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Enamel Thickness Differs between Field and Forest European Roe Deer Capreolus capreolus

Demesko Jan, Kurek Marta, Podlaszczuk Patrycja, Markowski Janusz

Polish Journal of Ecology

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2020

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Vol. 68, nr 1

100--107

EN

Dental enamel is the hardest tissue of the mammalian body, consisting of 96-98% inorganic compound. As the dentition is functionally adapted to diet and feeding behaviour, relative differences in enamel thickness can reflect dietary adaptations. We hypothesize that differences in enamel thickness are related to adaptation for diet associated with habitat quality dwelling of European roe deer Capreolus capreolus. To test this hypothesis, 49 first permanent left lower molars were extracted from the mandible of roe deer (from Lithuania – 28 and Poland – 21 molars) inhabiting two type of habitats: field and forest. The linear thickness of total enamel (mean value of enamel thickness measured at three different points) was found to differ between the roe deer from the field and forest habitats, irrespective of age, with the animals of field ecotype tend to have thinner enamel (F(1,26) = 6.845, P = 0.025). This suggests that there is an adaptation in enamel thickness to various types of diet in the field and forest habitat. On the other hand, roe deer from the field habitat can be also more exposed to stress, due to the lower possibility to hide or are more vulnerable to potential threats. More frequent exposure to stress can significantly disrupt ameloblasts secretion and thus affect the thickness of the enamel.

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Tribological characteristics of enamel–dental material contacts investigated in vitro

Wojda S., Szoka B., Sajewicz E.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 1

21--29

EN

Purpose: The aim of this study was to investigate wear and friction behaviour of tooth enamel against selected dental restorative materials. Methods: The experimental material was obtained under simulated mastication, during which human tooth enamel was subjected to friction and wear in contact with composite dental materials: Estelite Sigma and FulFil Extra. Results: The results have shown that the enamel’s resistance to tribological wear is significantly higher than the resistance of the dental materials tested. The microscopic observations of the sample surfaces subsequent to the tribological research as well as the analysis of the chemical composition of the surface layer confirm the existence of diverse tribological wear mechanisms dependent on the type of dental materials used. Conclusions: Composite materials such as Estellite Sigma and FulFil Extra are characterized by greater resistance to wear and are less destructive to enamel than the material investigated by the authors earlier. It has also been stated that the spherical shape of the filler particles (Estellite Sigma) has a beneficial effect in reducing enamel wear.

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Comparative analysis of two methods of assessment wear of dental materials

Wojda S.

Acta Mechanica et Automatica

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2015

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Vol. 9, no. 2

105--109

EN

Wear of dental materials used for permanent dental fillings has a significant impact on their lifetime. Wear products generated during chewing process involving direct tribological contact between a composite and tooth enamel can cause damage not only to enamel itself but also to the entire tooth structure thus affecting the patient’s the health. It is essential therefore to assess the process of wear rates as well as the usefulness and effectiveness of the method used to measure these values. As there are a number of different methods used to quantify the loss of dental materials subjected to friction, eg.: scanning digital 3D models of dental casts, confocal microscope scanning or profilographometer measurements, the authors chose to analyze two selected research methods using confocal microscopy and profilographometer to assess their effectiveness. Two commercially available composite dental materials, i.e. ES and FFE previously subjected to friction tests in contact with human dental enamel, were used for the analysis.

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Analiza uwarunkowań decydujących o odporności szkliwa na zużycie. Część 2, Badania warstwy wierzchniej oraz mikrotwardości szkliwa zębowego

Ryniewicz W., Herman M., Ryniewicz A. M.

