Printed model accuracy. What to expect?

[Marcusthegladiator CDT]

So we have had the Edin260VS and a Trios for a while now.

I just want to point out a few issues in hopes someone here has a solution.
But keep in mind I don't expect printed models to replicate what a fantastic impression and stone cast can replicate. And this is only discussing a fully digital workflow from a Trios scan.

1. We were hoping that if we had the contacts perfect on the printed cast, it would be perfect in the mouth.
No, not at all. If we build perfect contacts on the printed casts, they are very open in the mouth.
So we leave them tight. But not a little tight. VERY tight. This is a problem.

For now we are just adjusting our contacts to .01 and trusting this is optimal. And then adjusting the
printed casts to fit.

2. When building monolithic crowns we set our occ distance between .2 and .3 and this has been
acceptable. But when layering porcelain over a zirconia frame, the occ on the printed articulated casts
hasn't been the most accurate.

3. The MED6XX material printed on the 260vs is very soft and leaves crowns bouncing. It also abrades
easily. It seems that no matter how clean we blast or scrape them. There is always more film to be
scrapped off. The abrasion and malleability of the material leaves a lot to be desired.

We are almost strictly keeping the fully digital workflow to single unit cases. But would like to dial it in to broaden that spectrum.

Still, we have been happy with this system considering.

But, what can be done to resolve the printed cast issues?

Thanks.

 

[CoolHandLuke]

if you find out let me know.

recently a new client trying us out for the first time complained that our models from the eden didnt match the models coming out of argen, so i did a scan.

our models and their models had a 19um discrepancy (discounting errors in the scan) on both contacts.

this is within the 30um XY tolerance.

can that be improved upon? no. could it be worse? yes.
is it just as possible to have a crown that is 20um too big on both sides? absorutery.

is it worth pissing and moaning?

nah bro.

 

[rkm rdt]

I send my prints to Argen and have had perfect results.My pfz contacts and occlusion are fine . I'm not sure what printer they use .

Their model material can abrade as well and so the dies can get wobbly in the model after repeated use.I changed to a solid model with a separate die to overcome this and it works better.

You could try leaving your contacts in zirconia when cutting back.

Do you use the 3 post articulation ?

 

[JohnWilson]

We are just getting into this market, I have probably 100 sets of models/singles and small bridges done now and I have been ridiculously impressed with how accurate the models are to our milled restorations. We use Argen as well

I received a very nice call from a newer client that seated his first half a dozen Trios crowns yesterday. He was in awe how perfect the margins/contacts/occ was. He said out of 6 he had one minor adjustment on a lateral excursion.

I was plenty happy to hear this as the workflow is so damn fast and efficient.

 

[JohnWilson]

I send my prints to Argen and have had perfect results.My pfz contacts and occlusion are fine . I'm not sure what printer they use .

Their model material can abrade as well and so the dies can get wobbly in the model after repeated use.I changed to a solid model with a separate die to overcome this and it works better.

You could try leaving your contacts in zirconia when cutting back.

Do you use the 3 post articulation ?

When I eliminated the gluing by starting to use the small 3shape articulators I felt it was a real improvement. One less variable. I found us adjusting occlusion when we glued way more.

I did a few with the posts and while it absolutely helped I just like the convenience of the the precise little clacker articulator

 

[rkm rdt]

When I eliminated the gluing by starting to use the small 3shape articulators I felt it was a real improvement. One less variable. I found us adjusting occlusion when we glued way more.

I did a few with the posts and while it absolutely helped I just like the convenience of the the precise little clacker articulator

It's a pricey articulator but it works well. Be careful with the springs that can bend if you rotate the bases. I had to do surgery which wasn't fun.

 

[Marcusthegladiator CDT]

When I eliminated the gluing by starting to use the small 3shape articulators I felt it was a real improvement. One less variable. I found us adjusting occlusion when we glued way more.

I did a few with the posts and while it absolutely helped I just like the convenience of the the precise little clacker articulator

I ordered 3 3shape articulators from Core3D. At first they were great. But then an assistant across the hall threw two of them away. WTF!
She knew it was ok to toss the 3d models when they were done. But who would think that pretty little CNC machined piece of heavy metal would go in the trash? Idiots. So we had one left, and at $150.00 I didn't want to order more. We still have it. But don't us it.
The models interface fit the 3shape articulator so incredibly tightly. I have to break the capillaries in my fingers to rock them off. Then I watched another idiot take a full size hammer to the articulator to remove the printed casts. As he was denting up the pretty little CNC machined 3 shape articulator. I wanted to scream, "WHAT THE HELL ARE YOU THINKING YOU STUPID BASTARD!." But instead I asked him to please not beat the pretty little $150.00 CNC machined articulator with a hammer.
I was thinking about adjusting the dimensions of the printed casts by 1,2,3% to see if I can dial them in.
I will see how it goes and let you guys know.

 

[JohnWilson]

There are many base styles/ dimensions for the 3shape articulator, make sure you use 2.3 .40 the connection interface is 40 microns undersized and you can (more) easily remove them.

Throwing them out is just idiotic have no clue how even the most idiotic person would consider that correct.

 

[kev]

Hey guys how much are the models from Argen? Are the models with removable dies just ask accurate as the solid ones?


