Structural properties

Porosity ^2,16-17

• Refers to the fraction of the volume of voids within the material over the total material volume
• Macro porosity
  • Pores > 100 µm -400 µm
  • Provides a scaffold for bone cell colonization

• Micro porosity
  • Pores < 10 µm
  • Allows body fluid circulation (proteins)
  • Allows blood vessel ingrowth (< 30 µm decreased tissue infiltration

• Surface porosity
  • Pores only on surface area
  • Mechanically stronger

• Interconnective porosity
  • Pores throughout entire structure
  • Mechanical weaker

• Porosity allows for mechanical interlocking between the implant biomaterials and host bone
• Rules of thumb:
  Strength:       Interconnective porosity mechanical weaker compared to surface porosity
  Resorption:  Interconnective porosity resorbs faster compared to surface porosity
  Degradation:Interconnective porosity degrades faster compared to surface porosity