[The nature of metabolic processes in human dental hard tissues depending on their morphological structure]. / Kharakter obmennykh protsessov v tverdykh tkanyakh zubov cheloveka v zavisimosti ot ikh morfologicheskogo stroeniya.

THE STUDY OBJECTIVE: Was to give a comparative assessment of the movement of enamel and dentin fluid depending on the morphological structure of different sections of human dental hard tissues. MATERIALS AND METHODS: The research involved 140 female subjects aged 21-30 years. Sizes, form, surface of enamel-dentin junction, enamel prisms and their crystals in superficial, middle and deep sections, width, tortuosity, facing of dentin tubules of tested teeth were analyzed by scanning electron microscope Jeol JCM-5700 and atomic force microscope NTEGRA Prima. The biochemical study examined the quantitative content of water in the samples of enamel, dentin, enamel-dentin junction by weighing sample weights before and after drying. The data obtained were processed by methods of variation statistics using standard packages Microsoft Excel 2008, Statistica 12.0. RESULTS: The enamel-dentine junction of large-fastened type is characterized by zones of dentin integration into enamel at the distance of more than 10 mm, with regular arrangement of enamel prisms and wide dentine tubules of 3.55 to 4.70 µm in diameter; no water content reduction was found. The small-fastened type has less pronounced spots of dentin interference with enamel from 2 to 10 µm, the dentinal tubules are slightly curved with a diameter of 2.90 to 3.60 µm, the water content in dentin is reduced. In microfastened type, a linear structure with interpenetration zones up to 2 µm, enamel prisms slightly ordered, dentin tubules narrowed and curved in diameter from 1.30 to 1.95 µm, water content in enamel and dentin is reduced. CONCLUSION: At microfastened type of enamel-dentin junction, chaotic arrangement of enamel prisms and narrow dentin tubules water movement is broken and metabolic processes are reduced that determines high probability of exposure of dental hard tissue diseases.

[The impact of ureteral stent surface on encrustation and biofilm formation].

INTRODUCTION: Encrustation and biofilm formation is a clinical problem occurring with indwelling urinary drainage devices routinely used in urological practice. AIM: To investigate the impact of ureteral stent surface on encrustation and biofilm formation. MATERIALS AND METHODS: Polyurethane stents of two manufacturers were examined using the scanning electron microscopy and scanning probe microscopy before use and three weeks after their initial ureteral placement in patients with no evidence of a urinary tract infection and urolithiasis. RESULTS: In one case, there were irregularities in the form of pyramids with a height of 0.15+/-0.02 m with a tendency to occur at regular intervals, forming ordered rows, with a density of 2.67 per 10 m2. The cross-sectional area of the irregularities in the probe displacement direction was 1.015 m, after use - 1.271 m (25.2% increase). In another case, pyramids with a height of 0.39+/-0.03 m (p<0.0001) were detected without the pattern of repetition in the form of a network, the density was 3.31+/-10 m2. The cross-sectional area of the irregularities was 1.158 and 2.29 m2, respectively (an increase of 97.8%). In the first case, after three weeks of stent placement, the pyramids increased twofold, were amenable to counting, the biofilms had the appearance of scattered "loose" formations. In the second case, there were polygonal conglomerates of salts dozens of times larger than the primary elements; biofilms had the appearance of well-formed massive layers. CONCLUSION: The nature of the ureteral stent surface exerts a direct independent effect on the degree of encrustation and the formation of biofilms.