Laser sintering vs milling

[Drizzt]

Hi everybody ,

What system do you think has the best results for NP copings , laser sintering or milling ? Thank you .

 

[Slipstream]

We get a great fit with laser sintered NP, some of the early machines were a bit overpowered and not entirely suited to the nature of dental fit, if your thinking of buying a system, remember it's a one trick pony a mill can do a wider range of materials.

 

[Drizzt]

I am thinking about buying the PHENIX PXS DENTAL machine . I have seen that it has great results . The only thing concerning me is the longgevity of it , e.g. a 14-unit bridge will it last in the mouth as long as a bridge milled ? How many years are the laser sintering machines in the dental industry ? The majority of our production is NP , and I can always outsource any other material . Thanks .

 

[Slipstream]

The process in dental has been around since the early days of Lava, although they needed a lot of hand finishing back then.

We are still seeing a fall in NP and Gold with milled Zr climbing every month - still a fair volume but no real growth - mayby 7% annually where Zr climbs 3 -4% most months.

One our our client labs recently reported on a laser sintered NP bridge as having the nicest margins the fitting dentist had ever seen, the dentist does a lot of lecture and training - so I guess he's in a position to know what he likes.

So clearly acceptable fit and if you have big enough market, then worth a try.

 

[charles007]

I called months ago to learn more about sintered NP, my first questions was, can it be sintered down to .2 so there is no metal finishing needed..
NOPE, can't be done, no less than .4
There's no way will I pay for NP and still have to finish the metal. Other than pure cost saving in using cast NP, the only other reason to use NP is the advantage of having more room for porcelain on facial/buccal, being able to design thin connectors, and no marginal creeping/ warpage when firing in oven.
Think I'll pass

Can you mill NP very thin ? that would be my next question

 

[Drizzt]

The process in dental has been around since the early days of Lava, although they needed a lot of hand finishing back then.

We are still seeing a fall in NP and Gold with milled Zr climbing every month - still a fair volume but no real growth - mayby 7% annually where Zr climbs 3 -4% most months.

One our our client labs recently reported on a laser sintered NP bridge as having the nicest margins the fitting dentist had ever seen, the dentist does a lot of lecture and training - so I guess he's in a position to know what he likes.

So clearly acceptable fit and if you have big enough market, then worth a try.

The original idea was to buy a nice big milling machine , and promote zirconium ,and mill in CrCo any big cases , that otherwise I would have to seperate them before casting and after that laser weld them . I am trying to save myself from endles hours laser welding . Then I started considering laser sintering , about 100.000 euros more than the milling machine , but the production is faster and the cost per crown is much cheaper . My zirconium production isn't that large , and if I bought a milling machine I would try to expand that area of our lab . on the other hand withe the sintering machine I can have all my production by the machine , and I could concentrate only at veramics and buil-up .It is a dilemma !

 

[paulg100]

well ive just had a renishaw scanner installed on loan for a while (yes the horrid contact type like the old procera forte, accurate but limited indications, but zero expense to me),to get to the bottom of this DMLS stuff once and for all.

Dentsply and Sirona's stuff was junk the last time i tried it, although this may have been the crappy scan data rather than the DMLS tech.

At least i have a proven and tested scanner tech with renishaw that i have some faith in, as far as accuracy is concerned.

Ill let you know how i get on. needs to be at least as good as cast or its ANOTHER step backwards in quality vs traditional techniques.

Seems to be a growing trend with dental cad/cam from my experiance

More productive - yes

better consistancy - yes (wether consistantly bad or consistantly good)

better quality - a lot of the time, NO.

ill post my findings after i have a few cases behind me.

Oh and their current minimal thickness is .5 so like you say Charles, not very encouraging.

Need to be aiming for .3 really to make this a mainstream alternative. IMOH.

 

[k2 Ceramic Studio]

We sometimes get problems with large/deep implant bridges or hader bars, the system twists the angle of the scan to give it the best path of insertion making the cnc unit need a 30/40 and have even been asked for a 50mm disk, our largest is an 18 in Ti so we get them sintered and the results have been fantastic, best of both worlds.

 

[paulg100]

SIGH!

First few cases with the third laser sintering provider i have tried.



Open margins are eaisily visible by eye so 100+ microns.

Margins seal in some places and are open in others, so its not because the coping isnt seated.