Sent from my iPhone using Tapatalk

 

[rkm rdt]

The price of the Argen models are exactly what we should be charging for our models.

 

[Car 54]

---------
--------- I have to break the capillaries in my fingers to rock them off. Then I watched another idiot take a full size hammer to the articulator to remove the printed casts. As he was denting up the pretty little CNC machined 3 shape articulator. I wanted to scream, "WHAT THE HELL ARE YOU THINKING YOU STUPID BASTARD!." But instead I asked him to please not beat the pretty little $150.00 CNC machined articulator with a hammer.
I was thinking about adjusting the dimensions of the printed casts by 1,2,3% to see if I can dial them in.
I will see how it goes and let you guys know.

Tactfully done, Marcus. It's the other skill as a employer or supervisor that sometimes can be taken for granted, that employees etc. may not understand that side of our holding back and diplomatically getting a point across.

 

[KentPWalton]

I ordered 3 3shape articulators from Core3D. At first they were great. But then an assistant across the hall threw two of them away. WTF!
She knew it was ok to toss the 3d models when they were done. But who would think that pretty little CNC machined piece of heavy metal would go in the trash? Idiots. So we had one left, and at $150.00 I didn't want to order more. We still have it. But don't us it.
The models interface fit the 3shape articulator so incredibly tightly. I have to break the capillaries in my fingers to rock them off. Then I watched another idiot take a full size hammer to the articulator to remove the printed casts. As he was denting up the pretty little CNC machined 3 shape articulator. I wanted to scream, "WHAT THE HELL ARE YOU THINKING YOU STUPID BASTARD!." But instead I asked him to please not beat the pretty little $150.00 CNC machined articulator with a hammer.
I was thinking about adjusting the dimensions of the printed casts by 1,2,3% to see if I can dial them in.
I will see how it goes and let you guys know.

You SHOULD yell at them! Makes you feel better and it get's through the thick skull!

(Sarcasm)

 

[PearlZ]

no what you should do is QA their case with a hammer.

"oh this is zirconia? better perform a hammer test" *smash* *smash* the look of horror on their face is your cue to say something about not using a hammer on the articulator like a knuckle-dragging neanderthal.

 

[CAD-CAM Jedi]

3. The MED6XX material printed on the 260vs is very soft and leaves crowns bouncing. It also abrades
easily. It seems that no matter how clean we blast or scrape them. There is always more film to be
scrapped off. The abrasion and malleability of the material leaves a lot to be desired.

Try increasing the potency of your Sodium Hydroxide bath as well as the amount of time you let the models sit. This will help dissolve more of the support material. Just remember to pressure-wash the models again once removing them from bath. It might also help if your using an ultrasonic bath. In addition, Stratasys is aware of this issue and is releasing support for a water-soluble support material with their new line up.

I send my prints to Argen and have had perfect results.My pfz contacts and occlusion are fine . I'm not sure what printer they use .

From receiving their printed models when our machine was down, it seems as if they are using a Projet series printer (3510 maybe) with the Pearlstone (PS200) material. They might be using one of the 3D Systems larger printers as well, but I am fairly confident it is from the Projet line.

 

[rkm rdt]

cool,thanks

 

[Marcusthegladiator CDT]

Tactfully done, Marcus. It's the other skill as a employer or supervisor that sometimes can be taken for granted, that employees etc. may not understand that side of our holding back and diplomatically getting a point across.

I'm neither an owner or supervisor. Just another cook in the kitchen. But it often goes like this.

Me, "Hey you dropped that steak on the floor, you cant serve it, cook another one and fast."
Them, "I think the steak is fine and YOUR not the boss!"

Drives me crazy.

 

[Car 54]

lol..we just can't win either way. In general there seems to be a different mindset of some people, of entitlement, or indifference...of not really caring or thinking about what they do and why...just pay me and feed me, even if the steak fell on the floor.

 

[rkm rdt]

lol..we just can't win either way. In general there seems to be a different mindset of some people, of entitlement, or indifference...of not really caring or thinking about what they do and why...just pay me and feed me, even if the steak fell on the floor.

whatever

 

[Car 54]

That pretty much sums up the attitude.

 

[Edward123]

I ordered 3 3shape articulators from Core3D. At first they were great. But then an assistant across the hall threw two of them away. WTF!
She knew it was ok to toss the 3d models when they were done. But who would think that pretty little CNC machined piece of heavy metal would go in the trash? Idiots. So we had one left, and at $150.00 I didn't want to order more. We still have it. But don't us it.
The models interface fit the 3shape articulator so incredibly tightly. I have to break the capillaries in my fingers to rock them off. Then I watched another idiot take a full size hammer to the articulator to remove the printed casts. As he was denting up the pretty little CNC machined 3 shape articulator. I wanted to scream, "WHAT THE HELL ARE YOU THINKING YOU STUPID BASTARD!." But instead I asked him to please not beat the pretty little $150.00 CNC machined articulator with a hammer.
I was thinking about adjusting the dimensions of the printed casts by 1,2,3% to see if I can dial them in.
I will see how it goes and let you guys know.

That's really too bad but at least they didn't throw out the crowns with them!
BTW... Where are you buying the 3shape articulators for $150? I've only seen them for $200. $210 at Core3D.