Mispress on Emax

[labwoman]

My friend bought a Whip Mix propress 200. I went to her lab and I showed her the steps for making an emax crown. It was an inlay and was perfect. A couple of days ago she called me very upset, she had pressed 3 different crown with the below results. I can't go and help her since I live in Arizona and she in Massachusetts. I asked her the procedure. She burns out the ring at 1600 for 45 minutes, quickly puts in the ingot and plunger she said it takes her about 10 seconds, and the oven is very close the the burnout. I think even though the pressing oven says 925C, I believe the oven is wrong and it is not hot enought. After looking at the pictures please comment thanks.
I hope this works. I have attached

 

[sixonice]

these are defintely "cold" pressings. her spruing looks nice, this is a temperature issue. i would recommend that she raise the high temp to 935 Celcius. make sure she adjusts her vacuum release/stop to 1 degree below the new high temp (which would be 734 C). the other parameter she can look at is the pressing time. 9 minutes seems to work well. i would make the adjustment first on the high temp and see the results before she adjusts the pressing time. double check with her and reinforce that the total height of the waxed restoration and the sprue should not exceed 16 mm. from your pictures it looks like she angled the units nicely in the ring also.

 

[Mike2]

Not to disagree with Six, but I have also seen these result from thin areas in the wax-up. If an area is too thin the material cannot flow through.@cents

 

[user name]

Shes gotta change the angle shes sprued them. As the gooey material is pressing in the sprue and entering the pattern, shes making it change directions and head back towards the middle of the ring. Like Six said, a little more heat will fix it, but try to keep the material flowing towards the side and end of the ring...not changing directions.

Changing the angle of the photo would show it better.

 

[desertfox384]

Looks like the angle could be improved a little..but like they said above that isnt the problem...looks too cold. My propress has done the same a few times.. up the temp (ivoclars ep ovens fire hot) i think im 25 degrees c above ivoclars recommended temps.. she can call ivoclar with the issue but im willing to bet they tell her the same thing.

 

[charles007]

Only have a minute....your sprues look very long .....and centered in the middle of the ring.....Tell her to get a manual///
Temps and such... have no clue

 

[ps2thtec]

Is she using the 100gm, or 200gm ring. If 100gm than looks like a violation of the 10mm
rule. I went through this in the beginning. Keep wax paterns 10mm from the ring wall. Hard to do in 100gm. Have to position over plunger. More than two units, use 200gm.
I use old Optimal Autopress oven using Ivo's temps & H2-5min for 100gm, 7:30 for 200gm. And keep sprues to 3mm length!

 

[paulg100]

Mike2: not so sure about the wax thickness being an issue, i pressed 6 veneers a while back as a test case at 0.09mm thick and they pressed perfectly.

I think if the rest of the settings are dialed in properly then there is hardly any limit to the thickness you can press at!

The biggest challenge is keeping the wax up in one piece at those thickness's.

And as for sprue angle, im pressing implant copings at 90 degrees now regularly to stop investment break off in the coping, with consistent results. Again i think this is less critical than some of the other parameters.

 

[grili]

Help
What diameter sprue dou you prefer to press e.max ?

 

[Brett Hansen CDT]

8 gauge. i usually keep it around 3-5mm long. I also make sure that the length of the sprue and the crown does not exceed 15mm.

 

[AL1]

I have a friend here in Seattle, that uses a whip mix a pro press and he was getting miss presses. He was told that the thermo-couple might be contaminated and stopping the computer from reading the muffle heat. He was told to purge the oven, which he did, and doesn't seem to have problems any more.

 

[Eficko]

I had pressing short problems like this on a few crowns before Christmas. For me it was the pressure. One of the hose's had a tiny hole it that was letting air out and the pressure wasn't high enough

 

[hickory94]

My friend bought a Whip Mix propress 200. I went to her lab and I showed her the steps for making an emax crown. It was an inlay and was perfect. A couple of days ago she called me very upset, she had pressed 3 different crown with the below results. I can't go and help her since I live in Arizona and she in Massachusetts. I asked her the procedure. She burns out the ring at 1600 for 45 minutes, quickly puts in the ingot and plunger she said it takes her about 10 seconds, and the oven is very close the the burnout. I think even though the pressing oven says 925C, I believe the oven is wrong and it is not hot enought. After looking at the pictures please comment thanks.
I hope this works. I have attached
View attachment 1252

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View attachment 1254

I would extend your H2 time by say 5 min.

 

[Bedrock]

I was having trouble also and used some of the info on here, very helpfull, thanks.