White dots

[RCKSTR]

Have any of you experienced white dots on your crowns post sintering?

Only occurs on occlusal surface.

It happens in 2 ovens, eliminating oven contamination.

It happens on both dipped crows and crowns milled from pre shaded discs, so its not the shade fluids.

Considering the beads, but we've replaced the beads and had the same results.

They are perfectly round dots and not constant with skin oil contamination.

Could high temp be affecting them?

Ignore the dark color, we marked it with a black X on the inside.

 

[2thm8kr]

Now the boys all thought that I'd lost my sense
Those telephone poles were like a picket fence
They said "Slow down, I see spots!"
The lines on the road just looked like dots

 

[CatamountRob]

Now the boys all thought that I'd lost my sense
Those telephone poles were like a picket fence
They said "Slow down, I see spots!"
The lines on the road just looked like dots

Took a corner; sideswiped a truck,
Crossed my fingers just for luck.
My fenders was clickin' the guardrail posts.
The guy beside me was white as a ghost.

 

[RCKSTR]

My old lady and the girl next door when floating down the river on the **** house door.

God made satan and satan made sin, so god made a hole and put satan in.

 

[rkm rdt]

Smoke was comin' from outta the back,
when started t' gain on that Cacillac.
Knew I could catch him, I thought I could pass,
don'tcha know by then we'd be low on gas.

 

[RCKSTR]

Not sure how Hot Rod Lincoln applies but I like it

 

[2thm8kr]

And then there's Grandma,
Swingin' on the outhouse door,
Without her nightie,
And Grandpa yellin', "More, More, More!!!"

 

[2thm8kr]

Not sure how Hot Rod Lincoln applies but I like it

The lines on the road just looked like dots

 

[CatamountRob]

We had flames comin' from out of the side.
Feel the tension. Man! What a ride!
I said, "Look out, boys, I've got a license to fly!"
And that Caddy pulled over and let us by

 

[sirmorty]

I wish I could help, but maybe it's just a bad batch of Zirconia. Are they from the same puck?

 

[Glenn Kennedy]

 

[RCKSTR]

Its from all brands, not just one ZR

 

[zero_zero]

 

[keroassidy]

Im very intrigued by those spots. I wish someone that has seen or heard of could help. Im new to milling and sintering and havent seen that but would like to know as to not repeat those results. Hope you get a serious reply

 

[grantoz]

its from your beads or the base that you sit the crowns on, time to change them which ever you have.i sometimes wet and dry my alumina base clean if i dont want to pay for a new one.as they say in my part of the world im a tight arse or as the Chinese say an iron chicken you cant even get a feather out of one of those bastards.

 

[Toothman19]

or when you're dipping the crowns the color isn't penetrating all the way through cause the crown is sitting on those spots

 

[GoldRunner]

We saw this when the elements of our furnace started to go bad. At first I thought it was free silica that was sluffed from the elements and was on the surface of the tray. When it went through the next heating cycle the silica was wicked into the zirconia where it touched the tray. Only on the cusp tips. Both of your furnaces could be contaminated. It can happen very easily, especially if you dry with a lamp.

Because you do dip, make sure that they are very dry from a toaster oven or else the residual solvent will contaminate both your furnaces and elements. If that is the case both non dipped and dipped crowns will get the white spots. Just as you described.

We had some luck with firing chunks of zirconia at higher temp to "clean the furnace" and condition the elements, but eventually the solution was to replace all the elements. If your elements are not nice and clean, depending upon the type, they will look blotchy or overly glazed.

 

[CoolHandLuke]

this is probably where the unit was in contact with the bead tray. don't let it touch the tray. its a giant heat sink.