Preparation and physical properties of tricalcium phosphate laminates for bone-tissue engineering

This article describes the processing and characterization of tricalcium phosphate (TCP) laminates fabricated by stacking individual TCP sheets for bone-tissue engineering. In particular, the influences of sintering temperature (900, 1000, 1100, or 1200 degrees C) on the physical properties of TCP laminates are discussed. After sintering the TCP laminates, we confirmed from the X-ray diffraction pattern that beta-TCP was transformed to alpha-TCP at a temperature between 1100 and 1200 degrees C. The Vickers hardness value increased with increasing sintering temperature, up to 1200 degrees C. Meanwhile, both flexural strength and modulus increased with increasing sintering temperature up to 1100 degrees C, but decreased massively when the laminates were sintered at 1200 degrees C. Additionally, field-emission scanning electron microscope observation after flexural test showed interlaminar delamination in the TCP laminates sintered at 1200 degrees C, whereas interlaminar delamination was not observed in TCP laminates sintered at 900, 1000, and 1100 degrees C. Accordingly, this explains the massive reduction in flexural properties at a sintering temperature of 1200 degrees C. The results of this investigation indicate that the physical properties of TCP laminates strongly depend upon the sintering temperatures, so that the choice of sintering temperature is an important factor for successful bone-tissue engineering applications of TCP laminates.