The calcium phosphate cements (CPCs) based on α-tricalcium phosphate (α-TCP) are highly attractive for use in medicine and odontology, since they have similar chemical and phase composition of mineral phase of bones (calcium deficient hydroxyapatite (CDHA)). However, one of the biggest difficulties for use of this type of cement is its low mechanical strength due to the presence of undesirable phases, such as β-tricalcium phosphate. The route for obtaining α-TCP is at high temperature by solid state reaction, mixing calcium carbonate and calcium pyrophosphate. The aim of this work was to obtain calcium phosphate cements with improved strength, by studying the obtaining of α-TCP at temperatures of 1300, 1400 and 1500°C. The samples were analyzed by crystalline phases, pH, setting time, particle size, in vitro test (Simulated Body Fluid), porosity, density and compressive strength. The results show that the synthesis temperatures influence strongly the phases of powders obtained and the mechanical properties of cement, being unnecessary quenching for obtaining pure α-TCP.
You might also be interested in these eBooks
Info:
© 2012 Trans Tech Publications Ltd. All Rights Reserved
[1]
C. A. Hsu : Termochimica , 157, 392-393 (2002).
Google Scholar
[2]
R. Legeros, A. Chohayeb and A. Shulman: Apatitic Calcium Phosphates: possible dental restorative materials. J Dent Res 61: 343 (1982).
Google Scholar
[3]
W. E Brown and L. C Chow: A New Calcium Phosphate Setting Cement; J Dent Res 62, 672 (1983).
Google Scholar
[4]
ASTM C 266-89 (Standard test method for time of setting of hydraulic-cement paste by Gillmore Needles).
DOI: 10.1520/c0266-15
Google Scholar
[5]
ASTM C20-00 (Standard test method for Apparent Porosity, Water absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick and Shapes by Boiling Water).
DOI: 10.1520/c0020-00r15
Google Scholar
[6]
ASTM F 451-95 (Standard specification for acrylic boné cement).
Google Scholar
[7]
J. L.M. Machado: Desenvolvimento de Cimento Ósseo de Fosfato de Cálcio como Suporte para o Crescimento de Tecido. Mestrado (Dissertação). Porto Alegre (2007). Universidade Federal do Rio Grande do Sul (UFRGS).
DOI: 10.29289/259453942018v28s1059
Google Scholar
[8]
S. V. Dorozhkin: Calcium Orthophosphate Cements and Concretes. Materials. Vols 2, 221-291, (2009).
DOI: 10.3390/ma2010221
Google Scholar
[9]
R. G. Carrodeguas et al.: New approach to the b -> a polymorphic transformation in magnesium-substituted tricalcium phosphates and its pratical implications. Journal of the American Ceramic Society. (2008).
Google Scholar
[10]
L. C. Chow et al.: Injectable calcium phosphate cements: effects of cement liquid on the physical properties of the cement. Innov Tech Med 18 (1997).
Google Scholar
[11]
F. C. M. Driessens et al.: Osteotransductive boné cements, Vols. 212 (Part H), pp.427-435 (1998).
Google Scholar
[12]
L. A Santos : Desenvolvimento de Cimento de Fosfato de Cálcio Reforçado por Fibras para Uso na Área Médico-Odontológica. Doutorado (Tese). São Paulo (2002). Universidade Estadual de Campinas (UNICAMP).
DOI: 10.47749/t/unicamp.2002.226008
Google Scholar