| ULTRACOATŪ - A MAJOR ADVANCE |
The use
of UltraCoat® ceramic titanium nitride (TiN) coating on
articulating surfaces substantially reduces wear and friction.
These low friction and wear properties are of great importance
for successful femoral resurfacing. However, not all titanium
surface treatments are the same. It is imperative to utilize
a coating that has been thoroughly tested. Our research shows
differences processes can result in inferior bearings. UltraCoat®,
through a proprietary, reproducible process, is a thoroughly
tested coating, and is the result of over 15 years of research,
development and clinical evaluation.
TiN
Ceramic Coated Titanium
PVD coated
TiN Ceramic 8-10 microns thick coating hardness, smoothness,
and wetability superior to Co-Cr with superior wear resistance
and greatly reduced polyethylene wear.
A 10 million
cycle simulation of both Co-Cr and TiN shows that wear of
UHMWPe articulated with TiN is one-third the wear with Co-Cr.
The durability of TiN coatings is demonstrated by a 50 million
cycle test of femoral resurfacing components.
Other
advantages of TiN coated titanium are discussed below:
Head
WC, Bauk DJ and Emerson RH, CORR 311, Feb 1995, pp: 85-90
“There
is ample…. clinical evidence to support Ti Al V as the
material of choice for cementless femoral stems based on its
lower modulus of elasticity and…. biocompatibility.”
“Titanium
Aluminium Vanadium alloy is of relatively low toxicity….
and is inert in the physiologic environment.”
“There
is evidence of superior bony ingrowth into Ti Al V as compared
with Co Cr Mo.”
Fare
S, Brossa F, Paracchini L, Cigada A, Severgnini E, Mattavelli
D - Fifth World Biomaterials Congress, Toronto, May 29th –
June 2nd, 1996
“The
purpose of this study was to investigate different surface
treatments on Ti Al V alloy in order to minimize the wear
rate of UHMWPe. Pin on flat wear tests (ASTM F732-82) and
other surface characterisation tests were carried out.”
“Ti
Al V flat discs were treated with different surface modifications:
Zirconium Nitride (ZrN) and Titanium Nitride (TiN) using Physical
Vapour Deposition (PVD) at 450’C.”
CONCLUSIONS:
“Tests demonstrate the good wear resistance of UHMWPe
against Ti Al V bearing surface coated with ZrN or TiN by
PVD. With these surface treatments it is possible to increase
Ti Al V surface quality. Consequently, the wear rate of UHMWPe
decreases significantly when compared to untreated Ti Al V.”
Wisbey
A, Gregson PJ, Peter LM, Tuke M, University of Southampton,
IMechE 1989
“The
application of a thin TiN coating has been shown to significantly
decrease the release of harmful metal ions from CCM surgical
implant alloy. With current concern at the effects of aluminium
and vanadium release from Ti Al V and increasing medical use
of this alloy, a TiN coating may be of benefit, especially
on cementless fixation systems with high implant-tissue interface
areas. Furthermore TiN coating may enhance the wear resistance
of Ti-alloys.”
“The
study sets out to investigate the effect of TiN coating on
the release of vanadium from the Ti Al V substrate together
with the release of titanium from Ti Al V, commercially pure
titanium and TiN surfaces…. The TiN coating was about
two microns thick.”
“Surface
breakdown potentials were determined from potentiostatic polarisation
curves from the various specimens in Ringers solution and
corrosive potentials after 400 hours exposure to Ringers solution
were recorded.”
“The
breakdown potentials determined for Co Cr Mo and Ti Al V are
in agreement with published data. TiN coating increases the
breakdown potential of Co Cr Mo but does not affect the potentiostatic
polarisation response of Ti Al V…. The dissolution studies
reveal a continuous release of vanadium from Ti Al V.”
“The
presence of TiN coating reduces the release of vanadium by
a factor of ten.”
“A
TiN coating on Co Cr Mo provides an excellent barrier to metal
ion release from the substrate.”
Conclusions:
“Vanadium release from Ti Al V is reduced in the presence
of a TiN surface coating.”
“Cobalt
and nickel release from Co Cr Mo is reduced in the presence
of a TiN surface coating.”
“Passivation
treatments influence the metal ion release from TiN, commercially
pure titanium and Ti Al V. These effects are the subject of
further investigation.”
Titanium
nitride PVD ceramic coating on titanium alloy substrate has
a number of unique qualities, as a bearing surface and an
ingrowth surface, that have been demonstrated in laboratory
testing and “in vivo” on Endotec products since
1989.
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