TY - JOUR
T1 - Development of hydroxyapatite/calcium silicate composites addressed to the design of load-bearing bone scaffolds
AU - Sprio, Simone
AU - Tampieri, Anna
AU - Celotti, Giancarlo
AU - Landi, Elena
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2009/4
Y1 - 2009/4
N2 - This work deals with the preparation of bioactive ceramic composites to be employed for the development of load-bearing bone substitutes, made of hydroxyapatite (Ca10(PO4)6(OH)2, HA) and bioactive dicalcium silicate (Ca2SiO4, C2S) as a reinforcing phase. The composite materials were prepared by Fast Hot-Pressing (FHP), which allowed the rapid sintering of monolithic ceramics at temperatures up to 1500 {ring operator}C, well above the commonly adopted temperatures for the consolidation of hydroxyapatite (1200-1300 {ring operator}C). The purpose was to achieve the grain coalescence of both HA and the strengthening phase, so that to obtain a homogeneous ceramic material characterized by controlled phase composition and improved mechanical strength; the dwell time was reduced as much as possible to prevent HA decomposition and excessive grain growth. The most remarkable result, in terms of phase composition, was the absence of any secondary phases in the final ceramics other than HA and C2S, even after sintering at 1500 {ring operator}C. The flexure strength of the composite materials was found to be much higher than that of HA alone. Further mechanical characterization was also carried out on HA and composites, sintered in different conditions, to evaluate the elastic properties and fracture toughness, and properties close to those of mineral bone were found. These preliminary results confirmed that composites of HA and Ca2SiO4 are promising for the development of bioactive load-bearing ceramic bone substitutes with controlled phase composition.
AB - This work deals with the preparation of bioactive ceramic composites to be employed for the development of load-bearing bone substitutes, made of hydroxyapatite (Ca10(PO4)6(OH)2, HA) and bioactive dicalcium silicate (Ca2SiO4, C2S) as a reinforcing phase. The composite materials were prepared by Fast Hot-Pressing (FHP), which allowed the rapid sintering of monolithic ceramics at temperatures up to 1500 {ring operator}C, well above the commonly adopted temperatures for the consolidation of hydroxyapatite (1200-1300 {ring operator}C). The purpose was to achieve the grain coalescence of both HA and the strengthening phase, so that to obtain a homogeneous ceramic material characterized by controlled phase composition and improved mechanical strength; the dwell time was reduced as much as possible to prevent HA decomposition and excessive grain growth. The most remarkable result, in terms of phase composition, was the absence of any secondary phases in the final ceramics other than HA and C2S, even after sintering at 1500 {ring operator}C. The flexure strength of the composite materials was found to be much higher than that of HA alone. Further mechanical characterization was also carried out on HA and composites, sintered in different conditions, to evaluate the elastic properties and fracture toughness, and properties close to those of mineral bone were found. These preliminary results confirmed that composites of HA and Ca2SiO4 are promising for the development of bioactive load-bearing ceramic bone substitutes with controlled phase composition.
KW - Calcium silicate
KW - Composite
KW - Flexure strength
KW - Hot-pressing
KW - Hydroxyapatite
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U2 - 10.1016/j.jmbbm.2008.05.006
DO - 10.1016/j.jmbbm.2008.05.006
M3 - Article
C2 - 19627818
AN - SCOPUS:59349116609
VL - 2
SP - 147
EP - 155
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
SN - 1751-6161
IS - 2
ER -