In Ukrainian

Abstract

The aim of the research is the development of compositions and technology for obtaining bioactive glass-ceramic calcium phosphate-silicate coatings on titanium for dental prosthetics, to find the relationship between the structural parameters of the calcium phosphate-silicate coatings surface on titanium with their bioactivity. The structure of the material was studied by means of petrographic analysis (microscope Mi-2e) and X-ray phase analysis (DRON-3M). Solubility and bioactivity of coatings were evaluated in solutions: distilled water (GOST R 31576-2012), SBF (ISO 23317:2012), 10 % albumin solution. The surface free energy was determined by the Owens-Wendet-Rebel-Kaebel method. The surface microrelief of the coatings was assessed by the mean arithmetic deviation of the profile Ra (Surtronic 3+ profilometer). The surface layer structure was investigated by X-ray fluorescence (SPRUT spectrometer-analyzer) and X-ray spectral (PEM Tesla 3 LMU + oxygen spectrometer Oxford X-max 80 mm) methods. The behavior of stem cells on the coatings surface was investigated by fluorescence microscopy (Carl Zeiss Axio Observer Z1). Criteria were selected of model glass synthesis and the model glasses were melted. Glass-ceramic coatings for titanium were applied by slip technology and synthesized under conditions of short-term low-temperature heat treatment. It has been found that the model glasses, after heat treatment, are characterized by behaviour of a volumetric fine-disperced (crystals ≤ 1 μm) crystallization of calcium phosphate - HAP and FAP (Σ ≈ 24÷44 % by volume). The possibility of spontaneous adsorption of proteins on the coatings surface has been confirmed due to the provision of coating parameters: SEM ≈ 65 mJ/m 2 , R a ≈ 3.5 μm and the presence of through pores with a diameter of 10÷100 μm. The changes in the structure and composition of the coatings surface after ageing in SBF have been studied for 1 month period. It has been found that the provision for these model glasses of a set of indicators, namely: solubility in distilled water (30 days) - 0.89 wt. %; ion yield of Ca 2+ is 0.26 wt. % and groups [PO 4 ] 3 – -0.162 wt. %, pH ~ 7.3, is sufficient for the formation of precursors of hydroxyapatite on the coatings surface in vitro. Gradual displacement (build-up) of the coatings surface layers (due to the dissolution of the coating and deposition of the SBF components) was found within the boundaries up to 6.7 μm and the apatite-like layer was formed in 28 days of soaking. These structural and chemical transformations of the surface of glass-ceramic coating form a durable apatite-like layer for 35 days period under in vitro conditions. The formation of this layer creates conditions for increasing the area of mesenchymal stem cell spacing on the coatings surface and allows their use in the creation of bioengineering design with stem cells (in vivo).