Tailoring the Surface Functionalities of Titania …
515
4 Surface Modification for Titanium Implants
The selection of right biomaterial for a specific biomedical application relies on the
bulk properties of biomaterial such as corrosion resistance, non-toxicity, controlled
degradability, modulus of elasticity and fatigue strength. After implantation, a
sequence of local events such as classic foreign body response and fibrous tissue
capsule formation occurs around the implant [15]. The biomaterial surface act as a
major influencing factor for the above said unfavorable reactions of the body, as the
initial contact of the body is with the surface [16]. Despite many advantageous properties, Ti-based alloys are poor in bioactivity, as they cannot bond directly with bone
due to fibrous encapsulation and promote new bone formation on the surface at the
initial stage after implantation [17]. Successful implantation of titanium implants
lies in demonstrating excellent osseointegration at the bone-implant surface and
hence it is essential to improve the tissue bonding properties of titanium implants.
The schematic representation of the successful implantation procedure is shown in
Fig. 1(A). The direct contact between the bone and implant Fig. 1(A)–c is essential
for successful implantation procedure. The formation of fibrous tissue can start a
vicious cycle of micromotion and inflammation around the implant surface, which
isolates implanted material from the surrounding bone and finally leads to implant
failure [18, 19].
The surface chemistry and structure of the material are the two essential factors
determining the interactions of the material with the neighboring tissue. Also, it
is evident that the extend of osseointegration and the response of titanium-based
biomaterials depend entirely on its biocompatibility and surface properties [21].
Hence various surface modifications such as mechanical, physical, chemical, electrochemical or biochemical modifications [22–31] are considered at improving the
osseointegration property of the implant surface. The proper surface modification
method not only retains the excellent bulk features of titanium and its alloys, but also
improves specific surface properties required for diverse clinical applications [27].
5 Nanoscale Surface Modification-Formation of TiO 2
Nanotubes
The exploit of nanostructured materials has been proposed to resolve some of
the problems presently associated with implants. As the modified coated surfaces
obtained from various surface modification techniques are not reliable for long
period due to the relatively higher micrometer level thickness and poor adhesion
of the coated layer to the substrate [32], fracture and delamination occur at the boneimplant interface. The length scale of the hierarchical structure of the tissue must be
considered, while designing a synthetic material which is intended to efficaciously
replace living tissue in an organism [33]. The whole length scale from the nanoscale
up to macroscale needs to be taken into account. The interactions between the bone
515
4 Surface Modification for Titanium Implants
The selection of right biomaterial for a specific biomedical application relies on the
bulk properties of biomaterial such as corrosion resistance, non-toxicity, controlled
degradability, modulus of elasticity and fatigue strength. After implantation, a
sequence of local events such as classic foreign body response and fibrous tissue
capsule formation occurs around the implant [15]. The biomaterial surface act as a
major influencing factor for the above said unfavorable reactions of the body, as the
initial contact of the body is with the surface [16]. Despite many advantageous properties, Ti-based alloys are poor in bioactivity, as they cannot bond directly with bone
due to fibrous encapsulation and promote new bone formation on the surface at the
initial stage after implantation [17]. Successful implantation of titanium implants
lies in demonstrating excellent osseointegration at the bone-implant surface and
hence it is essential to improve the tissue bonding properties of titanium implants.
The schematic representation of the successful implantation procedure is shown in
Fig. 1(A). The direct contact between the bone and implant Fig. 1(A)–c is essential
for successful implantation procedure. The formation of fibrous tissue can start a
vicious cycle of micromotion and inflammation around the implant surface, which
isolates implanted material from the surrounding bone and finally leads to implant
failure [18, 19].
The surface chemistry and structure of the material are the two essential factors
determining the interactions of the material with the neighboring tissue. Also, it
is evident that the extend of osseointegration and the response of titanium-based
biomaterials depend entirely on its biocompatibility and surface properties [21].
Hence various surface modifications such as mechanical, physical, chemical, electrochemical or biochemical modifications [22–31] are considered at improving the
osseointegration property of the implant surface. The proper surface modification
method not only retains the excellent bulk features of titanium and its alloys, but also
improves specific surface properties required for diverse clinical applications [27].
5 Nanoscale Surface Modification-Formation of TiO 2
Nanotubes
The exploit of nanostructured materials has been proposed to resolve some of
the problems presently associated with implants. As the modified coated surfaces
obtained from various surface modification techniques are not reliable for long
period due to the relatively higher micrometer level thickness and poor adhesion
of the coated layer to the substrate [32], fracture and delamination occur at the boneimplant interface. The length scale of the hierarchical structure of the tissue must be
considered, while designing a synthetic material which is intended to efficaciously
replace living tissue in an organism [33]. The whole length scale from the nanoscale
up to macroscale needs to be taken into account. The interactions between the bone