Biomimetic deposition of calcium phosphate minerals on the surface of partially demineralized dentine modified with phosphorylated chitosan.

The aim of this study is to remineralize partially demineralized dentine sections using phosphorylated chitosan (P-chi) based on mimicking the nucleating role of the phosphorylated noncollagenous proteins in the biomineralization of dentine. The surface of partially demineralized dentine sections, mainly composed of type I collagen, were modified by covalent immobilization of P-chi on the collagen surface. The dentine sections were subsequently put into remineralizing solution for remineralization, and then the remineralizing effect was investigated. The remineralization effect of this methodology was compared with that of fluoride. Moreover, the influence of surface properties of samples on remineralizing effect was investigated. The experimental results indicated that the effect of fluoride on remineralization of dentine was limited when residual crystals were lacking on the surface of partially demineralized dentine, whereas the covalent immobilization of P-chi can significantly induce deposition of calcium phosphate minerals on the surface of the partially demineralized dentine. This biomimetic methodology resulted in favorable surface properties (i.e., highly negative charge and low interfacial free energy between substrate and remineralizing medium) for crystal nucleation. Thus, P-chi can facilitate surface remineralization of dentine and thereby could find application in the minimally invasive management of dentine caries and dentine hypersensitivity.