Effect of Ti6Al4V Alloy Surface and Porosity on Bone Osseointegration: In Vivo Pilot Study in Rabbits

Area of Science:

• Biomaterials Engineering
• Orthopedic Research
• Additive Manufacturing

Background:

• Unmodified titanium alloy (Ti6Al4V) exhibits osseointegration capabilities.
• Enhancing osseointegration is crucial for improving implant success rates in orthopedic applications.

Purpose of the Study:

• To evaluate the impact of porosity on the osseointegration of Ti6Al4V implants.
• To compare the osseointegration performance of solid, sintered, and 3D-printed porous Ti6Al4V implants.

Main Methods:

• Three types of Ti6Al4V implants were tested: solid sandblasted acid-etched, sintered, and porous 3D-printed (average pore size 681.00 µm).
• Implants were evaluated in a rabbit femoral condyle defect model over eight weeks.
• Micro-computed tomography (µ-CT) analysis and pull-out testing were performed.

Main Results:

• The solid sandblasted implant showed the highest new bone growth *around* the implant.
• New bone growth *within* the implants was significantly higher for the porous 3D-printed (54.00 ± 5.00 mm³) and sintered (1.00 ± 0.05 mm³) implants compared to the sandblasted ones.
• Pull-out testing revealed significantly greater strength for sintered (900.00 N ± 310.00 N) and porous 3D-printed (700.00 N ± 220.00 N) implants compared to the solid sandblasted implant (220.00 N ± 50.00 N).

Conclusions:

• Porous and sintered Ti6Al4V implants demonstrate enhanced osseointegration compared to solid sandblasted implants.
• Both 3D-printed porous and sintered implants offer comparable and improved mechanical stability over solid implants.
• Porosity is a key factor in improving the osseointegration and mechanical interlocking of titanium implants.