In-situ synthesis of biphasic calcium phosphate ceramics using microwave irradiation

Microwave synthesis of ceramics offers the advantage of efficient transform ation of energy and heating throughout the volume efficiently in shorter pe riod leading to fine crystallites. Hydroxyapatite (RA) and tricalcium phosp hate (TCP) are widely used in the field of medicine and dentistry. Recently , biphasic calcium phosphate (BCP) ceramics has been paid attention as an i deal bone substitute due to its controlled degradability. In this paper, we report the in situ formation of BCP ceramic consisting of a mixture of HA and beta -TCP in various ratios synthesized under microwave irradiation. Th e BCP powders were characterized by various techniques like DTA, TGA, XRD a nd FTIR. The thermal stability of the BCP powders was determined using diff erential thermal analyser and thermogravimetric analyser. The X-ray diffrac tion pattern of BCP powders shows the in situ formation of beta -TCP in BCP powder. The amount of beta -TCP phase increases as the Ca/P ratio decrease s from 1.67 to 1.52. The Fourier transformed infrared spectroscopy analysis also confirmed the BCP formation. The in vitro solubility study of BCP pow ders in phosphate buffer of pH 7.2 showed the resorbable nature of the BCP ceramics. The present study demonstrates the feasibility of in situ formati on of BCP ceramics using a domestic microwave oven. (C) 2001 Elsevier Scien ce B.V. All rights reserved.