Title of article :
Hydroxyapatite—alumina composites and bone-bonding
Author/Authors :
J. Li، نويسنده , , B. Fartash، نويسنده , , L. Hermansson، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 1995
Pages :
6
From page :
417
To page :
422
Abstract :
Hydroxyapatite-alumina (HA/Al2O3) composites, with HA contents of 15, 25, 30 and 70, and pure HA as well as pure Al2O3, were densified at 1275 ° C at a top pressure of 200 MPa for 2h, using glassencapsulated hot isostatic pressing. From the sintered ceramics, cylinders 2.8 × 6 mm2 were prepared by ultrasonic machining and implanted into the femoral cortical bones of 12 New Zealand White rabbits for 3 months. After killing the animals, the femur was dissected out and cut into three sections, each containing one cylinder. The specimens were mounted in a push-out device and force was applied along the long axis of the cylinder. The maximum force required to loosen the implant was recorded and the fracture surface of the bone implant was studied by scanning electron microscopy (SEM). The results indicate the important role of HA in new bone apposition to the implants, reflected by increasing bonding strength with increasing HA content in the composites. However, the relationship between HA content and the bonding strength was not linear. The composite with 70% HA and the pure HA ceramic had the same level of bonding strength and similar fracture interfaces in SEM, which supports the high bonding strength detected (about 15 MPa). Fractures occurred both in the bone and in the implant, indicating the stress transfer ability of the contact zone. This study presents qualitatively and quantitatively HA-dependent characteristics in bone-bonding. The mechanical strength of the composites was measured by a three-point bending test. The bending strength of the materials decreases with increasing HA content.
Keywords :
Composite , Hydroxyapatite , Bonding strength , alumina
Journal title :
Biomaterials
Serial Year :
1995
Journal title :
Biomaterials
Record number :
542227
Link To Document :
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