Replies to post #24326 on SiNtx Technologies Inc (SINT)

[SmokerX]

I`m going to concede on Gill because for all I know he's fully aware of Silicon Nitride biomedical application. TM comes out of the "disruptive tech" pipeline so I`ll concede there too. I`m probably showing anti zimmer bias.

TM in my mind has two advantages. Porous and an attempt at a more bio inert metal then titanium. Silicon nitride seems even better as far as biocompatibility. From what I`m seeing that's the direction that line of research has taken over tanalum. Specifically at kyoto

I`m not adept at reading Weibull modulus data comparing tensile strength of Silicon Nitride vs. Titanium. I don't see anything produced that's easily consumed comparing the two. So I`ll drop this:

https://patentimages.storage.googleapis.com/7c/a8/22/a593c8a47a3451/US5759481.pdf

Despite their enormous potential, advanced structural ceramics in general and silicon nitride in particular have yet to capture many markets, principally due to the perception that they tend toward catastrophic failure, and thus are unsuitable for uses in applications requiring high reliability, While significant progress has been made in the devel opment of strong, tough, refractory ceramics for demanding applications such as the AGT rotor, processing these mate rials sometimes still introduces strength-limiting and reliability-reducing flaws. One measure of the extent of the presence of flaws is the tensile strength of the ceramic.

the Zimmer dental implant looks like its porous tantalum bonded to a Titanium core. Bonding tantalum to Titanium

e (A) included a porous tantalum midsection supported by a threaded titanium body

https://www.zimmerbiometdental.com/en-US/wps/wcm/connect/dental/c26c22f6-949a-427b-a840-9897e0f04cf8/ZD1124+Rev+04-13+Dr_Schlee_Poster.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE.Z18_1O041O02L8PAF0A9JPRUH520H7c26c22f6-949a-427b-a840-9897e0f04cf8

the February 2012 complaint involving an apical tip of a 4.1mm D Trabecular Metal Implant which separated from the implant assembly during surgery on a patient with a dense (Type D1), thick, inferior border.

http://osseotech.com/?p=511

Looks like the problem on this recall was poor bonding of the porous tantalum to the titanium core.

Possibly a factor in brazing? the technology to bond porous silicon nitride to a body of a material with higher tensile strength?

How long to prove the efficacy either way? of the bonding of porous silicon nitride to other materials? the next 20 years? or the biocompatability and inertness of silicon nitride coatings? the FDA needs 20 more years of data or the data on solid sini and porous sini will be ok? I'd think they would need 20 years of data on the bonding relationship of coatings. But does not appear to be the case with the Zimmer tantalum dental implant since they where recalling it for separation. I figure they would have picked up on that in extensive testing before device approval.