There are many studies of glass-ceramics for application as biomaterials [1]. Glass-ceramics forming apatite as a crystallisation product are promising for restoring and replacing hard tissues in orthopaedics and dentistry, because of the good biocompatibility conferred by the apatite crystal. Recently, apatite-mullite glass-ceramics have been developed based on SiO2-Al2O3-P2O5-Ca0-CaF2 [2-4].'The glasses crystallise to form fluorapatite (FAP) and mullite on appropriate heat treatment. Both the apatite and mullite crystals are needle-like, and interlock to give a high fracture toughness. Magic angle spinning nuclear magnetic resonance spectroscopy (MAS-NMR) has been used to investigate the structures of various P-containing silicate or aluminosilicate glasses [4, 5-9]. There are also MAS-NMR studies of the ciystallisation process [4, 10-11]. In this study, 27A1,29Si, 31P and 19F MAS-NMR analyses are used to characterise the crystallisation of glass-ceramics.
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