Abstract
Bone defects caused by trauma, infections, neoplasms, and other conditions are commonly treated with autologous grafts, which are considered the gold standard due to their osteoinduction, osteoconduction, and osteogenesis properties. However, their use has limitations, including limited availability, donor-site morbidity, and increased surgical time. Alternatively, allogeneic grafts, xenografts, and synthetic bone substitutes, including ceramics, bioglasses, resins, and metals, have been developed and are often modified with osteoinductive elements, such as growth factors and bioinorganic ions. The ideal bone replacement should be biocompatible, bioabsorbable, mechanically resistant, porous, and capable of promoting osseointegration. Although synthetic substitutes have advanced, they have not yet achieved the effectiveness of autologous grafts, especially concerning osteointegration and economic viability. However, innovations in molecular biology, bone proteins, and gene therapies offer promising prospects for the development of new biomaterials. The current article introduces the reader to bone substitutes by presenting a classification of the materials used and the main characteristics of each group.