That seams to be about my lot for DMLS. quick frankly its ****e.

Is there ANY! cad/cam metal solution that matches casting.. dosent seem so.

Same way cad/cam glass milling is big step back. Im slowly going full circle here. After 15 years of CAD/CAM im gonna be back to doing everything with traditional methods soon. And people say you need cad/cam to compete..but compete with what?

 

[DMC]

I'm going to take a whack at milling Ti copings. I think SLS is around 100um +/- even though the say it's much finer resolution.

Maybe that could work? What about the new Green state metal that Amann Girrbach is releasing? Sinter in Argon furnace into dense metal??

 

[Drizzt]

I'm going to take a whack at milling Ti copings. I think SLS is around 100um +/- even though the say it's much finer resolution.

Maybe that could work? What about the new Green state metal that Amann Girrbach is releasing? Sinter in Argon furnace into dense metal??

*** do you have further info about the green metal ? The word here in Europe is that it will be released in the early months of 2012 . Imes-icore claims that the material is ready , the problem is with the furnaces , although in their catalogue , they say that they test the material with VITA and they have excellent results . They even show a VITA furnace , I think it is the VITA ZYRCOMAT 6000 MS .

 

[paulg100]

look forward to hearing how you get on with that Scott.

The green metals comming out for Sirona mills to from Dentsply but you know what, i think im done with all this R&D. The Argon furnace is a complete deal breaker for me also + as far as i know its only a base metal (crome cobolt) again, no precious or semi?

Ive seen some stunning fits from straumanns milled Ti, but again, whether it translates into day to day, real world use is another matter.

The Sample DMLS copings i saw were fine, now look at that junk above.

 

[DMC]

I'm sure Zengzhou makes a cheap Argon furnace.

I see one from Wotech for around with a 600x400x400mm work area.

(edit) those are super easy to find and way cheap.
The oven will not be a problem. I found many of them I like.

 

[BobCDT]

The AG green metal is a CrCo alloy. The CrCo thermally matches most PFM ceramic systems, so there is no need to buy additional ceramic powders. I have the AG system in our milling center and expect to get the CrCo early next year.

 

[k2 Ceramic Studio]

Had the Skillbond rep in yesterday and he said the Green state metal that Amann Girrbach is releasing will come in at about £19 a unit, what does it cost to mill grade 2 medical Ti? on an open system 12mm disk £20! less than £1 a unit.

 

[DMC]

The difference is in the life of tool, and units per day out of a mill.

Add that up, and the Ti unit will be around $30

You can probable do 2-3x the amount of units of soft Green metal compared to Hard Material. Then add 5-10x the cost of tooling per unit. More wear and tear on the mill...

I'd imagine that the green metal would be not very thin at time of sintering and would require post manual finishing.
I'm sure I could mill a Ti coping much thinner with crispy sharp edges.

 

[k2 Ceramic Studio]

If it costs £1 in material and a £70 a set for the drill bits we get about 100 units per set at least, then my math puts that in at less than £2 per coping including coolant, I know you have wear and tear but if the mill was designed to do it, then let it do it. No furnace time for sintering Ti wins hands down. OK you will be able to mill more of the green metal due to it milling like wax/plastic but then you have to sinter it. £2 A unit, I think that is fantastic.

 

[DMC]

I don't see many Ti coping for sale for under $30 here in the states.

I think they cost much much more than you realize, otherwise you'd see prices much better than that due to competition. That's not happening. ???

I'm spending over $100k to mill a few Ti copings a day! Let me know if you find a better solution, Mk? That's just for the mill. No CAM, no tools.

 

[k2 Ceramic Studio]

I do a small amount of lab to lab Ti, about 10 units a day, mill it over night so it's free for the Zr in the day. we charge about £50 a unit (just for the coping)but most of it is implant bars. have been milling it for over 6 years and really love the stuff. Great profit margin and the engine just keeps on milling. Think it is such a fantastic mill that I picked a second one up last October from Germany.

 

[Drizzt]

I do a small amount of lab to lab Ti, about 10 units a day, mill it over night so it's free for the Zr in the day. we charge about £50 a unit (just for the coping)but most of it is implant bars. have been milling it for over 6 years and really love the stuff. Great profit margin and the engine just keeps on milling. Think it is such a fantastic mill that I picked a second one up last October from Germany.

What milling machine do you have?