Application of dentin in bone tissue engineering

Defects in oral hard tissue caused by various factors have a negative impact on the functional and aesthetic results of prosthetic treatment. In recent years, the usage of bone tissue engineering for bone reconstruction has drawn widespread attention. Bone tissue engineering exhibits significant advantages, including the abundance of building materials and few side effects. In this paper, the composition and structure of dentin and its application in bone tissue engineering are reviewed, providing a new way to further optimize its performance. The results of a literature review show that the structure of dentin is very similar to that of autogenous bone. The inorganic component is mainly hydroxyapatite (HA), while the organic component is mainly collagen Ⅰ, noncollagenous proteins (NCPs) and growth factors. Because of its unique composition, dentin can act as a scaffold and/or growth factor source through different processing methods. The deproteinization process removes most of the organic substances and creates a HA-based scaffold material with high porosity, which allows for vascularization and cellular infiltration. Demineralization increases dentin porosity by reducing the crystallinity of the mineralized components, so that part of HA, collagen fibers and growth factors are preserved. Demineralized dentin possesses various regulation functions ranging from differentiation, adhesion and proliferation of primitive cells and bone forming cell lineage. Extracted NCPs, as bioactive molecules, have been proved to play important roles that control cell differentiation, crystal nucleation and mineralization in bone formation. NCPs could be combined with variety of scaffold materials and modify their properties.