title: The effect of substrate roughness and hydroxyapatite coating thickness on implant shear strength.
abstract: 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-microm-thick HA layer used in the present study provided greater fixation and ongrowth and less resorption compared with the 50-microm-thick layer. We did not observe any advantage in using a thicker HA coating for the titanium substrates examined.
authors.affiliation: Orthopaedic Research Laboratories, University of New South Wales, Prince of Wales Hospital, Sydney, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Svehla
authors.forename: P
authors.initials: P
authors.lastname: Morberg
authors.forename: W
authors.initials: W
authors.lastname: Bruce
authors.forename: B
authors.initials: B
authors.lastname: Zicat
authors.forename: W R
authors.initials: WR
authors.lastname: Walsh
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D017886:Durapatite; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D019736:Prostheses and Implants; D011474:Prosthesis Design; D012756:Sheep; D013499:Surface Properties; D013977:Tibia / Q000601:surgery*; D014025:Titanium
chemical_list: D017886:Durapatite; D014025:Titanium