Bonding strength to titanium

[canack7]

Hi
Does anybody know the bonding strength between porcelain to titanium ?
I am looking for study or research same test was performed in precious, semi precious, non-precious and titanium.
or
let me hear, if some one who is working with titanium pfm for while and see any difference in strength compare to other metal ?

Thanks

 

[Mark Jackson]

Hi
Does anybody know the bonding strength between porcelain to titanium ?
I am looking for study or research same test was performed in precious, semi precious, non-precious and titanium.
or
let me hear, if some one who is working with titanium pfm for while and see any difference in strength compare to other metal ?

Thanks

I have a great deal of experience with titanium and I don't know why anybody would bother with it. The only way we use it is with resin. Part of the problem lies in the reactive nature of the material. At about 600c, the material becomes highly oxidizing. This is generally overcome (or masked) with a bonder, which is really just a glaze. With EVERY firing, the oxide grows and the bond weakens. It is progressive and unpredictable.

The problem is, that porcelain has to fire at well over 600c to vitrify, so you have entered the oxidation zone, and regardless of the bonder, there is still oxidative reactions taking place. With every firing, you build a thicker and thicker oxide, which is called an Alpha Coat. This can show up as a black line at the margin, or yellow migration as the reaction takes place with the ceramics. The titamiun will react with everything in it's environment unless the atmosphere is inert. Vacuum helps, argon backfeed helps even more, but in my opinion, the risks and technique sensitivity are not worth the benefits.

Imagine hot (above 600c) titanium in a porcelain furnace if the vacuum fails, or if the wrong button is accidentally pushed. With regular alloy, you can simply strip and restack. With titanium, you get an implosion, a fireball, and you're buying a new muffle, firing stand, vacuum and possibly a whole new furnace. Ask me how I know?

 

[JohnWilson]

Although I have a very limited experience with this topic we are conduction our own experiments in the lab now with porc to "milled" Ti. We are not seeing any of the issues your reporting Mark.

I know you spent a lot of time energy and money trying to cast Ti, perhaps since you played with the material maybe milled Ti is more predictable.

We have yet to offer this type of unit to my clients, I am just auditioning the product to see its behavior in the lab. So far it is very predictable with no issues what so ever. We have only a few units stacked right now but every real nice model that comes through the lab I am duping and after the first of the year I plan on doing a 50 unit test.

For our European techs that partake on this board I heard this type of restoration is common in Europe is that true? What are your experiences?

 

[Mark Jackson]

Although I have a very limited experience with this topic we are conduction our own experiments in the lab now with porc to "milled" Ti. We are not seeing any of the issues your reporting Mark.

I know you spent a lot of time energy and money trying to cast Ti, perhaps since you played with the material maybe milled Ti is more predictable.

We have yet to offer this type of unit to my clients, I am just auditioning the product to see its behavior in the lab. So far it is very predictable with no issues what so ever. We have only a few units stacked right now but every real nice model that comes through the lab I am duping and after the first of the year I plan on doing a 50 unit test.

For our European techs that partake on this board I heard this type of restoration is common in Europe is that true? What are your experiences?

That implosion above was with milled titanium. I'm giving you the worst case scenerio. The oxide build up happens without you knowing it's there. Depending on the thickness of the ceramic, you may or may not see it, but it's happening. You are not going to change the nature of titanium just by milling it. It is, and always will be reactive. The accident above happened when a regular ceramic cycle was run with a titanium bridge inside. When the high temp was reached and the vacuum released, there was a loud "ffhump" sound from inside the furnace and smoke came out. when the platform lowered, this is what was inside.

It may work out just fine for you John, but it's not very forgiving, so build in some cushion in your pricing to pay for repairs and replacements if something silly happens, which you know will eventually. I woould also suggest you have some strength tests done as part of your 50 unit test.

I posted a question the other day about reimbursement, as we had a titamiun PIB we had to do for a patient who insisted on it. His insurance would only pay for NP, even though I keep hearing people tell me that insurance pays high noble rates. Not ONE insurance company we deal with does!

If you can do PFT for the same price as NP, and still deal with the technicial issues, I'll be impressed.

Hey, I used to be totally against pressing to frameworks, but we are doing it with YZ and after the 1st with PFM's. I've been known to change my tune, but I'm going to let some other people test this one for a long time before I get on that boat again!

 

[JohnWilson]

Its a grey area for reinbursment but truthfully the ADA recognizes Ti as in between Nobel and High Nobel in the CDT book I have.

There is no specific code for Porc fused to Ti in the book I have only for full contour Ti.

 

[Mark Jackson]

Its a grey area for reinbursment but truthfully the ADA recognizes Ti as in between Nobel and High Nobel in the CDT book I have.

There is no specific code for Porc fused to Ti in the book I have only for full contour Ti.

From a biocompatablity standpoint, it's in the right place, but like you say, that has nothing to do with reimbursement. Milling that stuff is time consuming and costly. I charge $380 a unit for it, or $90 a unit for copings.

We did four in all of 2010, and those were last week.

 

[canack7]

Hi Mark and John
Thank you for comment.
I didn't know implosion things.....
I have to see and think many different aspect.

 

[Mark Jackson]

Hi Mark and John
Thank you for comment.
I didn't know implosion things.....
I have to see and think many different aspect.

That why we come to places like this. Doing your due dilligence means hearing the story from every angle. Only then can you make an informed decision.

 

[DMC]

Jeff Saylors in VA is milling titanium and stacking porc.

He loves it. Don't know much else. I know another lab that tried it

years ago, but porc bond failed. Maybe porc. wasn't right back then?

 

[Mark Jackson]

Jeff Saylors in VA is milling titanium and stacking porc.

He loves it. Don't know much else. I know another lab that tried it

years ago, but porc bond failed. Maybe porc. wasn't right back then?

I think the difference in performance has been the development of bonders. The best ones have tin and gold in them, as well as a modified glaze powder, but the oxide layer still exists. The porcelain hasnt changed, and the glaze HAS to be done in air.

Even if people are getting it to stick relaibaly, and the oxide isn't prohibitive, esthetics are. They look terrible. There is a reason it's not being widely done.

 

[doug]

I'm gonna guess that "Press to Titanium" is out of the question, huh? That might be an out since a press and glaze cycle would be just about it for the oxide, except for that nasty burnout. Wasn't Al Tassi having good results with it, Milling and building to Ti

 

[biodentg]

Titanium bond

Perhaps, this article can help...

 

[Mark Jackson]

Pressing is 10000% out! I know Al was using the sintered Ti, but Klapp closed the company down. There is no doubt that titanium has all the great attributes, but so do cast, liquid diamonds and pure platinum. Both of which have some technicial issues to overcome.

I don't know, but I spent over $100k trying to make it work, and I've thrown in the towel. When I can make a zirconia coping for $8, why would I screw around with that stuff?

Just askinn...

 

[Mark Jackson]

Perhaps, this article can help...

Thanks for posting that. I thought I'd seen just about every paper on the subject. Pretty much says it all.

 

[senthildtech]

goog discution for youn technician like me thanks for all

 

[senthildtech]

but some company selling the titanium bonding ceramic, cant we try that? anybody know about that material.