Intraoral scanner crown margins

[Car 54]

What about phantom margin syndrome? Or Schrodinger's margin? If you never feel the margin with the explorer, is it open, closed, or both at the same time? Does measuring it change the outcome?

That's to deep for me, Obi Wan



Or, how about this one I've posted before

 

[Car 54]

120 or more is for Drs that mill their own crowns.

That number may be true in this regard, wasn't the gap on the original chairside Cerec was about 100 micron, so maybe the ADA came up with that number to clear, give them a clean conscience for the Dr's using that system? Or, has that number been out there for awhile?

 

[Pronto]

Wouldn't doubt it. Got to pay for that lease you know.

 

[TheLabGuy]

That number may be true in this regard, wasn't the gap on the original chairside Cerec was about 100 micron, so maybe the ADA came up with that number to clear, give them a clean conscience for the Dr's using that system?

120 microns is huge...an average dental explorer is only 80 microns. My Docs would line me up to be a recipient of a firing squad if I sent them a crown with those parameters.

 

[Car 54]

80 micron, thanks for the more up to date number.

 

[rkm rdt]

120 is huge enough to drive a truck through...honk honk.

 

[bigj1972]

I always thought the maximum was 100. Or at least that was the excuse for 3D printing models for faster production.

 

[rkm rdt]

I always thought the maximum was 100. Or at least that was the excuse for 3D printing models for faster production.

I just preordered the Herpes Simplex model https://www.renfert.com/usa-en/PM/Products/Equipment/3D-filament-printing/SIMPLEX
I believe it's 50 micron and no post processing.

 

[bigj1972]

I just preordered the Herpes Simplex model https://www.renfert.com/usa-en/PM/Products/Equipment/3D-filament-printing/SIMPLEX
I believe it's 50 micron and no post processing.

 

[bigj1972]

View attachment 40489

≥50 μm
And with a .04 nozzle, it'll be more like 200 microns

 

[rkm rdt]

 

[bigj1972]

 

[rkm rdt]

 

[bigj1972]

 

[Jack_the_dentureman]

it's about the end result, in the mouth. not how we will do on the model.

it's not about the scanner or milling itself

a curiosity in the research I read, the crown before cementing has a margin gap 39 μm and after cementing 59 such a trick with cement.

 

[sirmorty]

Any advice for the margins?
Some of it is visible but then it just fades away.

 

[rkm rdt]

Any advice for the margins?
Some of it is visible but then it just fades away.
View attachment 40683 View attachment 40684 View attachment 40685 View attachment 40686

Probably should have removed the cord on that one.

 

[LarryRDC]

Here , I marked this one for you..

 

[HonestAbe]

Took a stab at it, just make the margins thicker like this, easy.

 

[Smilemaker1234]

Scanning is all about isolation and retraction. If you can see the margin and the margin is the issue here, take two seconds and mark it. Makes no sense to me why Docs don't, you literally just prepped it. However, if they are printing and making a restoration from that printed die/model, that's a big no-no. Always make your restorations from the scan data.

I agree . Printed models are not as accurate. Always make restorations from scan data.