Bone bonding mechanism of beta-tricalcium phosphate.
It has been proposed that the formation of a surface apatite layer in vivo on surface active ceramics is an essential condition for chemical bonding between ceramics and bone tissue. To clarify the difference in bone-bonding mechanisms between surface active ceramics and bioresorbable ceramics, two experiments were performed using plates of dense beta-tricalcium phosphate (beta-TCP). First, plates of beta-TCP were implanted subcutaneously in rats for 8 weeks. Surface change due to bioresorption was observed with scanning electron microscopy. Formation of the apatite layer on the surface was investigated using thin-film x-ray diffraction and Fourier transform infrared reflection spectroscopy. Second, plates of beta-TCP were implanted in tibiae of rabbits for 8 and 25 weeks and subjected to the detaching test to measure bone-bonding strength. beta-TCP bonded strongly to bone. Undecalcified sections of the interface of bone and beta-TCP were examined with SEM-EPMA. However, by physicochemical methods, no formation of surface apatite layer was observed. These results suggest that beta-TCP bonds to bone through microanchoring between bone and rough surface of resorbed beta-TCP.
Kotani
S
S
Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Japan.
Fujita
Y
Y
Kitsugi
T
T
Nakamura
T
T
Yamamuro
T
T
Ohtsuki
C
C
Kokubo
T
T
D000818:Animals; D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; D002516:Ceramics; D008565:Membrane Proteins; D008855:Microscopy, Electron, Scanning; D051381:Rats; D013997:Time Factors; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; D008565:Membrane Proteins; C485817:beta-tricalcium phosphate; C018392:tricalcium phosphate