Electrospun mats of PVP/ACP nanofibres for remineralization of enamel tooth surfaces

The inorganic component of dental hard tissues consists of crystalline hydroxyapatite (HAP) and has been the focus of extensive studies in biomineralization. Dental enamel is exposed to constant demineralization and remineralization within the oral environment, and an imbalance between these processes can result in the conditions of dental erosion or dentine hypersensitivity, or both. This study demonstrates the novel use of electrospun mats of amorphous calcium phosphate (ACP)/poly(vinylpyrrolidone) (PVP) nano-and micro-fibres as hydrogel mats that guide and promote in vitro remineralisation of dental enamel in the presence of fluoride. The procedure results in in situ transformation of the spherical ACP phase at the surface of the enamel to produce a contiguous overlayer of crystalline fluoridated hydroxyapatite, ca. 500 nm in thickness. We also show that similar methods can be developed for the effective occlusion of the porous array of channels present in dentine tubules when exposed to the ACP/PVP electrospun mats. Together, these studies suggest a new approach for the specific engineered regeneration of enamel and alleviation of dentine hypersensitivity and a general strategy for metastable mineralization of a range of substrates.