was a void under the model which was thin anyway. Turned out it was fixable and the patient walked away with relined dentures. Suction was good even though the palat had cracked in the centre and caved in a bit. Oh well I should have taken a picture for the palm face case.....If we don't follow the manufacturers instructions for mixing stone and acrylic we will run into potentially disasterous consequences....I have used whipmix stones without problems with the one exception when I was in a hurry and the cast caved in in the palate....Oh well....Another one for the books.