Willi Geller shades problem...

[howitsmade]

Hey there my friends and guru's. I'm reading this forum for a long time, but this is my first post here.
After 7 years working in lab focusd on ceramic restorations I decided to start my own lab, also focused on porcelain. I have decided to make this journey with Creation CC and ZI. But i have found big difficulties with correct build up and shades. I have read all manuals at the internet, have seen every video (which is cool),have read all threads on this forum, but I still have problems. I need to know base, mains rules. I know that Creation=be creative, but like I just said, I need to know how to build up a standard A2 (example) crown using 2-4 powders. To be honest I don't like dentine/enamel crown, I think it has absolutely no life (unlike ceramco3),but its only my opinion.
Clear, under enamel or on enamel? HT's powders over whole crown on dentin or only on margin area? Dentin A2+Si04 (1:1)=more translucent A2 dentin?
I will be very glad if someone would help me, and start this discussion.

 

[2thm8kr]

What do you not like about your results?
Creation ceramics are chroma rich, that is why you have so
many translucent materials.
Try a transition powder. Mix a blend of 20% of your most translucent enamel with 80% dentin in the shade you are building. Put a thin layer down before your enamels and see if that adds a little vitality.

 

[user name]

As with any ceramic thats new to you, fire some small chuncks and keep them handy so you know what each actually looks like...but fire them at th proper temp. Nothing will leave your glass more dead and lifeless or with chroma and value out of whack than firing at the wrong temp.

Small amount of CLEAR porcelain setting on a piece of platinum foil on either a firing peg or equivalent height pillow tray stack. Fire samples at different temps until you actually hit clear. Not frosty, not cloudy. 5 degrees will change everything when youre close. Thats the magic temp for your set up. No need to step down temps for multiple firings. Get it right without a substantial hold. Subsequent layers will fire at the same (correct) temp without distorting your underlying mass (of which there shouldnt be much...because you designed your frameworks properly).

2thm8kr is correct, that Creation is chroma rich. Design your build just like a real tooth...cover the entire thing with enamel, not like some old skool ceramco deal with enamel just at the incisal 1/3.

 

[mcfly]

Creation is a lovely porcelain but as User name mentioned you need to test the porcelain ,eventually you will become a master with it.When crown is too low in chroma you can add HT porcelain and SI porcelain to increase the chroma but this is all with trail and error.
Make a couple metal copings and play around and see if you can re create natural teeth ,practice is the name of the game and i am still learning and i use the porcelain all the time .Good luck and post results ,im sure i will learn from you too.

 

[howitsmade]

I have Zubler Vario 200 (new one),so the temperatures are ideal.
I have made couple of crown (molar and premolar) and 3 unit bridge to show it to the doc's. As a technician I see a imperfections (my boss also have seen it). Doc's said "very nice work" (one doc said molar made by dentin/enamel is prettier, other said made by OD32/DA2/S58/HT52/SI02/CL0 is prettier),and I'm still uncertain about my works. I have a problem with cutoff the enamel. I see the line between dentin and enamel. I've read that Creation need a bigger cut back, but if I put to much enamel crown looks to gray (Creation doesn't forgive it).
mc fly please tell me what powders do You use on the first bake (A3 shade)?
thanks guys for a response

 

[howitsmade]

I have a question... Is it true that for shades from C1 to D4 we should use OD44 (I've read this in manual)? It is kind of brown powder. So ma second question is where I should put that OD44 on crown C1 and where for C4? I know that Creation dentine's are quite opaque so we don't need to use ODA1, ODA2 etc... It's strange that we use the same dark OD44 for very bright colors and for dark ones. Can anyone explain me this?
And the other thing: Does anybody use shoulder powders? Is it necessary to have every SP opaque and SP translucent? Or maybe couple of them will cover every the most common shades?

 

[user name]

Slow down...Just because you have a new oven with preset temps doesnt mean thats the temp you should be firing at. You still need to dial everything in with clear porcelain. You sound very new to this, so do your self a favor and step away from the Creation. Get a starter set of InLine. You can do basic builds with decent results using InLine One. If you are able to control your builds and get the boss' approval on contours and anatomy, then start using dentin/enamel. When you see the short comings, find the powder to cure the issue and on to the next step. Im just getting the feeling youre diving in without really knowing whats going on. Start with your oven.

