Calcium Phosphate Cements: From the 1980s to the 2020s

Over the past four decades, calcium phosphate cements (CPCs) have emerged as promising materials for bone repair due to their biocompatibility, osteoconductivity, and <i>in situ</i> hardening properties. Developed from a combination of calcium phosphate (CaP)-based powder and a liquid phase, CPCs undergo a chemical reaction when mixed, forming a crystalline solid structure at body temperature. This hardening process is characterized by its mildly exothermic reaction, offering significant advantages compared with cements like polymethylmethacrylate, commonly used in orthopedic surgeries. Over more than four decades of research, various modifications have been introduced to the physical, mechanical, and biological properties of CPCs, making them adaptable to a wide range of clinical applications, from craniofacial surgery to bone tissue engineering and drug delivery systems. Despite all the advancements, the widespread clinical use of CPCs still faces significant challenges, such as limitations in mechanical strength, degradation rate, and osteoinductive properties. This article provides a comprehensive historical and technical overview of CPC development from their initial discovery in 1980s to current innovations in formulation, physicochemical, mechanical, and biological properties. It highlights crucial milestones in each decade, covering the evolution of these cements and presenting the challenges that remain until today.