Interface mechanics and histomorphometric analysis of hydroxyapatite-coated and porous glass-ceramic implants in canine bone.
A canine study was performed to make a histological and biomechanical evaluation of the interface between bone and two different bioceramic implants. A newly developed glass-ceramic formed by P2O5, CaO, SiO2, and Al2O3, giving a crystal phase composed of CaP2O6-AlPO4-SiP2O7, was compared to hydroxyapatite (HA) coated Ti-6Al-4V implants. A total of 24 implants were inserted into the femoral condyle of 15 adult female golden retriever dogs weighing 20-25 kg. There was a 12 week follow-up. Implants were examined by mechanical testing, histology, histomorphometry, microradiograpic methods, and EDAX analysis. The ultimate shear strength for the HA-coated implants was significantly higher than in the glass-ceramic group. When these values were related to the histomorphometric measurements, the difference could be explained by the tissue-to-implant contact. The glass-ceramic showed direct contact only with nonmineralized, osteoid bone. The HA-coated implants, however, were integrated into the bone. The study indicated that porous glass-ceramic containing AlPO4 causes local osteomalacia and might not be suitable for clinical purposes.
Nimb
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Department of Orthopedics, University of Copenhagen, Rigshospitalet, Denmark.
Jensen
J S
JS
Gotfredsen
K
K
D000497:Alloys / Q000737:chemistry; D000818:Animals; D016723:Bone Remodeling / Q000502:physiology; D018786:Bone Substitutes; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology*; D002516:Ceramics; D004285:Dogs; D005260:Female; D005269:Femur; D006132:Growth Plate / Q000502:physiology; D006882:Hydroxyapatites; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D016348:Osseointegration; D019736:Prostheses and Implants; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
D000497:Alloys; D018786:Bone Substitutes; D006882:Hydroxyapatites; C031462:titanium alloy (TiAl6V4); D014025:Titanium