Effects of bovine milk osteopontin on in vitro enamel remineralization as a topical application prior to immersion in remineralizing solutions with/without fluoride

Remineralization effects of enamel binding peptide, WGNYAYK, on enamel subsurface demineralization in vitro. Enamel binding peptide, WGNYAYK effect remineralization of enamel

Objectives: We investigated remineralization effects of enamel binding peptide (EBP), WGNYAYK, on enamel subsurface demineralization in vitro.Methods: Bovine lower incisor crowns were used as subsurface enamel demineralization samples, and changes of EBP binding, remineraliztion rate, hardness and microstructure were investigated. Binding of EBP, remineralization rate, hardness and structural changes were investigated. Fluorescein isothiocyatate (FITC)-labeled EBPs (0.4 mM, 4.0 mM, and 7.0 mM) were applied to the samples for 30 min at 37 °C, with sample surfaces and cross-sections observed by confocal laser scanning microscope (CLSM). Mineralization analysis samples were divided into 4 experimental groups; distilled water (DW), EBP 0.4 mM, EBP 4.0 mM, and EBP 7.0 mM. Mineral density changes were measured by micro-CT with hardness measured by nano-indentation. Samples were also observed by scanning electron microscope (SEM) for surface and longitudinal microstructure.

Results

CLSM images indicated that increased fluorescence was observed in the surface layer and up to about 20 μm below the surface layer. The remineralization rate was significantly higher for EBP 7.0 mM compared to DW (p = 0.008). Enamel surface hardness was significantly higher in all EBP groups compared to DW (p < 0.05) and was highest in the 7.0 mM group. SEM images showed obscuring of the superficial columnar structure in the 7.0 mM EBP group, indicating subsurface crystalline structure recovery.

Conclusion

The results of this study suggest that EBP binds to demineralized enamel and promotes remineralization.