Shade Problems with Pressed Ingots

[labtek]

You need to equilibrate your models if scanning from a stone cast, because the periodontal ligament is not in compression.
In our experience with intraoral scanners, the ligaments are in compression when the bite is scanned leading to more accurate occlusal contacts.

I have a new pack of emax ingots shade A3. Last week I pressed two full contour units that look like A1 or even B1. Is this normal for an a3 to be this light after pressing? I did the same thing yesterday with a full contour bicuspid, same light color. When I called Ivoclar they had no ideas why. They did issue a pickup for the ingots and sent out a new pack. Has anyone experienced this before? any suggestions on technical errors that would cause this would be appreciated. thanks.

 

[labtek]

I have a new pack of emax ingots shade A3. Last week I pressed two full contour units that look like A1 or even B1. Is this normal for an a3 to be this light after pressing? I did the same thing yesterday with a full contour bicuspid, same light color. When I called Ivoclar they had no ideas why. They did issue a pickup for the ingots and sent out a new pack. Has anyone experienced this before? any suggestions on technical errors that would cause this would be appreciated. thanks.

 

[ps2thtec]

I have a new pack of emax ingots shade A3. Last week I pressed two full contour units that look like A1 or even B1. Is this normal for an a3 to be this light after pressing? I did the same thing yesterday with a full contour bicuspid, same light color. When I called Ivoclar they had no ideas why. They did issue a pickup for the ingots and sent out a new pack. Has anyone experienced this before? any suggestions on technical errors that would cause this would be appreciated. thanks.

Like magic, this this thread (and shades) changed (moved).

Anyway, what oven are you pressing in and what size ring?

 

[labtek]

Like magic, this this thread (and shades) changed (moved).

Anyway, what oven are you pressing in and what size ring?

small ring,
oven is EP500 with nitrogen tank.

 

[ps2thtec]

I had low chroma issues with an advanced fast press program that I believe are caused by overheating the pellet, burning chroma off.
Thought I heard muffles go hot before they blow. ?. .?..

 

[dmonwaxa]

labtek said: ↑

I have a new pack of emax ingots shade A3. Last week I pressed two full contour units that look like A1 or even B1. Is this normal for an a3 to be this light after pressing? I did the same thing yesterday with a full contour bicuspid, same light color. When I called Ivoclar they had no ideas why. They did issue a pickup for the ingots and sent out a new pack. Has anyone experienced this before? any suggestions on technical errors that would cause this would be appreciated. thanks.

Click to expand...

Ok, this is a longshot. Have you had this issue before, with other shades? If so it could be a vacuum issue where your press furnace is not pulling enough or none at all. Check for leaks or if the vacuum functions properly, could be unpllugged you know. Double check the parameters in the press furnace

 

[Patrick Coon]

Are you also getting a heavier than normal reaction layer? If so, this would tell me you oven is pressing hot and as ps2thtec said could be burning off the chroma. If so try calibrating before pressing again.

Also, I wouldn't expect a pressed unit to match the ingot. It will look lower in chroma due to the pressing being 1- 1.5mm thick and the ingot being 5-6mm thick. Not that I don't think that is all that's happening, but maybe contributing.

 

[Marcusthegladiator CDT]

If your oven is hot enough to burn out the metal oxides, you would have some real ugly surface textures and flash all over your pressings, they would be unusable...
I hate to ask, but are you preheating your ingots or something?
The only time I have seen this was when someone ran a press program with no plunger. So the ring never pressed. As soon as it opened, i noticed, put the plunger in and ran it again, what else could I do? So they came out Much Much Much brighter and needed to be rewaxed/pressed...

 

[Affinity]

just for kicks, press a die of a3lt and stick it in your crown, and see if it looks closer to the pellet. or use stump material. The thickness gives you chroma... if you rubber wheel a hole through emax, its almost clear at its thinnest.. Also, use your e.max shade guide in the pic and see what it looks like, its a better judge than the ingot, or the vita guide, of what a good press should look like. To me it looks light chroma wise though for an a3

 

[zero_zero]

It happened with us too..not too long ago... Had two rings to press, one HT A1 and the other HT A3... Upon divesting the A1 veneers turned out much darker and the A3 crowns were light, kinda like A1... Up until now still trying to figure out what could've gone wrong with the furnace...or burnout per se... And it's NOT a simple ingot swap.......the tech who did the pressing swears by it....so it must be somethin' else...

 

[Tooth Geek]

Funny you guys brought this up this. I too noticed the same thing this week with a tube of LT A3. I had to end up staining them significantly more than usual to achieve the correct base shade. We have two ivoclar press furnaces and they both produced hue around A1.5 out of the Lt A3 ingots. Go figure

 

[bradley ide]

No answers to why yet??!