High-Density Hydroxyapatite/β-TCP composites for bone substitutes - physicochemical and mechanical properties

Biphasic calcium phosphate (BCP) ceramics, composed of different ratios of hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), have been widely used in bone applications mostly due to their similarity to natural bone and their adjustable balance between mechanical integrity and biodegradability. The present work investigates the mechanical performance of highly dense BCP composites with HAp/β-TCP weight ratios of 75/25 and 50/50, produced by hot pressing. Comprehensive physicochemical and mechanical characterizations were performed, including porosity, dissolution behavior, surface roughness, wettability, microstructure analysis by SEM, Vickers microhardness, and flexural strength testing. The 50/50 BCP showed higher density and hardness, whereas the 75/25 BCP demonstrated superior flexural strength, due to its finer grain size. The findings reveal that mechanical properties of BCPs can be effectively tailored by adjusting the HAp/β-TCP ratio, enabling the design of bone substitutes with customized performance for specific clinical needs.