 

[howitsmade]

No, no, no... What was I saying was that I'm pretty sure that oven's temp are good... But I will check it using clear very soon to be 100% sure.
My questions about Creation were due to the fact that Ceramco3 (which I was using for couple of years) is very different. I know this was "he knows nothing" kind of questions.
Definitely I will fire some chunks and will glue it on the top of the jar, I had to do this 2 months ago.

 

[desertfox384]

What is the thickness of the porcelain on an average case for you? Too thick/thin will of course mess with the shade.
What is your layering technique? You are seeing a gray line on the incisal 1/3 because you are lacking a transition powder.. Try a thin layer of C1 opacious dentine on the transition area, then layer your dentine and enamlels over that, it will help the incisal from graying.
Check your thicknesses as you build, I need 6-7 tenths of dentines before layering any enamels or effect powders.

I would suggest Gerald Ubassy's book shape and color - This book will teach you how to layer properly.
http://www.amazon.com/Shape-Color-Successful-Ceramic-Restorations/dp/0867152079

 

[cdtwade]

OMG somebody is talking out layering porcelain??

 

[howitsmade]

So I've made clear's chunks. First at 920*C, second at 930*C. But I don't see any difference. Maybe I'm blind, I dont know. I've mada a photo, but it's poor quality, I don't know if you will see anything. It doesn't look like glass, rather like frosty window. Tickness of those chunks is about 0,7mm.

Link: http://www.fotosik.pl/pokaz_obrazek/acf300c671296c9c.html

 

[user name]

So I've made clear's chunks. First at 920*C, second at 930*C. But I don't see any difference. Maybe I'm blind, I dont know. I've mada a photo, but it's poor quality, I don't know if you will see anything. It doesn't look like glass, rather like frosty window. Tickness of those chunks is about 0,7mm.

Link: http://www.fotosik.pl/pokaz_obrazek/acf300c671296c9c.html

Keep doing it; youre on the right track. Try one at 910, one at 940. When youre able to see the difference, youll be getting close to finding the answer. Ive seen 'factory temps' from the porcelain mfrg off by as much as 50 degrees. Its a process, but worth it. When your glass isnt fired to proper temp, opacity, chroma, value...everything will be off.

 

[howitsmade]

To be sure, fired Clear should be like window glass? Almost 100% transition?

 

[user name]

Not all brands will get crystal clear. The goal is to find the sweet spot though, where its best. As I recall from using creation though...it was one of the more clear. Surface can hide alot, so if youre not laying it on platinum foil you might need to do a quick surface and polish to eliminate some surface haze. The pics you posted are definitely not clear. You should be using water for your test medium.

We had a lengthy thread on this some time back. Ill find it for you.

 

[user name]

Here you go...
http://dentallabnetwork.com/forums/...idnt-achieved-the-clear-look.9467/#post-55038

As Al pointed out...vacuum can be an issue as well.

 

[howitsmade]

ok, thanks Im not sure if my CL0 is absolutely clear. In Creation's color chart is shown that window, HT51 are more translucent (I don't have both). So how can I set correct temp without having real clear powder?

 

[user name]

Look closely...very close. Fire multiple tabs at different temps. You want to go from a grainy surface to more glassy, with out loosing detail on the edges.

 

[desertfox384]

User, how clear did inline come out for you and at what thickness?

 

[user name]

I dont have pics, but it wasnt bad. Not 'clear' though. I make my tabs thicker at one end; about a millimeter and they feather out to very thin. After I get what I think is my good temp, then Ill stick that tab in some peg paste leaning at an angle and fire it again to verify that it doesnt slump.

 

[howitsmade]

Ok, so I have made 6 clears samples. Each at different temperature.

As you can see non of this samples is as clear as my glass dog
The first one was fired at 900*C, second at 920*C, third - 940*C, fourth - 960*C, fifth - 980*C, sixth - 1000*C (I know it's way too much but I wanna try what will happen).
The last one (1000*C) is transparent but it has rounded edges. Fifth in my opinion is prettier than the last on (even more transparent and more sharp edges). The fourth one is much less transparent but it has sharp edges like it should have (in my opinion). The third and second (second was fired at temperatures that is in my manual) are much less transparent (it doesn't look like clear at all),but they have sharp edges. The first one is smoky, cloudy etc, but it was just an experiment.
Every bake was made at the same temperature increase (55*C/min) and holding time (1min).
Can you guys tell me what next? For me fifth chunks looks the best but I'm afraid about such a high final temp. (it's 60 degrees higher than original temp).