Two-in-one strategy:a remineralizing and anti-adhesive coating against demineralized enamel

Tooth enamel is prone to be attacked by injurious factors,leading to a de/remineralization imbalance.To repair demineralized enamel and prevent pulp inflammation caused by biofilm accumulation,measures are needed to promote remineralization and inhibit bacterial adhesion on the tooth surface.An innovative material,poly(aspartic acid)-polyethylene glycol(PASP-PEG),was designed and synthesized to construct a mineralizing and anti-adhesive surface that could be applied to repair demineralized enamel.A cytotoxicity assay revealed the low cytotoxicity of synthesized PASP-PEG.Adsorption results demonstrated that PASPPEG possesses a high binding affinity to the hydroxyapatite(HA)/tooth surface.In vitro experiments and scanning electron microscopy(SEM)demonstrated a strong capacity of PASP-PEG to induce in situ remineralization and direct the oriented growth of apatite nanocrystals.Energy dispersive X-ray spectroscopy(EDS),X-ray diffraction analysis(XRD)and Vickers hardness tests demonstrated that minerals induced by PASP-PEG were consistent with healthy enamel in Ca/P ratio,crystal form and surface micro-hardness.Contact angle tests and bacterial adhesion experiments demonstrated that PASP-PEG yielded a strong antiadhesive effect.In summary,PASP-PEG could achieve dual effects for enamel repair and anti-adhesion of bacteria,thereby widening its application in enamel repair.