Biology of Ceramic Bone Substitutes

The human skeleton has the miraculous capacity of healing itself when needed through a cascade known as bone remodeling. However, bone tissue is not able to regenerate itself in case of a broad variety of defects. In these cases, bone substitution is necessary to enable and support the process of bone remodeling. The gold standard for the regeneration of critical-sized bone defects is the transplantation of patient's own bone tissue harvested from another body region. This harvested bone tissue is called an autograft. Due to its donor site morbidity and limited availability, the use of bone tissue harvested from another individual (allografts) or from another species (xenograft) or synthetic materials that are chemically and structurally mimicking to native bone tissue (alloplastic grafts) has been established. This book chapter covers the physiological phenomenon of bone tissue remodeling and the different bone substitute materials (BSMs). The chapter also sheds a light on tissue responses to biomaterials, as well as inflammation in physiological bone tissue healing and inflammation induced by implanted BSMs. Inflammation generally has a negative connotation, but this chapter intends to elaborate on inflammation as an inherent and important process in bone tissue healing.