• Petit, Fabrice
• Leriche, Anne
• Thuault, Anthony
• Somers, Nicolas
• Lasgorceix, Marie
• Jean, Florian

Abstract

β-tricalcium phosphate (β-TCP) is one of the most attractive biomaterials for bone repair since it shows an excellent biological compatibility, osteoconductivity, and resorbability. It can be used to produce bone implants serving as temporary supports for bone regeneration.However, there are still some issues for β-TCP porous scaffolds fabrication. Indeed, β-TCP cannot be used as scaffolds in large bone defects or in load-bearing areas due to its weak mechanical properties related to insufficient densification level. Indeed, the sintering temperature is limited because of the occurrence of a phase transition β to α-TCP at 1150°C with a large lattice expansion causing microcracks and reducing shrinkage during sintering. The thermal stability can be increased by the incorporation of dopants inside the β-TCP lattice. Indeed, such dopants like cations can replace the calcium inside the structure and stabilize the β phase as well as improve the biological properties. Thus, cationic substitution can allow reaching higher relative density value. In this work, doped β-TCP powders are synthetized by coprecipitation of Ca(NO3)2 and (NH4)2HPO4 solutions in presence of different cations in order to prevent the phase transformation and increase the sintering temperature. Owing to the β-phase stabilization, new rapid sintering techniques like microwave sintering can be successfully applied with a limited grain growth. The sintered samples are compared in terms of microstructural and mechanical properties. In addition to the sintering and thermal stability study, 3D-printable suspensions are prepared from optimized doped powder to manufacture porous scaffolds by robocasting.

Topics

• porous
• density
• impedance spectroscopy
• grain
• phase
• phase transition
• defect
• Calcium
• biomaterials
• sintering
• densification
• grain growth