Hydrothermal method for preparing calcium phosphate monoliths

• Autor(a) principal: García Carrodeguas,Raúl
• Data de Publicação: 2003
• Outros Autores: Morejón Alonso,Loreley, García-Menocal,José Angel Delgado, Morejón Alonso,Lizette, Ginebra Molins,María Pau, Martínez Manent,Salvador, Gil Mur,Javier, Toledo Pérez,Jorge, Planell Estany,José Antonio
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Materials research (São Carlos. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392003000300014
• topic: dicalcium phosphate dihydrate; calcium deficient hydroxyapatite; octacalcium phosphate; beta-tricalcium phosphate; calcium phosphate cement; calcium phosphate

A new hydrothermal route for preparing biphasic calcium phosphate monoliths is proposed. Firstly, a slurry of beta-tricalcium phosphate/ortho-phosphoric acid (<FONT FACE=Symbol>b</font>-TCP/H3PO4) is cast into the desired final shape and size to obtain a block composed of dicalcium phosphate dihydrate (DCPD) and <FONT FACE=Symbol>b</font>-TCP. This block is then treated in 1.0 M Na2HPO4 at 60 °C in order to hydrolyze the DCPD into Ca10-x(HPO4)x(PO4) 6-x(OH)2-x (CDHA) and Ca8H2(PO4)6 .5H2O (OCP). The result is a monolithic piece which preserves the initial shape and size, but which is composed instead of CDHA, OCP, and <FONT FACE=Symbol>b</font>-TCP. During the initial stage, when the pH is slightly alkaline, the product of DCPD hydrolysis is CDHA. However, when a neutral or slightly acidic pH is reached OCP is formed. Test samples processed by this method showed complete conversion of DCPD into CDHA and OCP after 112 h of hydrolysis, and with a compressive strength of 16.2 MPa, similar to cancellous bone.