Wollastonite - Tricalcium Phosphate Glass-Ceramics of Eutectic Composition Synthesized by the Glass-Crystallization Method. (2nd March 2016)

• Record Type: Journal Article
• Authors: López-Cuevas, Jorge; Pech-Canul, Martín I.; Rendón-Angeles, Juan C.; Rodríguez-Galicia, José L.; Gutiérrez-Chavarría, Carlos A.
• Editors: López-Cuevas, Jorge; Robles Hernandez, Francisco C.
• Is Part Of: MRS proceedings. Volume 1812(2016)
• Publication Date: 2016-03-02
• Subjects: Biomedical, -- Bone, -- Porosity; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/opl.2016.22
• Languages: English
• ISSNs: 0272-9172

Abstract

ABSTRACT: Glass-ceramics of eutectic composition in the wollastonite [W, CaO⋅SiO2 ]- tricalcium phosphate [TCP, β-Ca3 (PO4 )2 ] binary system were synthesized by using the glass-crystallization method. The parent glass was crystalized at 800-1300 °C for 0.5-5 h. The in vitro bioactivity of the synthesized glass-ceramics was tested in Kokubo's Simulated Body Fluid (SBF) for 7-21 days, at pH = 7.4 and 37 °C. All materials were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS). The results showed that metastable Apatite phase [Ap, Ca10 (PO4 )6 O], plus W and TCP phases expected according to the binary phase diagram, were formed. Ap was the first phase formed at 900 °C/0.5 h, which was followed by formation of W phase at 900 °C/2 h and of TCP phase at 1200 °C/0.5 h. The relative proportion of the formed crystalline phases was a function of heat treatment temperature and time. A eutectic microstructure was obtained for the materials heat-treated at 1300 °C for 2 or 5 h. All glass-ceramics showed the formation of a hydroxyapatite (HAp)-like layer during the in vitro bioactivity tests. After 21 days of soaking in SBF, the samples treated at 1300 °C/5 h showed a behavior similar to that typically shown by Bioeutectic ® material, while the materials heat-treated at lower temperatures tended to form denser HAp-like layers, with similar thicknesses but with higher Ca/P molar ratios.