Synthesis of nanocrystalline fluorinated hydroxyapatite by microwave processing and its in vitro dissolution study

Abstract

Synthetic hydroxyapatite, (Ca 10 (PO 4 ) 6 (OH) 2 , HA), is an important material used for orthopedic and dental implant applications. The biological hydroxyapatite in the human bone and tooth is of nanosize and differs in composition from the stoichiometric HA by the presence of other ions such as carbonate, magnesium, fluoride, etc. Osseointegration is enhanced by using nanocrystalline HA. This stimulates the interest in synthesizing nanocrystalline HA by different routes and among the methods, microwave processing seems to form the fine grain size and uniform characteristic nanocrystalline materials. Fluorinated hydroxyapatite, (FHA, Ca 10 (PO 4 ) 6 (OH) 2-x F x ), possesses higher corrosion resistance in biofluids than pure HA and reduces the risk of dental caries. The present work deals with the synthesis of nanocrystalline FHAs by microwave processing. The crystal size and morphology of the nanopowders were examined by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) methods. The functional groups present in FHA powders were ascertained by Fourier transform infrared spectroscopy (FT-IR) and laser Raman spectroscopy. Since the physiological stability is an important parameter while selecting the material for implantation, the in vitro dissolution studies of FHAs with different fluorine contents were carried out.

Preparation of laminated poly(ε-caprolactone)-gelatin-hydroxyapatite nanocomposite scaffold bioengineered via compound techniques for bone substitution

“…Among these bands, two bonds were observed at 3,555 and 622 cm −1 due to the stretching mode of hydrogen-bonded OH - ions and the liberational mode of hydrogen-bonded OH - ions, respectively. In addition, the band at 1,040 cm −1 arises from ν 3 PO 4 , and the bonds at 605 and 560 cm −1 arise from ν 4 PO 4 50 . The FTIR analysis showed all typical absorption characteristics of the HAp powder, and, according to these explanations, it is obvious that the synthesized powder is certainly HAp.…”

Hydroxyapatite and a New Fibrin Sealant Derived from Snake Venom as Scaffold to Treatment of Cranial Defects in Rats

“…The synthesis of HA resulted in the formation of calcium phosphate whose FTIR and X-ray diffraction spectra proved to be similar to HA 30,31 . The crystal size of synthetized HA was similar to that found for cortical bone being about 50 nm 34 .…”

X-Ray Peak Profile Analysis of Nanostructured Hydroxyapatite and Fluorapatite

“…The precursors used and the detailed procedure for the synthesis of HA [9] and FA [10] particles was reported in one of the authors previous study.…”

“…The calculated percentage crystallinity of HA and FA are 22 and 50. The improved crystallinity of FA may come from the driving force provided by the high affinity F -groups (compared to OH -groups in the precursor solution) for the apatite crystal growth during precipitation [10].…”