Engineering of Biomaterials

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2011

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Vol. 14, no. 102

23--27

PL

Opracowanie stanowi kontynuację zagadnień, w których wskazano uwarunkowania decydujące o odporności szkliwa naturalnego na zużycie. W części II opisano badania obejmujące ocenę stereometrii warstwy wierzchniej szkliwa z wykorzystaniem mikroskopii sił atomowych (AFM) oraz wyznaczenie mikrotwardości zębów z wykorzystaniem metody Oliver&Pharr. Analizę statystyczną parametrów morfologicznych szkliwa z zębów przedtrzonowych i trzonowych prze-prowadzono z zastosowaniem programu Scanning Probe Image Processor. Analiza pozwoliła identyfikować obrazy o różnym zakresie skanowania, wyznaczyć parametry chropowatości powierzchni na poziomie nano oraz różnicować struktury w sposób jakościowy i ilościowy. Zmiany chropowatości miały charakter okresowy o zbliżonych parametrach amplitudy, a częstotliwość była stała lub była wielokrotnością parzystą. Badania parametrów mikromechanicznych, poprzez nanoindentację, pozwoliły wyznaczyć twardość szkliwa oraz moduł sprężystości (Younga) na powierzchniach koron zębów trzonowych dolnych. Na podstawie charakterystyk wytrzymałościowych i pomiarów ustalono, że twardość zawarta była w przedziale od 337,2 HV do 335,3 HV, a moduł sprężystości w przedziale od 95,8 GPa do 106,3 GPa. Stwierdzono daleko posuniętą regularność w strukturach warstwy wierzchniej szkliwa oraz dużą powtarzalność w badaniach mikromechanicznych.

EN

This paper is a continuation of the issues that has pointed determinants deciding about the resistance of natural enamel to wear. Part II contains the examinations including the assessment of enamel superficial layer stereometry using Atomic Force Microscopy (AFM) and determination of teeth microhardness using Oliver & Pharr method. Statistical analysis of morphologic parameters in enamel from premolar and molar teeth was made using Scanning Probe Image Processor software. The analysis allowed the identification of images with various range of scanning, determination of roughness parameters of the surface in nanoscale and quantitative and qualitative differentiation of the structures. Changes in roughness are periodic, with similar parameters of amplitude, and a frequency can be constant or is an even multiple. Determination of enamel hardness and Young’s modulus for the surface of dental crowns in lower molar teeth were possible by micromechanical study using nanoindentation. Based on performance characteristics and measurements it was established, that the hardness ranged from 337.2 HV to 335.3 HV, and Young’s modulus ranged from 95.8 GPa to 106.3 GPa. Highly regular pattern in structures of enamel superficial layer and high repeatability in micromechanical examinations were found.

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Numeryczne wspomaganie impulsowych badań dyfuzyjności cieplnej niejednorodnych preparatów tkankowych

Sypek J., Żmuda S., Panas A.

Biuletyn Wojskowej Akademii Technicznej

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2003

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Vol. 52, nr 10

54-71

PL

Przedstawiono przykład zastosowania numerycznych technik obliczeniowych, bazujących na metodzie elementów skończonych do analizy badań dyfuzyjności cieplnej niejednorodnych preparatów tkankowych. Dla numerycznych modeli uproszczonych 1-D, 2-D i 3-D wykonano obliczenia, w oparciu o które określono wymagania dotyczące budowy modelu numerycznego, metodykę pomiarów, wielkości błędów. Omówiono problemy wynikające ze stosowania w badaniach pakietu inżynierskiego Cosmos. Zaprezentowano budowę modelu numerycznego, będącego odwzorowaniem rzeczywistego preparatu zęba. Przedstawiono porównanie uzyskanych wyników z danymi literaturowymi.

EN

The example is presented of using the finite element numerical method for analysis of thermal diffusivity of non homogeneous tissue samples. For simplified 1-D, 2-D and 3-D models the calculations have been carried out, on the basis of which the requirements concerning the architecture of the numerical model, measurement method and the error value have been established. The problems appearing during the use of the engineering Cosmos file have been discussed. The numerical model structure reflecting the real tooth is presented. The comparison of the obtained results with the literature data are also presented.