SLM FIT

[Ken Knapp]

Recent 3 unit Noble metal SLM processed bridge does not fit. Individual abutments fit, but does not fit when on bridge.

Overlapping images of STL file and scanned bridge shows that #21 moved distal about 150 microns.

SLM process did not reproduce the sent STl file.

I'm 99.5% all ceramic with 99.5% of zirconia bridges fitting. My first SLM bridge does not fit. I have had singles made without any problem.

Is this a common problem with SLM?

I'm going to have the remake made with a cast process instead.

 

[CoolHandLuke]

let me get this straight: the stl was correctly reproduced and somehow this isn't a scanning error

if you reused the old stl and cast it from wax, what difference would it make?

when a die has shifted during scan it needs rescan. ive even had it where the die was too tall and created error over length.

but to directly answer your question yes many people report internal die seating needs good sandblasting and cleaning when created by slm.

 

[Ken Knapp]

let me get this straight: the stl was correctly reproduced and somehow this isn't a scanning error

if you reused the old stl and cast it from wax, what difference would it make?

when a die has shifted during scan it needs rescan. ive even had it where the die was too tall and created error over length.

but to directly answer your question yes many people report internal die seating needs good sandblasting and cleaning when created by slm.

My grammatical error....The SLM process did not reproduce the sent STL file. The image showing the overlap between the sent STL for fabrication and the scanned fabricated bridge shows a misfit of 150 microns on #21.

 

[CoolHandLuke]

well then. that's interesting.

recently we had a batch of material for casting and had a similar issue; copings seemed to warp in the oven during porcelain building, creating open margins. it was only with one specific alloy though, because once we switched the problem vanished.

i wonder if something similar is happening here. during degauss stage or first wash bake...

is this straight from the manufacturer?

 

[zero_zero]

well then. that's interesting.

recently we had a batch of material for casting and had a similar issue; copings seemed to warp in the oven during porcelain building, creating open margins. it was only with one specific alloy though, because once we switched the problem vanished.

i wonder if something similar is happening here. during degauss stage or first wash bake...

is this straight from the manufacturer?

Never heard that the metal frames need to be degaussed...lol...

 

[Ken Knapp]

well then. that's interesting.

recently we had a batch of material for casting and had a similar issue; copings seemed to warp in the oven during porcelain building, creating open margins. it was only with one specific alloy though, because once we switched the problem vanished.

i wonder if something similar is happening here. during degauss stage or first wash bake...

is this straight from the manufacturer?

Straight from the manufacturer. No adjustment or firing.

 

[cadfan]

SLM deppended on many many things if they have their process under control its 90 percent ok but its not easy different placement,sinter speed, supporters,thickness,form,glow relaxation and so on thats why i am back on the mill better consistence

 

[French Cadman]

Moisture ( humidity ?) in the CoCr powder is also a big problem !
When there is moisture in the room where the powder is stored you need to dry it before use ...

I don't like that, too random, too unpredictable ....

Try to make a customized abutment with SLM , you can't , it's inaccurate !


I prefer my cast !

 

[Drizzt]

I have used SLM with and without problems . I have had wrapping after firing , caused of faulty manufacturers process after the SLM procedure . It needs a firing to relieve the tension .

 

[rkm rdt]

It needs a firing to relieve the tension .

I had a ex boss tell me that once.

 

[user name]

I dont do pfm any more, and SLM helped me quit. They stink.

 

[eyeloveteeth]

we did a ton of SLM copings and they have been fine. 1. Try milling a wax coping and see how it fits. if it's insanely snug, then the SLM bridge will definitely not fit.

#2. Not all SLM machines are created equal, who did you get them from? (if you don't mind divulging)

#3. Frames works are a little bit more tricky, so even less manufacturers right now can do it right. Warp factor is pretty high

#4. scanning tolerances are off? (long shot, but had to ask)

 

[JohnWilson]

Initially there was some struggles but nothing with fit, we had perfect fit from day one. I have done 6 unit bridges with no warp I have done maryland bridges with fits that I never achieved via wax and cast, with wings .4 sandblasted and .3 after polish. I have had really positive results

 

[Andrew Priddy]

I dont do pfm any more, and SLM helped me quit. They stink.

is there some kind of support group for that?
not trying to break your anonymity.. but I may really need one

 

[Ken Knapp]

we did a ton of SLM copings and they have been fine. 1. Try milling a wax coping and see how it fits. if it's insanely snug, then the SLM bridge will definitely not fit.

#2. Not all SLM machines are created equal, who did you get them from? (if you don't mind divulging)

#3. Frames works are a little bit more tricky, so even less manufacturers right now can do it right. Warp factor is pretty high

#4. scanning tolerances are off? (long shot, but had to ask)

The SLM company is XYZ

They are going to remake the bridge with cast process. They said they don't have "many" problems with simple bridges, as mine, to long span bridges.

The SLM technician said something about warp correction of the original design for the SLM process. What is warp correction? Sounds like a nonlinear correction for fabrication.....

I have had about 1-2 zirconia bridges not fit out of ~500 bridges. That's approximately .4% remake for fit.

What is the expected fit remake rate for SLM bridges? The manufacturer did not tell me about their failure rates. Zero does not exist in the real world.

 

[eyeloveteeth]

The SLM company is XYZ

They are going to remake the bridge with cast process. They said they don't have "many" problems with simple bridges, as mine, to long span bridges.

The SLM technician said something about warp correction of the original design for the SLM process. What is warp correction? Sounds like a nonlinear correction for fabrication.....

I have had about 1-2 zirconia bridges not fit out of ~500 bridges. That's approximately .4% remake for fit.

What is the expected fit remake rate for SLM bridges? The manufacturer did not tell me about their failure rates. Zero does not exist in the real world.

Zero in the sense that if it was QC'd properly, they would spot it and get it taken care of

In a N population of 1600+ copings (varying in size and span) - i had a 24 not fit. This was done with Argen.

Sorry to hear that it didn't fit though, I wonder why customer service didn't go further in depth as to what my have caused the problem.

 

[CreDes]

Initially there was some struggles but nothing with fit, we had perfect fit from day one. I have done 6 unit bridges with no warp I have done maryland bridges with fits that I never achieved via wax and cast, with wings .4 sandblasted and .3 after polish. I have had really positive results

John, are you using SLM or DPM... or both?

 

[JohnWilson]

SLM for all normal Noble units anything HN or fg I use dpm . You just can not beat argens flat rate noble price once you work out all the details,


Sent from my iPhone using Tapatalk

 

[Drizzt]

I love SLM . Milled metal is still better of course , but again , SLM is a lot better than casting . I am talking about CoCr . Here in Greece it is so cheap . 7 euros per unit , 24 hours since I send the file and it is back in my lab . No wrapping if the SLM center knows what their are doing . It is all about doing the proper procedure to relieve the tension after sintering .

 

[Affinity]

Im gettin on the train, done casting.. sending Argen some units. Anyone else offering HN SLM?