### Properties of an Ideal Scaffold for Bone Regeneration  
Bone is a natural composite consisting of inorganic components, mainly calcium apatite, and organic components, mainly collagen type I. Bone has a complex architecture to withstand diverse mechanical, biological, and chemical functions. The specialized structure involves the complex arrangement of macrostructures (proportion of medullary and cortical bone), microstructures (arrangement of osteons and trabeculae), and nanostructures (collagen fibers and apatite mineral crystals) [4; 5; 15; 16]. Scaffolds are 3D structures that imitate the in vivo environment and stimulate the formation of new tissue [12]. They promote SCs' adhesion, proliferation, and differentiation by creating a suitable microenvironment [13]. Porous scaffolds with optimal 3D architecture serve as artificial bone ECM with osteoconductive properties to promote bone healing. A scaffold should possess good biological properties, including (Table 1):  
* Biocompatibility;
* Mechanical stability;
* Architecture;
* Biodegradability;
* Bioactivity [4; 5; 15; 16]. In order to promote natural bone healing, an equilibrium between the biological properties of the scaffold, osteoprogenitor cells, and signaling molecules must exist [17; 18]. The ideal 3D scaffold for bone regeneration should be composed of a biocompatible, biodegradable material with similar mechanical properties to bone ECM to provide enough mechanical support to the host cells [4; 5; 15; 16]. Scaffolds should mimic the bone ECM to facilitate the osteogenic host cells to deposit natural ECM and replace the scaffold material. Thus, the rate of scaffold resorption should be controlled, complementing host cells' ingrowth. This is particularly important for bone regeneration, where mechanical stability of the scaffold is expected, especially in the load-bearing areas [17; 18]. The 3D architecture of the scaffold should be highly porous with a high index of porosity (number of interconnected pores/mm\({}^{2}\)) to allow for osteoprogenitor cell ingrowth and nutrient migration [19]. The scaffold surface should also be optimized to promote cell attachment, mainly its wettability and roughness. A high number of interconnected pores allows for the diffusion of nutrients and oxygen into the avascular scaffold. The size of the pores is essential, as well as the proportion of nano-, micro-, and macropores in the scaffold. Pores greater than 300 nm promote osteogenesis due to the ingrowth of osteogenicoir cells and angiogenesis [19]. Micro- and nanopores with a size <10 nm increase the scaffold's overall surface, enabling protein attachment and improving cell-scaffold binding. The porous 3D architecture of the scaffold allows for the incorporation of growth factors such as BMPs, vascular endothelial growth factor (VEGF), transforming growth factor \(\beta\) (TGF-\(\beta\)), and insulin-like growth factor 1 (IGF-1) [4; 17]. The most significant advantage of scaffolds is their ease of production, enabling researchers to modify numerous materials and combine them into composite grafts [17; 18; 20]. Thus, it is crucial that the scaffold material allows for easy surgical manipulation and is composed of a material that is adaptive to the individual bone defect. The mechanical properties of the scaffold should be comparable to the compressive strength of the cortical bone (100-250 MPa) to withstand physiological mechanical forces on the bone [20]. Previous systematic reviews of the literature concluded that preclinical in vivo studies demonstrated the clinical potential of scaffolds as an alternative to autogenous bone grafting [21; 22]. [PERSON] et al. [21] performed a systematic review investigating the results of mandibular BTE in animal studies. This review reported a constant increase in the frequency of publications regarding mandibular BTE, reflecting the growing interest in the field.