5 research outputs found

    Nanohardness and young's modulus of tooth enamel

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    The nanomechanical properties and roughness of tooth enamel are investigated

    ΠœΠ•Π’ΠžΠ” Π­Π›Π•ΠšΠ’Π ΠžΠ₯Π˜ΠœΠ˜Π§Π•Π‘ΠšΠžΠ“Πž Π›Π˜Π—Π˜Π‘Π Π’ ΠžΠΠšΠžΠ›ΠžΠ“Π˜Π§Π•Π‘ΠšΠžΠ™ ΠŸΠ ΠΠšΠ’Π˜ΠšΠ• (ΠžΠ‘Π—ΠžΠ  Π›Π˜Π’Π•Π ΠΠ’Π£Π Π«)

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    Recently, minimally invasive treatment modalities based on the application of various physical factors have been widely used in anticancer therapy. Electrochemical lysis is a method in which tumor cells are destroyed by local exposure to a constant low voltage electric current.Purpose: to present the current results of using electrochemical lysis in the treatment of various tumors, to describe the mechanism of tumor destruction and methods of delivering electric current to the tumor, as well as to evaluate the electrical parameters and positioning of the electrodes.Material and Methods.aliterature search included the Medical literatureanalysis and Retrieval system Online (Medline), the excerpta Medica data Base (embase), Web of science, scopus, Russian citation index. All articles were published before december 2019. The review included studies on the investigation electrochemical lysis in vitro, in vivo, as well as clinical observations and clinical studies in which electrochemical lysis has been used as an independent treatment, or in combination with other methods of anticancer treatment since 1984.Results. This review provides information regarding the electrochemical mechanisms of tumor destruction, anti-tumoral effects of electrochemical therapy, methodology for planning and distributing the dose of electrical lysis and positioning of electrodes. We have evaluated complications and oncological results. Electrochemical lysis is a safe, simple, effective, and relatively non-invasive method of antitumor treatment.Conclusion. The electrochemical lysis is a promising minimally invasive method which can be used for the treatment of tumors. However, long-term data are needed to validate this treatment before it can be included into clinical recommendation for the treatment of cancer patients.Π’ онкологичСской ΠΏΡ€Π°ΠΊΡ‚ΠΈΠΊΠ΅ всС Π±ΠΎΠ»Π΅Π΅ вострСбованными становятся ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹ ΠΌΠ°Π»ΠΎΠΈΠ½Π²Π°Π·ΠΈΠ²Π½ΠΎΠ³ΠΎ лСчСния, основанныС Π½Π° ΠΏΡ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠΈ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… физичСских Ρ„Π°ΠΊΡ‚ΠΎΡ€ΠΎΠ², ΠΊ ΠΊΠΎΡ‚ΠΎΡ€Ρ‹ΠΌ, Π² Ρ‚ΠΎΠΌ числС, относят элСктрохимичСский лизис, Π²Ρ‹Π·Ρ‹Π²Π°ΡŽΡ‰ΠΈΠΉ Ρ€Π°Π·Ρ€ΡƒΡˆΠ΅Π½ΠΈΠ΅ ΠΎΠΏΡƒΡ…ΠΎΠ»Π΅Π²Ρ‹Ρ… ΠΊΠ»Π΅Ρ‚ΠΎΠΊ Π² Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Π΅ мСстного воздСйствия постоянным элСктричСским Ρ‚ΠΎΠΊΠΎΠΌ Π½ΠΈΠ·ΠΊΠΎΠ³ΠΎ напряТСния.