Biomedical Engineering Reference
In-Depth Information
bond to the bone. In addition, metal implants may loosen and even
separate from surrounding tissues during implantation. Titanium-
and titanium-based alloys have relatively poor tribological pro-
perties because of their low hardness. One of the methods that
allow the change of biological properties of Ti alloys is to produce a
nanocomposite that will exhibit the favorable mechanical properties
of titanium and excellent biocompatibility and bioactivity of ceramic.
The most commonly used ceramics in medicine are hydroxyapatite,
bioglass, and Al
2
O
3
[7, 34].
Current research on the synthesis of nanoscale metallic and
composite biomaterials, shows that Ti/(Ni-free stainless steel)-HA
nanocomposites posses better mechanical and corrosion properties
than microcrystalline titanium/Ni-free stainless steel [49]. In the
case of Ti-HA nanocomposities, the Vickers hardness also strongly
increases for Ti-20 vol% HA nanocomposites (1030 HV0.2) and
is four times higher than that of pure microcrystalline Ti metal
(250 HV0.2). The corrosion test results indicated that the
microcrystalline titanium possesses lower corrosion resistance and
thus higher corrosion current density in Ringer's solutions. The
result indicated that there was no signiicant difference in corrosion
resistance among Ti-3 vol% HA (
I
C
=
9.06 × 10
-8
A/cm
2
,
E
C
= -0.34 V)
and Ti-20 vol% HA (
I
C
=
8.5 × 10
-8
,
A/cm
2
,
E
C
= -0.55 V) although
there was a signiicant difference in porosity. For this reason, they
are promising biomaterial for use as heavy load-bearing tissue
replacement implants.
The availability of large amounts of speciically tailored
nanostructure Ti-based powders is crucial for the successful
development of new dental implants. The processing of these
nanomaterials and their upscaling to enable industrial use has many
challenges. Those new approaches are the gateway for traditional
industry to nanotechnology and knowledge-based materials, with
positive effects on health issues [1, 29, 45, 53].
1.2 Nanomaterials
One of the irst scientiic reports is the colloidal gold particles
synthesized by Michael Faraday as early as 1857 [18]. By the
early 1940s, precipitated and fumed silica nanoparticles were
being manufactured and sold in the United States and Germany as
substitutes for ultraine carbon black for rubber reinforcements.
