Modified method for synthesis of microwave-assisted irradiation hydroxyapatite for alveolar ridge preservation

Hydroxyapatite is one of the commonly used alloplastic material for alveolar bone regeneration. However, the currently practiced methods of synthesis are often time-consuming. The commercially available hydroxyapatite, even though were proven to attenuate alveolar bone resorption, they also showed a low biodegradability. This study is aimed to describe a new method of synthesising hydroxyapatite using microwave-assisted irradiation method. 52g Calcium nitrate tetrahydrate was dissolved in 5% hydrogen peroxide until it completely dissolved. Stoichiometric amount of 85% phosphoric acid were added dropwise, and the pH of the suspension was adjusted using ammonium hydroxide solution. The suspension was continuously stirred for additional 30 minutes at the room temperature. One part of the suspension was heated in household microwave at 800W for 10 minutes. Another half was filtered and washed using distilled water (named as filtration-HAp). Each suspension was further freeze-dried and calcined at 600C for 2 hours. The obtained powders were further characterised by using x-ray diffractometer, fourier transform infrared spectroscopy and energy dispersive x-ray fluorescence. Morphology of obtained powders were observed using field emission electron microscope. X-ray diffraction pattern of microwave-HAp showed high peaks indicating a highly crystalline structure. FTIR results confirms the presence of phosphate and hydroxyl groups. EDXRF showed calciumto-phosphorus ratio of 1.8. Microwave-HAP showed non-homogenous