ЦСль исслСдования – ΠΏΡ€Π΅Π΄ΡΡ‚Π°Π²ΠΈΡ‚ΡŒ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ примСнСния ΠΌΠ΅Ρ‚ΠΎΠ΄Π° элСктрохимичСского лизиса Π² Ρ‚Π΅Ρ€Π°ΠΏΠΈΠΈ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… Π½ΠΎΠ²ΠΎΠΎΠ±Ρ€Π°Π·ΠΎΠ²Π°Π½ΠΈΠΉ, свСдСния ΠΎ ΠΌΠ΅Ρ…Π°Π½ΠΈΠ·ΠΌΠ΅ ΠΏΡ€ΠΎΡ‚ΠΈΠ²ΠΎΠΎΠΏΡƒΡ…ΠΎΠ»Π΅Π²ΠΎΠ³ΠΎ дСйствия, способах доставки элСктричСского Ρ‚ΠΎΠΊΠ° ΠΊ ΠΎΠΏΡƒΡ…ΠΎΠ»ΠΈ, ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€Π°Ρ… воздСйствия ΠΈ позиционирования элСктродов.ΠœΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π» ΠΈ ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹. Поиск ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈ Π² Π±Π°Π·Π°Ρ… Π΄Π°Π½Π½Ρ‹Ρ… Medline, eMBase, Web of science, scopus, Π ΠΈΠ½Π¦, ΠΎΠΏΡƒΠ±Π»ΠΈΠΊΠΎΠ²Π°Π½Π½Ρ‹Ρ… Π΄ΠΎ дСкабря 2019 Π³. Π’ ΠΎΠ±Π·ΠΎΡ€ Π²ΠΊΠ»ΡŽΡ‡Π°Π»ΠΈ Ρ€Π°Π±ΠΎΡ‚Ρ‹, посвящСнныС ΠΏΡ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡŽ элСктрохимичСского лизиса in vitro, in vivo, Π° Ρ‚Π°ΠΊΠΆΠ΅ клиничСскиС наблюдСния ΠΈ исслСдования, Π² ΠΊΠΎΡ‚ΠΎΡ€Ρ‹Ρ… ΠΌΠ΅Ρ‚ΠΎΠ΄ Π±Ρ‹Π» использован ΠΊΠ°ΠΊ Π² качСствС ΡΠ°ΠΌΠΎΡΡ‚ΠΎΡΡ‚Π΅Π»ΡŒΠ½ΠΎΠΉ Ρ‚Π΅Ρ€Π°ΠΏΠΈΠΈ, Ρ‚Π°ΠΊ ΠΈ Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°Ρ†ΠΈΠΈ с Π΄Ρ€ΡƒΠ³ΠΈΠΌΠΈ ΠΌΠ΅Ρ‚ΠΎΠ΄Π°ΠΌΠΈ лСчСния с ΠΌΠΎΠΌΠ΅Π½Ρ‚Π° появлСния ΠΏΠ΅Ρ€Π²ΠΎΠΉ ΠΏΡƒΠ±Π»ΠΈΠΊΠ°Ρ†ΠΈΠΈ Π² 1984 Π³.Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹. ΠŸΡ€Π΅Π΄ΡΡ‚Π°Π²Π»Π΅Π½Ρ‹ соврСмСнныС знания ΠΎ ΠΌΠ΅Ρ…Π°Π½ΠΈΠ·ΠΌΠ°Ρ… ΠΏΠΎΠ²Ρ€Π΅ΠΆΠ΄Π°ΡŽΡ‰Π΅Π³ΠΎ дСйствия элСктрохимичСского лизиса, ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠ»ΠΎΠ³ΠΈΠΈ планирования ΠΈ распрСдСлСния Π΄ΠΎΠ·Ρ‹ элСктровоздСйствия ΠΈ позиционирования элСктродов. Π’ клиничСских исслСдованиях ΠΎΡ†Π΅Π½Π΅Π½Ρ‹ ослоТнСния ΠΈ онкологичСскиС Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹. Анализ Π»ΠΈΡ‚Π΅Ρ€Π°Ρ‚ΡƒΡ€Ρ‹ ΠΏΠΎΠΊΠ°Π·Π°Π», Ρ‡Ρ‚ΠΎ ΠΌΠ΅Ρ‚ΠΎΠ΄ элСктрохимичСского лизиса являСтся бСзопасным, эффСктивным ΠΈ ΠΎΡ‚Π½ΠΎΡΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎ Π½Π΅ΠΈΠ½Π²Π°Π·ΠΈΠ²Π½Ρ‹ΠΌ ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ ΠΏΡ€ΠΎΡ‚ΠΈΠ²ΠΎΠΎΠΏΡƒΡ…ΠΎΠ»Π΅Π²ΠΎΠ³ΠΎ лСчСния Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… Π½ΠΎΠ²ΠΎΠΎΠ±Ρ€Π°Π·ΠΎΠ²Π°Π½ΠΈΠΉ с ΠΎΠ±Π½Π°Π΄Π΅ΠΆΠΈΠ²Π°ΡŽΡ‰ΠΈΠΌΠΈ краткосрочными онкологичСскими ΠΈ Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΎΠ½Π°Π»ΡŒΠ½Ρ‹ΠΌΠΈ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Π°Ρ‚Π°ΠΌΠΈ.Π—Π°ΠΊΠ»ΡŽΡ‡Π΅Π½ΠΈΠ΅. ΠœΠ΅Ρ‚ΠΎΠ΄ элСктрохимичСского лизиса являСтся пСрспСктивным Π²Π°Ρ€ΠΈΠ°Π½Ρ‚ΠΎΠΌ ΠΌΠ°Π»ΠΎΠΈΠ½Π²Π°Π·ΠΈΠ²Π½ΠΎΠ³ΠΎ лСчСния, ΠΊΠΎΡ‚ΠΎΡ€Ρ‹ΠΉ ΠΌΠΎΠΆΠ΅Ρ‚ Π±Ρ‹Ρ‚ΡŒ использован ΠΏΡ€ΠΈ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… новообразованиях. Однако отсутствиС проспСктивных клиничСских исслСдований с Ρ…ΠΎΡ€ΠΎΡˆΠ΅ΠΉ Π΄ΠΎΠΊΠ°Π·Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ Π±Π°Π·ΠΎΠΉ ΠΏΠΎΠΊΠ° Π½Π΅ позволяСт Π²ΠΊΠ»ΡŽΡ‡ΠΈΡ‚ΡŒ Π΅Π³ΠΎ Π² Ρ€Π΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°Ρ†ΠΈΠΈ ΠΏΠΎ Π»Π΅Ρ‡Π΅Π½ΠΈΡŽ злокачСствСнных ΠΎΠΏΡƒΡ…ΠΎΠ»Π΅ΠΉ ΠΈ ΠΏΡ€ΠΈΠΌΠ΅Π½ΡΡ‚ΡŒ Π² ΡˆΠΈΡ€ΠΎΠΊΠΎΠΉ клиничСской ΠΏΡ€Π°ΠΊΡ‚ΠΈΠΊΠ΅

