Study of physicochemical characteristics of calcium hydroxyapatite «Kalident Powder 100» in the development of dental medicine

Despite the development of the dental industry, the prevalence of dental hypersensitivity does not decrease but increases at a progressive rate. Given the above, the subject of our research was the development of dental medicinal films with micronized calcium hydroxyapatite under the trade name «Kalident Powder 100» (Kalichem, Italy) for the treatment of dental hyperesthesia and caries prevention. To establish the optimal method of calcium hydroxyapatite introduction into the dental film, it was necessary to study the influence of different dispersion mediums on the physicochemical characteristics of the substance under study. Purified water, ethyl alcohol 96%, polysorbate 80, glycerol, polyethylene oxide-400, propylene glycol, sunflower oil, vaseline oil were used as dispersion medium in the studies. Research of physico-chemical characteristics was performed both for the substance «Kalident Powder 100» separately and for its mixtures with the studied liquids and their combinations (in a ratio of 1:1). The following physico-chemical characteristics have been determined: disperse and diffraction analysis of particle size distribution, morphological description, linear dimensions, shape factor, volume coefficient, Martin and Ferret diameters, wettability. The results of crystallographic and disperse analysis have revealed the polydispersity of the substance «Kalident Powder 100» and its high ability to agglomerate, which may adversely affect the homogeneity of its distribution in the dental medicinal product. A study of the effect of different dispersion medium on the physicochemical characteristics of calcium hydroxyapatite has shown a positive effect of hydrophilic liquids on the wettability of powder particles, changes in their shape, size, and distribution in the studied samples. It has been established that the combination of the substance «Kalident Powder 100» with combined solvent systems containing purified water, polysorbate 80, glycerol, and PEO-400, allows achieving optimal shape and particle size of calcium hydroxyapatite with their uniform distribution throughout the liquid, which is also confirmed by the results of laser diffraction. The obtained results will be used in further research on the development of dental medicinal film.