Freeze Casting Of Custom Shaped Skeletal Implants

The enhancement of a highly controllable fabricating technique is vital in producing implantable bone scaffolds suitable for clinical use. Freeze-casting is a novel fabrication technique to process a porous ceramics with different pore channels. The aim of this project was used to design, produce and evaluate porous scaffolds with the different pore architectures by unidirectional freezing of suspensions and sintering at three different temperatures: 1000 °C, 1250 °C and 1375 °C. Freezing of aqueous suspension of hydroxyapatite with ludox solution resulted in the formation of scaffolds with the different discrete and interconnected pore networks. The scaffolds were characterised by the various techniques of X-ray diffraction, optical microscope, scanning electron microscope and finally micro computerized tomography. It was discovered that these techniques characterised the scaffold structural phases, micro structural image of pore sizes in 2-dimensional and 3-dimensional views, and finally, analysed the different morphometric pattern of pores in 3-dimensional technique. It was explicated that these porous scaffolds have transformed from hydroxyapatite to alpha tri-calcium phosphate beyond 1000 °C. The porous structures were evaluated in microscopic slides for different pore networks and eventually, resulted in greater surface area of pores in the three different porous scaffolds. Subsequently, the three distinct scaffolds resulted in different ranges of porosities with53- 61 % and the pore sizes of 100-400µm. Among the three distinct temperatures, transformed scaffolds were displayed with the greater pore sizes and porosity. Finally, it was concluded that tri-calcium phosphate scaffolds produced at 1250 °C and 1375 °C displayed superior pore networks compared with the hydroxyapatite scaffold at 1000 °C. These transformed scaffolds may encourage osteoblastic formation due to the increased pore sizes and increased solubility rate. Therefore, these scaffolds are considered to high excellent potential for the repair of segmental defects in craniofacial reconstruction.