title: Comparison of hydroxyapatite and hydroxyapatite tricalcium-phosphate coatings.
abstract: This study compared the effects of hydroxyapatite (HA) coating and biphasic HA/tricalcium-phosphate (HA/TCP) coating on the osseointegration of grit-blasted titanium-alloy implants. Each coated implant was compared with uncoated grit-blasted implants as well. The implants were press-fit into the medullary canal of rabbit femora, and their osseointegration was evaluated 3 to 24 weeks after surgery. The coated implants had significantly (P<.05) greater new bone ongrowth than the uncoated implants (HA, 56.1 +/- 3.1%; HA/TCP, 53.8 +/- 2.6%; uncoated, 32.2 +/- 1.4% of the implant perimeter, 12 weeks). Unmineralized tissue (cartilage and osteoid) was seen on the uncoated implants but never on the coated implants. The coated implants had significantly (P<.05) greater interfacial shear strength than the uncoated implants (HA, 4.1 +/- 0.4 MPa; HA/TCP, 4.8 +/- 0.5 MPa; uncoated, 2.6 +/- 0.2 MPa, 12 weeks). There was no difference between HA and HA/TCP coating in regard to new bone growth or interfacial shear strength. These data show a comparable enhancement effect of HA and HA/TCP coatings on the osseointegration of titanium-alloy implants.
authors.affiliation: Department of Orthopaedics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA. jinno.orth@tmd.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Jinno
authors.forename: Dwight T
authors.initials: DT
authors.lastname: Davy
authors.forename: Victor M
authors.initials: VM
authors.lastname: Goldberg
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D017886:Durapatite / Q000627:therapeutic use*; D008297:Male; D016348:Osseointegration; D019736:Prostheses and Implants; D011817:Rabbits
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite