Applications of vibrational spectroscopy to biomaterials.

Some applications of vibrational spectroscopy to apatite-based biomaterials used in dental and bone tissues are here reported. In particular, titanium screws coated by Plasma Flame Spray with fluoroapatite were examined before and after implant in sheep femur for 10 weeks. Vibrational spectroscopy demonstrated that the powder used for the coating was a fluorinated hydroxyapatite (ca 40% of fluorination) containing impurities of calcium hydroxide and carbonate; in the coating the impurities disappeared and the crystallinity of the material decreased. Newly formed bone was present on the implanted screws, in close contact with the coating. The efficiency of carbonate substitution in carbonate hydroxyapatites synthesized by a hydrothermal method was evaluated. Vibrational spectroscopy permitted to evidence that the synthesized samples were constituted of B-type carbonato-apatite; the carbonation percentage was in the 1-12% range; the Raman I1072/I962 ratio and the full width at half-maximum of the 962 cm-1 band were good quantitative indexes of carbonate content.