    The Poisson’s Ratio of enamel, dentin and dental restoration materials

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    The Poisson ratio and the Young’s modulus form a pair of independent material constants of solids. For hard tooth tissues the Poisson’s ratio should correspond to the Poisson’s ratio of restorative materials in order to avoid overstresses at the border of the sections, restoration material-enamel and restoration material-dentin on microscopic level. In this paper on base orientation dependencies the extremal (minimum and maximum) Poisson’s coefficients of dentin and enamel are calculated. In the analysis, dentin and enamel was considered as an anisotropic medium with hexagonal symmetry with a known matrix of elastic constants. It is established that the interval of possible values of the Poisson’s ratio of dentin and enamel is much wider than the range of changes in the Poisson’s ratio of known dental composite materials, which in some cases can reduce the quality of restorations in microvolumes. It is shown that the maximum value of the Poisson’s ratio of dentin (0.534) is greater than the upper theoretic limit for the Poisson’s ratio of isotropic materials

    Influence of sugar and sweet foods on the hardness of tooth enamel

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    Human nutrition has changed dramatically over the past few decades. The food industry now offers a huge variety of attractive foods that are high in sugars and acids, and the average human consumption of these soft drinks, snacks and convenience foods has skyrocketed. It has been established that nutrition significantly affects dental health. For example, excessive consumption of sugar and sugar-containing foods significantly increases the development of tooth decay. On the other hand, it has been proven that the mechanical properties of the hardness and elastic modulus of enamel and dentin are a predictor of tissue erosion and cariogenic changes in the structure of teeth and can be considered as diagnostic indicators. In this regard, it seems interesting and timely to review the literature data on the study of the effect of sugar and sweet foods on the hardness of tooth enamel
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