Synthesis and solubility of calcium fluoride/hydroxy-fluorapatite nanocrystals for dental applications

Abstract As the mineral phase of tooth enamel consists of apatite containing fluoride, the “CaF2-like” salts are of significant interest in dentistry for their roles as labile fluoride reservoirs in caries prevention. Fluoride ion is required for normal dental development because of its therapeutic ability of osteoporosis healing and stimulating osteoblast activity both in vitro and in vivo. In this research, biphasic Calcium fluoride/fluorinated-hydroxyapatite (CF/FHAp) nanocrystals have been successfully synthesized via co-precipitation method. The synthesized powder was characterized by the commonly used bulk techniques such as chemical analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray powder diffraction (XRD) analyses. The obtained results confirmed the formation of biphasic powder composed of about 46% CF and 54% (w/w%) apatite phase which was a solid solution composed of more than 50% fluorapatite (FAp). In addition, in vitro evaluations of the powder were performed, and for investigating their bioactive capacity they were soaked in simulated body fluid (SBF) at different time intervals. The samples showed significant enhancement in bioactivity within few hours of immersion in SBF solution. Also, the EDS analysis clearly showed dissolution and deposition of calcium and phosphate ions on the surface of synthesized biphasic powder after the first week of immersion in SBF solution.