CoCr full arches, fitting problems etc

[rookiee]

Ok guys, I've got a headache. Aspirin doesn't help, maybe life with budda monks would help.

Problems I've been experiencing are related to fittings with my frameworks. Years we've done it manually but almost every single one was bent. Bad doctor, feather preparation and maybe sometimes I could say it was accetable. Few years later my doctor are giving me nice impressions, shoulder preparation. I've bought D700 and off we go. Started with SLM frameworks but lately I think it's getting worse. Frameworks were bent sometimes, milling center said that only I have these problems. They've spoken with machine manufacterer and I think that they were saying that product is ok and I have to adjust manually framework. Then I found new center, everything was ok but two weeks ago I got upper full arch. Came from machine, try in, everything was ok. I've put opaquer on it and BAM, coulnd't get it on the model, yeah, if I use pure force. The guy from center says, framework has to bi big, big contact point, thick copings etc. This one was really a little big "small", small teeth, no height but can't do anything about it. Or increase VDO for few mm. So I threw it in garbage. Went from SLM to milling. Local milling center returns me framework but all copings were "open". Settings I use were 10 microns on margin and 30 for extra space, starting from 1,5 mm from margin. Another one rejected. They don't know why it happened. They think there are some parameters, they will investigate. Then the same framework was sent to third company, SLM where fitting is ok but the whole framework is bent. Had to straighten it with laser but that's a no deal if you ask me.

So, three companies, two tehnologies, three machines, three operaters, three crapy frameworks. And I can't get it. Thousands of euros of technology and still unreliable. What are you experiences? Both SLM centers are saying that they are giving a framework extra treatment in furnace afterwards. Talking to my friends and of course, nobody has any problems, except one, who uses same company for SLM but has different scanner. I can later post some pictures. Joke is that I don't believe it is scanner. It's regulary calibrated and why the hell it would be if margin nicely follows margin on die and also every single die normaly fits great on framework but all together, the framework is just bent. I also check for undercuts and stuff. So now I wonder, am I crazy or is everyone else sloppy? Oh and all dies are properly seated on the model. Or am I on a bad luck spell and picked wrong centers? Btw, I'm situated in Europe. So yours 50c?

 

[JohnWilson]

I am not a fan of SLM for anything BIG. It is cost effective and great for singles and small bridges with smaller pontics but not for an arch.

As for milled chrome not fitting I am pointing more the scan and design. Just make single dies and pour full arch model and merge in the dies for the design.

Make sure you understand insertion direction and your spacer is appropriate for draw.

IF its warping after you run it up in the oven thats a different thing and the alloy used can have an issue if your parameters are not matching.

Firing opaque high, or with out proper support in the oven can cause some weird things to happen. Chrome is so damn easy to mill clean on the right machine that I doubt the milling center is doing anything wrong.

If they are not giving your a specific DME for their material settings make sure you are matched to their recommendations for margin line offset and spacer.

Good luck

 

[rookiee]

They didn't gave me any specific parameters, just size of a drill. Don't what could be worng with a scan. All three things were done with the same file, three different result. At least I can say SLM framework did close the margin, milled one not. Could be parameters but if they haven't tweaked the system... Pics are from milled framework.

 

[JohnWilson]

That milled frame is ****, do you know if it is true chrome being milled or a "sintron" type of sintered chrome?

Also ask your milling house what other customers are using in with success for the parameters I outlined.

I know I would never send again if I had results like that,

 

[cadfan]

just rescan the produced parts and match with the original file than you have your answer , i would say there are min 20 to 30 percent non precious crap outside and no other has this problem thats BS. I ve shown this so many man u fractures i am tiered about that. Deviation on SLM depended on volume , form , supporters, crown thickness, relaxation glow and the position on the plate. Milling is another story but in general better fit over the distance and depending on the used mill and mill strats bad single fit , if the mill strats are good go for milled parts try dedicam, millhouse, or Mack all germany if in reach.

 

[PDC]

I never liked the milled NP stuff. It never fit worth a crap. I think Strategy milling was supposed to come out with a milled palladium alloy this month. You might give that a shot.

 

[cadfan]

try this with SLM if you can, you get 1000 million USD milling hard stuff is hard stuff milling wax and zircon is for " girls" but hard stuff fit can be nearly the same

 

[2000markpeters]

We mill chrome day in day out on Dyamach DT2 using Sum3d. We use 5 burs to mill out the restorations with perfect results. Your millong judt do not have it dialed in.
Whether we use chrome or titanium same great results.
As far as using sintered chrome we are new to it but achieving great results up to 8 units so far.

 

[2thm8kr]

try this with SLM if you can, you get 1000 million USD milling hard stuff is hard stuff milling wax and zircon is for " girls" but hard stuff fit can be nearly the same

cadfan, do you know what machine that telescope case was milled on?

 

[cadfan]

I think DMG 10 maybe 20 they run no others but the key is incise ( but i although got a lot of crap on DMG 20 from another company)

 

[2thm8kr]

I think DMG 10 maybe 20 they run no others but the key is incise ( but i although got a lot of crap on DMG 20 from another company)

Danke.
You do a lot of telescopic work?

 

[cadfan]

not really a lot telescopes if so i bought a 350 i but this is i as implants a real challenge and i work on a pmma cast solution but the cast pmma s are not real good i have a normal provisional one which is ten times better you feel a few my more cement gap but casting ??!!

 

[rookiee]

That milled frame is ****, do you know if it is true chrome being milled or a "sintron" type of sintered chrome?

Also ask your milling house what other customers are using in with success for the parameters I outlined.

I know I would never send again if I had results like that,

This was real chrome. I just hate and would kill them. Everytime everyone is bragging about their milling center, their work, never seen this before blablablabla. Is everyone soooo undemanding or what? Can realize how can you put something on market with crappy results.

 

[Drizzt]

Where are you located ??

 

[rookiee]

Europe

 

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It's mill, but more Cam strategy, not just step over, but tool selections, it's the design of the cad file, ensuring space for tip radii, so the result you show looks like an accurate scan and machine but internally it's binding suggesting tool deflection and incomplete removal probably at the occlusal internal axial wall area

 

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This is the best mill for money not on the market. e in Taiwan to order. Under 100k and over 2 tonne. It's taken many chromed to nail a strategy that is consistent, and will we tweak each one