$1900/oz Gold! The end is near!

[ed 3]

:yo:

 

[disturbed]

IMO, e.max full press molars way better than Zirconia. In many ways ....E.max softer material than Zirc , do not hit opposing. I made some emax crowns for my wife two years ago and loving it!

In our lab we make mostly e.max

:congrats:

 

[pdent]

Titanium

What does everyone think of Titanium?

 

[TECHARTISAN]

What does everyone think of Titanium?

Titanium in the original context of this thread or as a dental material? I only ask because its economic impact is fairly minimal....but a discussion of the material cost trends would be relatively relevant....

If you were rather asking about it as a dental material.....much like the emax/zirconia derailment....it would be a matter for a different thread...though perhaps more interesting than the market trend analysis

 

[amadent]

What does everyone think of Titanium?

I think alot of doc's and labs are both still leary of it - even thought the milled is better then the cast was- but you still have to get the bonder just right

We used to cast Ti with wieland casting system and layered the Tri-ceram porccelain
maybe it has improved but we had many bond faliures
like this one-


Greg Amendola MDT

 

[amadent]

sorry here is pic

 

[CoolHandLuke]

that guy took a baseball bat to the head. thats not some "porcelain failure".

 

[amadent]

that guy took a baseball bat to the head. thats not some "porcelain failure".

wrong- lost this account due to the "not " porcelain failure and many other just like it- also loves to gas up from the sub structure- i will look to see if we have other bridges laying around

 

[CoolHandLuke]

well i'm not a ceramist, that sure looks like the end result of a severe fisticuffs.

 

[TECHARTISAN]

wrong- lost this account due to the "not " porcelain failure and many other just like it- also loves to gas up from the sub structure- i will look to see if we have other bridges laying around

Out of random curiousity....also not a ceramicist....When you fire porcelain over titanium....Do you fire in an argon atmosphere? or vacuum?

 

[amadent]

Out of random curiousity....also not a ceramicist....When you fire porcelain over titanium....Do you fire in an argon atmosphere? or vacuum?

at the time we were told to fire under vacum this was about 10 years ago not sure if it is still the same

 

[CoolHandLuke]

from what i understand (doing a quick googling) Titanium surface finish must be 100% perfect before it is bonded to any substance (i.e. welding or other forms of fusion) else it runs the risk of "flaking"

if the picture above was a porcelain failure that could be your key. especially if you say it "gassed up" via the substructure.

 

[TECHARTISAN]

at the time we were told to fire under vacum this was about 10 years ago not sure if it is still the same

What CHL, is refering to below is partially where my question came from....again I dont work in ceramic but I have NONDental experience in titanium casting.

Surface finish on titanium is not only critical for bonding purposes but the expediency in handling is also critical as you have little time before the alpha case regenerates...

When you fired under vacuum....was the metal introduced into a preheated furnace then vacuum was drawn? or was the piece placed in a cool chamber, vacuum, then heat? Again I have no experience in dental ceramics....merely brainstorming the potential issues...also...after prepping the titanium...is any coating applied to inhibit oxide formation when doing your "build"? Thermal deterioration of your alpha casing is the only reason you would be experiencing "off gassing".

from what i understand (doing a quick googling) Titanium surface finish must be 100% perfect before it is bonded to any substance (i.e. welding or other forms of fusion) else it runs the risk of "flaking"

if the picture above was a porcelain failure that could be your key. especially if you say it "gassed up" via the substructure.

 

[amadent]

from what i understand (doing a quick googling) Titanium surface finish must be 100% perfect before it is bonded to any substance (i.e. welding or other forms of fusion) else it runs the risk of "flaking"

if the picture above was a porcelain failure that could be your key. especially if you say it "gassed up" via the substructure.

yes you are correct - and perefect means perfect- very time consuming
i tired to upload pdf file - didnt work

 

[amadent]

After sandblasting, a resting time of 10 minutes in air is necessary to allow the surface oxide to form. Do not wait
for longer than 30 minutes before applying the bonder.

Important! Do not overheat the cast framework
during grinding. Avoid red heat and cool well with
water. Do not tilt the separating disk.

 

[TECHARTISAN]

yes you are correct - and perefect means perfect- very time consuming
i tired to upload pdf file - didnt work

Doesnt necessarily have to be time consuming....blaster, etch in hydrofluric acid or comparable etchant....problem is...if you arent working in argon, or immediately applying a sealing agent....youve got 1-3 effective minutes before you are starting over again.

 

[TECHARTISAN]

After sandblasting, a resting time of 10 minutes in air is necessary to allow the surface oxide to form. Do not wait
for longer than 30 minutes before applying the bonder.

Important! Do not overheat the cast framework
during grinding. Avoid red heat and cool well with
water. Do not tilt the separating disk.

AHA.....
I would assume that allowing an oxide layer (alpha case) to form would be a negative as that is where the "gassing" comes from.

 

[amadent]

Doesnt necessarily have to be time consuming....blaster, etch in hydrofluric acid or comparable etchant....problem is...if you arent working in argon, or immediately applying a sealing agent....youve got 1-3 effective minutes before you are starting over again.

Never immerse titanium frameworks into hydrofluoric
acid as this severely corrodes titanium.Never immerse titanium frameworks into hydrofluoric
acid as this severely corrodes titanium.
2.1.2. Trimming and grinding titanium
framework
Important! Do not overheat the cast framework
during grinding. Avoid red heat and cool well with
water. Do not tilt the separating disk.

from tri-ceram pdf file

you also have to let frameworks sit for 10 minutes after blasting but only have up to and no exceeding 30 minutes to place bonder

 

[TECHARTISAN]

Never immerse titanium frameworks into hydrofluoric
acid as this severely corrodes titanium.Never immerse titanium frameworks into hydrofluoric
acid as this severely corrodes titanium.
2.1.2. Trimming and grinding titanium
framework
Important! Do not overheat the cast framework
during grinding. Avoid red heat and cool well with
water. Do not tilt the separating disk.

from tri-ceram pdf file

you also have to let frameworks sit for 10 minutes after blasting but only have up to and no exceeding 30 minutes to place bonder

hmm very interesting...
dip etching with hydrofluoric, is a common method of alpha case removal industrially.....Im not sure I would agree with the characterization of its action as "severely corroding" though in untrained hands I can understand the literatures over dramatization.
I can only assume that the "bonder" must be scavenging oxygen in a reaction with the alpha casing..acting, at least as part of its function, as an etchant...otherwise allowing alpha case regeneration would make no sense at all.
The 10 minutes but not more than 30 could imply that beyond a specific time the expected amount of alpha casing would be too much for the bonding agent to react properly...leaving residual oxides trapped beneath....

In which case...the imprecision introduced by other variables....temperature, humidity, degradation of the bonding agents active ingredient....could affect the 10-30 minute window adversely...resulting in left over oxides....which would breakdown in your firing resulting in the outgassing youve described...

of course, this is all speculative...but interesting nonetheless

 

[disturbed]

titanium, like zirconium, does not oxidize and therefore has NO CHEMICAL BOND... unless supported very well with metal collars, full arch models to show functional issues, and protection from sheer it is likely to de-bond..

bonder layer,,lol...their is no bond except for mechanical retention..same as Zr..layering to Ti is ,in my opinion, a bad idea..I suppose full contour Ti is next.../facepalm

unfortunately I think palladium is the next best thing.. even though it has an affinity for carbon , carcinogenic, and margin creep.

will someone please discover how to turn lead into gold...