Abstract:
Much of the efforts have been made over the period to select an appropriate material
for bone implants. Metals such as stainless-steel and Co-Cr alloys with good
toughness were used initially. But, these materials have been faced rejection in long
term fixations due to stress-shielding, corrosion and cell adhesion. Among other
metals, titanium with its amazing set of properties proved to be an ideal candidate for
bone implants. But its elastic modulus and thermal properties still differs from the
bone leading to stress-shielding and oral burn syndrome. The shortcoming of titanium
can be improved either by alloying addition or introduction of porosity.
In this study, microporous titanium implants were prepared by adopting melting
technique. Initially, alloys were developed by using different atomic percentages of
filler element which were then removed by electrochemical dealloying. The result of
this technique was formation of micro-size pores with open morphology throughout
the implant.
Porous metallic structure was developed and characterized successfully. XRD depict
complete removal of filler element which also coincide with the weight loss
calculations. These developed pores in titanium was also observed under SEM
analysis. When the modulus of micro-porous structure was compared with human
bone, it was proved that the presence of pores reduces the modulus without causing
any major effect on the strength of implant. This introduction of porosity in titanium
implants also causes a reduction in value of thermal diffusivity to the level of bone.
Examination of the porous implants for cell proliferation under fluorescence
microscope also observed to be successful that depicts bio compatibility of the
prepared samples.
Samples with porosity level 22%-42% are more suitable as their elastic modulus and
thermal diffusivity becomes equal to the bone. Also, this porosity level supports cell
adhesion process due to the availability of more sites. Thus, these implants are
suggestive to be used for orthopedic and dental applications.
