[Study on the formation of fluorapatite with freeze-drying silicahydro gel method].

Resultant products and gel substance, formed with silicahydro gel method as well as with freeze-drying silicahydro gel method by use of tray, were compared and examined to materialize clinical application of gel method easily and the following results were obtained: 1. Evaluation of gel substance in control group gel (silicahydro gel) and in experimental group gel (gel prepared by the addition of deionized water to freeze-drying silicahydro gel) As the results of measuring the estimation of F- by ion chromatography and pH value, no clear-cut distinction between control group gel and experimental group gel was recognized, however, it was implied by naked-eye observations and through scanning electron microscope with the passage of time that experimental group gel had been inferior to control group gel. 2. Evaluation of resultant products in control group gel (resultant products formed with silicahydro gel method) and in experimental group gel (resultant products formed with freeze-drying silicahydro gel method) Naked-eye observations of reacting progress, the pH measurements, the calculation of Ca/P ratio, qualitative analyses by X-ray diffraction (reference; the measurements of crystallite size, lattice imperfection and lattice constant) and composition analyses by infrared absorption spectrum were carried out and as the results, resultant products in control group gel proved to be more favorable than those in experimental group gel. From the foregoing outcomes, it was suggested that fluorapatite of favorable crystallinity had been possible to be produced more with silicahydro gel method than with freeze-drying silicahydro gel method, and that further investigation inclusive of gel substance would be required in the event of clinically applying freeze-drying silicahydro gel method effectively.