Bone graft engineering: Composite scaffolds

Abstract In recent years, bone tissue engineering techniques have shown great promise for generation of dental bone grafts with highly biomimetic properties. Alveolar bone tissue engineering uses a combination of scaffolds, cells, and/or bioactive factors to generate new bone tissue and, occasionally, other related and interfacial tissue types relevant to the periodontal unit. Given the highly complex environment of the periodontium in which alveolar bone resides, composite scaffold design has been instrumental in producing truly biomimetic scaffolds that can recapitulate the heterogeneous chemical, physical, and biological properties of dental bone. One important aspect of composite scaffold design has been utilizing novel material combinations and composite materials from multiple classes—including synthetic polymers, natural polymers, and ceramics—to provide a myriad of biomimetic features. Building upon this, the emergence of high-fidelity scaffold fabrication techniques in rapid prototyping have enabled the production of complex, spatially defined architectures from these composite materials. Furthermore tissue engineers have utilized multiphasic and gradient scaffold design to directly address the heterogeneity of alveolar bone and its surrounding periodontium. Thus more biomimetic scaffolds and dental bone grafts have been produced by combining composite material selection, high-fidelity 3D scaffold fabrication, and multiphasic scaffold design. Further improvements to dental bone graft engineering can be explored through the development of more precise mechanical, physical, and biological gradients that mimic the periodontal unit.