Improved bone anchorage of hydroxyapatite coated implants compared with tricalcium-phosphate coated implants in trabecular bone in dogs

Citation
M. Lind et al., Improved bone anchorage of hydroxyapatite coated implants compared with tricalcium-phosphate coated implants in trabecular bone in dogs, BIOMATERIAL, 20(9), 1999, pp. 803-808
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
BIOMATERIALS
ISSN journal
0142-9612 → ACNP
Volume
20
Issue
9
Year of publication
1999
Pages
803 - 808
Database
ISI
SICI code
0142-9612(199905)20:9<803:IBAOHC>2.0.ZU;2-J
Abstract
Tricalcium phosphate (TCP) and hydroxyapatite (HA) ceramic coatings are bio active coatings that have been shown to stimulate bone apposition onto cera mic-coated implants. TCP and HA ceramics have well-documented differences i n physical properties, but both types of ceramics are used for stimulation of bone ongrowth to cementless endo-prosthetic components clinically. Howev er, little is known about the difference in osteoconductive properties betw een these coatings when inserted into trabecular bone in a controlled exper imental situation. Unloaded cylindrical gritblasted titanium (Ti-6Al-4V) im plants (6 x 10 mm) coated with either hydroxyapatite (HA) or tricalcium pho sphate (TCP) ceramic were inserted into the proximal humerus of 20 skeletal ly mature dogs. The implants were initially surrounded by a 2 mm gap. Each animal received one HA-coated implant and one TCP-coated implant, All dogs were sacrificed 6 weeks after surgery, Results were evaluated by histomorph ometry and mechanical push-out test. Push-out tests demonstrated that HA-co ated implants were 10-fold stronger fixated in comparison to TCP-coated imp lant. Bone ongrowth was significantly higher for HA-coated implants compare d to TCP-coated implants. Bone volume in the gap showed a tendency to less bone volume around HA-coated implants compared to TCP-coated implants but t his difference was insignificant. As expected almost all of the TCP coating were resorbed after 6 weeks and almost none of the HA coating. HA-coated i mplants with a grit-blasted surface provide a favorable early mechanical im plant anchorage most likely due to superior ceramic stability compared to T CP-coated implants. (C) 1999 Elsevier Science Ltd. All rights reserved.