**9. Comparison of dentin scaffolds and biomaterials**

Dentin scaffolds are composite materials of organic and inorganic components with natural cross-linking. Active 3D structure can be created in dentin scaffolds by using ultrasonic demineralization method and/or handmade technique under doctor's idea. Collagenous materials and ceramics are commercially available for medical use. Collagenous materials are a single component (mainly type I collagen) or a mix of type I collagen and gelatin. The collagen fibers are derived from bovine or pig. Hydroxyapatite (**Figure 3**), carbonate apatite, and β-TCP are bio-ceramics without growth factors and organic matter (**Table 1**).
