Bone tissue 3D bioprinting in regenerative dentistry through the perspective of the diamond concept of healing: A narrative review

Abstract

Three-dimensional bioprinting technology appears to be a promising solution for the treatment and reconstruction of a wide range of maxillofacial bone defects. In this review, the authors discuss different bioprinting solutions and options in the context of the 4 factors of bone healing: structures or scaffolds, osteogenic cells, growth factors, and stabilization (diamond concept of healing), as well as the influence of a 5 th factor -vascularization. Bone is a complex tissue; hence, bone bioprinting may require different technical approaches and mixed methods. Ultraviolet (UV) crosslinkable hydrogels, such as gelatin methacryloyl (GelMA), are among the most promising bioinks; they are enhanced by hydroxyapatite or 1-2.5 mm beta-tricalcium phosphate (β-TCP) granules and porous scaffolds with recommended pore sizes greater than 300 µm. The advantages of mesenchymal stem cells (MSCs) are their significant availability, low tumorigenicity, and great potential for differentiation into osteoblasts or endothelial cells (ECs). Although growth factors require advanced delivery systems, they provide excellent improvement in the functionality of printed tissues. A proper vasculature system supplies cells with oxygen and nutrients, removes waste products, promotes osteogenesis, prevents ischemic necrosis, and improves the mechanical properties of bone. With all of these aspects perfectly balanced and working in synergy, the clinical use of bioprinting is only a matter of time.

Evolving Strategies and Materials for Scaffold Development in Regenerative Dentistry

“…The selection of the scaffold design, stem cells, growth factors and environmental conditions suitable for vascularization are key aspects for successful tissue regeneration, which Osypko et al termed the Diamond concept of healing [139]. Several modifications have shown great potential to enhance the scaffold properties, as well as the growth, of stem cells.…”

Allogenic Bone Graft in Dentistry: A Review of Current Trends and Developments

“…dECM can be obtained in the form of a hydrogel, particles, and cell-laid matrix (after recellularization). In addition, it has also been used as a bioink in 3d-bioprinting [6,39,40].…”

“…The last characteristic of an ideal bone graft, osteoconduction, refers to the ability of a material to provide a scaffold for the ingrowth of vessels, osteoblasts, and the host's stem cells. Some authors propose osseointegration, defined as the ability of a 2 of 12 biomaterial to bond chemically to the surface of the host's bone without the intervening fibrous tissue layer, as the fourth fundamental trait [2,4,6,7] Aside from bone regeneration and bone substitute materials, soft tissues can also be augmented using different materials, including autogenous and xenogenic [8]. Bloodderived autogenous materials, such as Plasma Rich in Growth Factors (PRGF), Leukocyte and Platelet-Rich Fibrin (L-PRF), Advanced Platelet-Rich Fibrin (A-PRF) and Concentrated Growth Factors (CGF), are worth mentioning as they can significantly improve healing and are widely used in many fields of modern dentistry [9][10][11].…”

“…Unfortunately their limited availability and possible complications at the donor site after harvesting determine the need for different grafting materials. Despite the widespread appliance of grafting procedures, no other material has osteogenic potential [6,7]. In grafting procedures, clinicians have not only used bone harvested from donors, but also bone substitute materials like hydroxyapatite [16].…”