SEM-EPMA observation of three types of apatite-containing glass-ceramics implanted in bone: the variance of a Ca-P-rich layer.
The progressive changes of a Ca-P-rich layer between bone and three types of apatite-containing glass-ceramics of the same chemical composition: MgO 4.6, CaO 44.9, SiO2 34.2, P2O5 16.3, CaF2 0.5 (in weight ratio) were examined. Plates (15 mm X 10 mm X 2 mm, mirror surface) containing apatite (35 wt%) (designated A-GC), apatite (35 wt%) and wollastonite (40 wt%) (designated A.W-GC), and apatite (20 wt%), wollastonite (55 wt%), and whitlockite (15 wt%) (designated A.W.CP-GC) were prepared. They were implanted into the tibia of mature male rabbits for 5 days, 10 days, 20 days, 30 days, 60 days, 6 months, and 12 months. All three types of glass-ceramics showed direct bonding to the bone 30 days after implantation. It was observed by SEM-EPMA 30 days after implantation that Si and Mg content decreased, P content increased, and Ca content did not change across the reactive zone from the glass-ceramics to bone. The level of P and Si in the A.W.CP-GC changed five days after implantation. In A.W-GC and A-GC, a little change in P and Si levels was observed between 10 and 20 days after implantation. The width of reactive zone was narrowest with A-GC, wider with A.W-GC, and widest with A.W.CP-GC. The dissolution of glass-ceramics stopped 6 months after implantation. This phenomenon shows that the glass-ceramics may be suitable for clinical use.
Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University.
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Kitsugi
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Nakamura
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Yamamura
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Kokubu
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Shibuya
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Takagi
D000818:Animals; D001031:Apatites / Q000009:adverse effects*; D001672:Biocompatible Materials; D001842:Bone and Bones / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism; D002516:Ceramics / Q000009:adverse effects*; D008297:Male; D008855:Microscopy, Electron, Scanning; D010758:Phosphorus / Q000378:metabolism; D011817:Rabbits; D014465:Ultrasonics
D001031:Apatites; D001672:Biocompatible Materials; D010758:Phosphorus; D002118:Calcium