This study examined the role of substrate preparation and hydroxyapatite (HA) coating thickness on bone ongrowth and shear strength in a bilateral bicortical sheep model. Plasma-sprayed and grit-blasted titanium implants with different thickness HA coatings were examined at 4, 8, 12, and 26 weeks after implantation. Shear strength increased with time for all implants. Plasma-sprayed implants were superior to grit-blasted implants at all time points. The 100-μm-thick HA layer used in the present study provided greater fixation and ongrowth and less resorption compared with the 50-μm-thick layer. We did not observe any advantage in using a thicker HA coating for the titanium substrates examined.
- Hydroxyapatite (HA)