Alkali-free bioactive diopside-tricalcium phosphate glass-ceramics for scaffold fabrication: Sintering and crystallization behaviours

摘要

The sintering and crystallization behaviours of alkali-free bioactive glass compositions designed in the diopside (CaO center dot MgO center dot 2SiO(2))-tri-calcium phosphate (3CaO center dot P2O5) binary join by varying the Di/TCP ratios were investigated by hot-stage microscopy and differential thermal analysis, respectively. The effects of non-isothermal heating for 1 h at 900, 1000 and 1200 degrees C on the structural changes were assessed by solid-state magic angle spinning nuclear magnetic resonance (MAS-NMR) and crystalline phase assemblage. The influence of the heat treatment temperature on 3 point bending strength was also investigated. Diopside and hydroxyapatite formed as primary crystalline phases, accompanied by calcium silicate as secondary phase, in samples are sintered at 900 degrees C and 1000 degrees C. With further increase of the heat treatment temperature to 1200 degrees C, whitlockite that was stated appearing in some compositions at 1000 degrees C, appeared as main crystalline phase after diopside as a result of hydroxyapatite transformation. The data gathered was highly relevant towards setting the experimental conditions required for preparing well sintered and mechanically strong glass/glass-ceramic scaffolds for bone regeneration and tissue engineering applications. (C) 2015 Elsevier B.V. All rights reserved.