Influence of fluoride additions on biological and mechanical properties of Na_2O–CaO–SiO_2–P_2O_5 glass–ceramics

摘要

Two series of Na_2O–CaO–SiO_2–P_2O_5 glass–ceramics dopedwith NH_4HF_2 (G-NH_4HF_2) or CaF_2 (G-CaF_2) have been prepared by sol–gelmethod. The glass–ceramic phase composition and morphologywere characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). Themechanical properties and thermal expansion coefficientweremeasured by a microhardness tester, an electronic tensile machine and a thermal expansion coefficient tester. The structure difference between these two glass–ceramics was investigated by Fourier transform infrared spectroscopy (FTIR), and the in vitro bioactivity of the glass–ceramics was determined by in vitro simulated body fluid (SBF) immersion test. The hemolysis test, in vitro cytotoxicity test, systemic toxicity test and the implanted experiment in animals were used to evaluate the biocompatibility of the glass–ceramics. The mechanical properties of sample G-NH_4HF_2 are lower than that of sample G-CaF_2, and the bioactivity of sample G-NH_4HF_2 is better than that of sample G-CaF_2. The thermal expansion coefficients of these two glass–ceramics are all closer to that of Ti6Al4V. After 7 days of SBF immersion, apatites were induced on glass–ceramic surface, indicating that the glass–ceramics have bioactivity. The hemolysis test, in vitro cytotoxicity test and systemic toxicity test demonstrate that the glass–ceramics do not cause hemolysis reaction, and have no toxicity to cell and living animal. The implanted experiment in animals shows that bone tissue can forma good osseointegrationwith the implant after implantation for twomonths, indicating that the glass–ceramics are safe to serve as implants.