TRANSMISSION ELECTRON-MICROSCOPY OBSERVATIONS AT THE INTERFACE OF BONE AND 4 TYPES OF CALCIUM-PHOSPHATE CERAMICS WITH DIFFERENT CALCIUM PHOSPHORUS MOLAR RATIOS
T. Kitsugi et al., TRANSMISSION ELECTRON-MICROSCOPY OBSERVATIONS AT THE INTERFACE OF BONE AND 4 TYPES OF CALCIUM-PHOSPHATE CERAMICS WITH DIFFERENT CALCIUM PHOSPHORUS MOLAR RATIOS, Biomaterials, 16(14), 1995, pp. 1101-1107
Four kinds of calcium phosphate ceramics, beta-calcium pyrophosphate (
Ca2P2O7), beta-tricalcium phosphate (Ca-3(PO4)(2)), hydroxyapatite (Ca
-10(PO4)(6)(OH)(2)) and tetracalcium phosphate (Ca-4(PO4)(2)O), were p
repared, The calcium/phosphorus molar ratios were 1,1.5, 1.66 and 2, r
espectively. Particles (150-300 mu m) of these ceramics were packed in
to holes (diameter 2.5 mm) made in the tibial metaphysis of mature mal
e rats. At 2 weeks, 4 weeks, 8 weeks and 6 months after the operation,
undecalcified specimens were prepared. Transmission electron microsco
py showed that the bone-bonding behaviour of calcium phosphate ceramic
s at the interface with bone did not vary with the calcium/phosphate m
olar ratio. Amorphous substances or needle-like microcrystals were obs
erved on the surface of the ceramics at 2 weeks after implantation. Th
e ceramics showed direct continuity with small crystallites of bone ti
ssue at 4 weeks, 8 weeks and 6 months after implantation. The ceramics
appeared to be getting smaller with time. Collagen fibres were not ob
served at the bone/ceramic interface. Neither chemical bonding nor mec
hanical bonding by interlocking between bone and ceramics was describe
d by morphological observation using transmission electron microscopy.