Phosphoryl oligosaccharides of calcium enhance mineral availability and fluorapatite formation

ABSTRACT Objectives Phosphoryl oligosaccharides of calcium (POs-Ca) are a highly soluble calcium source and can keep the solubility of calcium and fluoride ions. The aim of this study was to investigate the effect of calcium (from POs-Ca) and fluoride ions penetrate into subsurface enamel lesions in vitro . Design Demineralized bovine enamel slabs were remineralized in vitro for 24 hours at 37 °C with artificial saliva (AS) containing POs-Ca and various fluoride concentrations (0-100 ppm), or AS containing different levels of POs-Ca adjusted to a Ca/P ratio of 0.4-3.0 and fluoride, then were analyzed using Transversal microradiography. From those results, remineralization effects with optimal conditions were compared between POs-Ca and calcium chloride (CaCl 2 ). To determine the form of incorporated fluoride, we analyzed the chemical state and local structure of fluorine atoms integrated into enamel subsurface lesions using micro X-ray absorption near-edge structure (μ-XANES) spectroscopy. Results A significant mineral recovery rate was observed with POs-Ca and fluoride at 0.5 or 1.0 ppm (n = 6, p  2 (15.0 ± 9.6 %) (n = 5, mean ± SD, p  Conclusions POs-Ca with fluoride-derived diffusion into subsurface enamel lesions facilitated formation of fluorapatite phases.