Pressables and Zirconia

[cheadlemick]

Hi everybody, I'm doing a lecture on materials,specifically E-Max and zirconia! Does anybody out there have any info,knowledge,or experience of Dicor,Cerestore or Hi-Ceram? I'm looking at the development of the modern materials from materials such as these. Also can anybody let me know why Empress 2 was such a disaster?
By the way i'm a Dental Tech so have a good amount of knowledge of the modern stuff so im looking for something out of the ordinary! Just snippets will do! Many thanks in advance

Mick

p.s I will
be giving full acknowledgement to any body who contributes!

 

[Mark Jackson]

Hi everybody, I'm doing a lecture on materials,specifically E-Max and zirconia! Does anybody out there have any info,knowledge,or experience of Dicor,Cerestore or Hi-Ceram?

I had all those systems.

 

[cheadlemick]

I had all those systems.

What would you say were the main problems Mark? And if i was cheeky enough to ask for some details would that be ok?

 

[user name]

Dicor...It was expensive to get into, only one material supplier and the cost of glass shot up. Not terribly strong. No way to controll opacity. I prefered to do all ceramic anteriors with refractory and Optec. Once Finesse came along with both press and powders, thats where I went.

e.max changed everything.

 

[cheadlemick]

Dicor...It was expensive to get into, only one material supplier and the cost of glass shot up. Not terribly strong. No way to controll opacity. I prefered to do all ceramic anteriors with refractory and Optec. Once Finesse came along with both press and powders, thats where I went.

e.max changed everything.

excellent stuff im trying to build a timeline of the development of all ceramic crowns from the PJC PT foil Dicor and Cerestore and HiCeram to the present day!

 

[BobCDT]

Empress 2 was actually lithium desilicate or todays e.max first generation. Initially it was too opaque to be a monolithic material. So, Ivoclar developed a layering system to put on Empress 2 frameworks. To make a long short, The TCE didn't match and there were thousands of units delaminating in the mouth. In addition I think there were problems with the reaction layer not being fully removed. This also contributed to the delaminating of the layering material.
Bob

 

[BobCDT]

Produced a lot of Dicor. It looks great when matching shade D2. Only one color material. At the time cement technology was nothing like today. If i recall correctly we didnt etch the restorations, nor were they bonded. As a result, like all of the all ceramic predecessors it failed more than an acceptable amount. not sure what the flexure strength was. Probably under 150MPa.
From a manufacturing perspective, there where also problems. The glass was not that dissimilar from pressed ceramics. But, Dicor was cast using centrifugal force. The casting temp was extrimely narrow and casting was unpredictable. For the time the system and materials were expensive and Dentsply was of little help with technical
Support. Corning, partnered with Dentsply and also offered no real support.
I think my age is starting to show.
Bob

 

[BobCDT]

Time table:
Alluminious jacket crown introduced in the late 70s or early 80s by Vita. Platinum foil matrix. Layered high strength core and porcelain application. Great esthetic results.
Dicor mid 80s
Cerestore late 80s (never made one)
Empress early90s
These are approximate intro time frames.
Bob

 

[user name]

You forgot to give some credit...Dicor was a Coors-Corning idea. Id bet, looking back, the ingots were almost a pyrex glass. I believe another problem with the empress 2 was soft tissues showing a little reaction, so the prep guides were changed saying that margins should be .5mm above the gums. For the ultimate in esthetics, it had to be Finesse. Pressable ingots galore and beautiful porcelain.

 

[user name]

What was that aluminous core stuff...Willglass? Willceram?

 

[CatamountRob]

What about Inceram? We did them, but I can't remember what it was.

 

[BobCDT]

Never did Inceram. Strong core. Too many failures.
I think Dicor was developed by a lab tech in Boston and later sold to Dentsply and Corning.
The alumina core jacket crown was an alumina (high strenght) build up on platinum foil matrix. High temp firing cycle. Then, conventional porcelain build up, stain and glaze. This was a Vita product and was really great looking.
B

 

[EJADA]

Empress 2 was actually lithium desilicate or todays e.max first generation. Initially it was too opaque to be a monolithic material. So, Ivoclar developed a layering system to put on Empress 2 frameworks. To make a long short, The TCE didn't match and there were thousands of units delaminating in the mouth. In addition I think there were problems with the reaction layer not being fully removed. This also contributed to the delaminating of the layering material.
Bob

Let us not forget about Eris. (empress 2 repackaged with the CTE issue fixed) I made hundreds of successful Eris most of which are still in use. I was a great product that got the Empress 2 bad wrap. Then of course the original Empress beautiful just to weak.

 

[BobCDT]

Let us not forget about Eris. (empress 2 repackaged with the CTE issue fixed) I made hundreds of successful Eris most of which are still in use. I was a great product that got the Empress 2 bad wrap. Then of course the original Empress beautiful just to weak.

Hi,
I agree, Eris was a great product.
Bob