Mpa Of PFM

[sampson]

Zirconia = 1000 mpa
Ld emax = 400 mpa
Can some one please remind me of
the average Mpa for porcelain fused to non Precious Metal.
thanks

 

[Al.]

Zirconia = 1000 mpa
Ld emax = 400 mpa
Can some one please remind me of
the average Mpa for porcelain fused to non Precious Metal.
thanks

Most layering porc is less than 100. Between 80 and 110.

That includes the porc you layer over zir, emax, and pfm frames.

Press to metal is around 130 mpa.

When you tell your Drs zir is 1000 mpa remember that is the frame only, the weak link is the layering material and the questionable bond.

Thats why emax is so hot, at least for now, because it's being pressed or milled full contour in the posterior, removing that weak link.

 

[sampson]

thanks Al
- thats kinda what i thought
- the layer of porcelain can still debond and leave the super strong zirconia frame exposed.
-did you mean that the LD emax posteriors can be made without a layer of colored porcelain over the core material
- is this regarded as a monolithic unit?
-and if so ,how do the aesthetics compare between monolithic and layered posterior crowns
- how does this monolithic crown (emax core material only) compare -strength and color wise to Cerec inoffice milled crowns
thank you for your time
Karl

 

[Al.]

Yes that is what monolithic means. It is one solid peice.

Its also called press and stain. Treated like a full gold crown but instead of polishing you stain and glaze. Same with bicuspids exept you layer the facial only for max strength.

Ive got tons of pics probably a couple hundred of my production press and stain posterior emax crowns.
Ill post some and you can judge the esthetics your self.

Most cerec I see none in office look like crap.
Ive seen plenty pics posted of crowns I couldnt sell and the Drs are proud as pea****s of it.
Drs compromise esthetics in the posterior to save time, to get the patient out as quick as they can. They have them wait in the reception room so every crown is a rush and most Drs are not very good lab techs.

 

[Al.]

Travis, the site thought I posted a dirty word.
Pea**** is the bird.

Thats funny.

 

[Travis]

I laugh when I think what goes there.


peasoup

 

[labdude]

Actually...peapenis

 

[Travis]

I have never heard of the pea word.

Thats 5 letters, there arent that many four letter dirty words.

What is going on with you signature.

I didnt think anyone would figure out they had alot of space in the sigs for pics.

 

[labdude]

Horsie pic. I like horsies.
Linda doesn't care for this one for some reason.
Something different.

 

[Al.]

Karl,These are all press and stain emax. I used LT.
LT can be opaque in some shades but HT can be to grey, I here they are coming out with a MT or Medium Trans ingot soon.

You will get much nicer results if you layer with incisal but that will compromise strength for posteriors.

 

[clearH2O]

Hi AL, you make press eMax look too easy. I think I am OK for waxing and die prep as for PFM or full crown, but still unsure with eMax LT especially at the margin. Would you please advise me your technique ( if you have pictures) on waxing and polishing LT, HT around the margin?
Thanks
ClearH2O

 

[Al.]

Hi Thuy,

I wax the margins exact, I dont overwax them then go back and thin them out, except where they feather edge. I wax those areas a bit thicker.

I find they usually press nicely to 10X magnification, but there are areas sometimes that may be open from the devesting process or they just press that way.
I add these spots with low fusing porc during or after the glaze bake.
They have a sholder porc that I think is a bit higher fusing that would probably work nice for this but I never have tried any of there shoulder powders.

I go over my margins with a bush silent stone. It is a very smooth stone and does not chip the porc and I can smooth the porc and make it flush with the die.

I get better margins with emax than with cast pfms and as good as gold crowns except I dont have to polish so no chance of over polishing like you do sometimes with fgc's. And if I do or chip a spot I add on with low fusing.

The Drs tell me they cant feel the margins with explorers and I have a couple of Drs that used microscopes on their patients and they have told me the margins are better than pfms.

Just dont get glaze on the inside of the crowns just like on pfms. If you do with pfms you sandblast but you cant do that with all ceramic you have to grind it off with a highspeed.

 

[clearH2O]

Thanks for your quick response. Al, you are a generous man.
clearH2O

 

[Al.]

Your welcome, mabey you will remember me when I am an old man and hire me to dust off your equipment.

 

[labdude]

I didn't read that...nope I didn't see it....push back from the keyboard....it will pass...let it pass...it will pass....

AL'S GONNA DUST OFF H2Os EQUIPMENT!!!!
:whoo::rofl:2:bounce::laugh:2

Sorry Thuy, that was to good to pass up.

 

[sampson]

thanks for the info Al

 

[Al.]

I didn't read that...nope I didn't see it....push back from the keyboard....it will pass...let it pass...it will pass....

AL'S GONNA DUST OFF H2Os EQUIPMENT!!!!
:whoo::rofl:2:bounce::laugh:2

Sorry Thuy, that was to good to pass up.

Dude, you have obviously never met Clear Water.

 

[Al.]

Horsie pic. I like horsies.
Linda doesn't care for this one for some reason.
Something different.

Here you go Dude, mabey she will like this pic better. Mabey bring back fond memories of you before Viagra.

 

[wwcanoer]

Al,

Do you use the preformed wax occlusal/forms on your posteriors? Or just a very gifted waxer..........

Thanks,

Carol

 

[Al.]

Al,

Do you use the preformed wax occlusal/forms on your posteriors? Or just a very gifted waxer..........

Thanks,

Carol

Hi Carol, No Im no super waxer I use the occlusal forms.

I will say though I am a much better waxer now than I was 4 yrs ago.

I used to suck at gold crowns but since the increased demand for emax I have gotten ALOT more experence waxing full contour crowns.
( Is suck a bad word now?)

I probably could hand wax occlusals like the molds now, but It would probably take me way over an hour.

Next week I have 22 copings to wax for pfm, but I have 37 emax to wax, and 1 FGC. So since I dont have a machine to spit out wax ups, I have to wax from start to sprue, at least 4 full contours per hour that will have me done with all the emax in just over 9 hours.
Realisticly I wont get them done that fast. I will have to add 4 or 5 hours because of potty, coffee breaks, stretching breaks and a nagging wife that wants me to pick up after myself.