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BIO MATERIALS - Click here to return to overview or click on a title to download the document
- Comparison of the Young's modulus for six reinforced dental materials
Authors: Brett I. Cohen, Mark Pagnillo, Barry Lee Musikant, Allan S. Deutsch, Gary Cofrancesco
Language: English
This in vitro study concerns the modulus of elasticity, Young's modulus, and compares physical characteristics for six reinforced dental materials. Young's modulus is the measurement of stress per strain that the material can withstand before catastrophic failure. In a through study by Braem et al. over 40 posterior composites were tested and the Young's modulus was measured using a non-destructive technique. Feilzer et al. in a similar study tested four posterior composites. In these studies no measurements were performed for core materials or cementation agents.
- Determination of Young's modulus of dental composites : a phemenological model,
Authors: M. Braem, V.E. Van Doren, P. Lambrechts, G. Vanherle
Language: English
The Young's Moduli of isotropic dental restorative composites are determined with a non-destructive dynamic method, which is based on the measurement of the duration of the fundamental period for the first harmonic of a freely oscillating sample. Statistical analysis of these results yields a phenomenological model in which Young's modulus is given by an exponential rule of mixtures of the matrix phase and the filler phase of the composites. It is found that this phenemenological rule is substantiated empirically.
- Dynamic and static moduli of elasticity of resin-based materials
Authors: J. Sabbagh, J. Vreven, G. Leloup, Dental materials 18 (2002) 64-71
Language: English
Objectives: The purpose of this study was to assess and compare the elastic moduli of 34 resin-based materials using a dynamic and static method. The effect of water storage was also studied up to 6 months. Methods: Five samples of each material were prepared according to ISO-4049. The dynamic moduli we first determined non-destructively from the fundamental period of the vibrating specimen, then the static moduli were determined by a three-point bending test. The percentages of fillers by weight were determined by ashing in air at 900ºC. Results: Low values were obtained with flowable composites as well as with two packable resin composites. Correlations were found between the static and the dynamic modulus of eslasticity (r=0.94; p=0.0001) as well as between weight percentage of fillers and the moduli of elasticity (r=0.82; p<0.05 for static modulus and r=0.90; p<0.05 for the dynamic modulus) both at 24h. Water storage significantly affected both static and dynamic modulus of elasticity (ANOVA two factors; p<0.05). Significance: The low moduli of flowable composites do not allow their use in posterior cavities under high stress. However, this does not exclude their use for minimally invasive Class I cavities when the opposing tooth is stabilized to a large amount on the natural enamel. The Grindosonic method is very useful and simple for determining the dynamic moduli although it gives higher values than the static one. The elastic modulus evolution of resin-based materials after water storage is unpredictable since different patterns were observed as a function of time.
- On the measurement of the elastic modulus of a vitreous coating on a titanium substrate by the resonance method
Authors: P. Van Landuyt, J.M. Streydio, F. Delannay, E. Munting, Université Catholique de Louvain
Language: English
We have synthesized a biocompatible glass that, when used as a glaze, allows wetting and adhesion on a titanium substrate. The elastic modulus of this glaze cannot be measured isolately. It is possible to calculate the modulus of the vitreous coating by measuring the resonant frequencies of a titanium plate before and after the deposition of the glaze. The values obtained can be compared to the modulus of elasticity of bulk glass. The evolution and the dispersion of the calculated modulus values are followed in function of the density for three different coatings.
- Revêtements vitreux sur titane pour application aux prothèses articulaires,
Authors: P. Van Landuyt, UCL, Faculté des Sciences Appliquées, Unité de Physico-Chimie et Ingénierie des Matériaux
Language: French
Le module d'élasticité d'un revêtement est une propriété importante car elle est indispensable à la compréhension du comportement du revêtement lorsqu'il est soumis à des contraintes. Notamment, le module d'élasticité est une donnée de base lors du calcul des contraintes résiduelles dans le revêtement.
- The impact of composite structure on its elastic response,
Authors: M. Braem, P. Lambrechts, V. Van Doren and G. Vanherle
Language: English
The non-destructive determination of Young's modulus of dental composites by measn of the fundamental period was found to be reliable and accurate. Post-polymerization effects could clearly be detected. Exponential regression analysis showed a correlation coefficient of 0.92, after logarithmic transformation, with volumetric filler content. The high accuracy and reliability of the measurments themselves are reflected in low standard deviations. The results are in excellent agreement with those of other investigations. Furthermore, the ease and speed of operation make this new procedure a powerful laboratory tool for material-testing and practical large-scale investigations.
- The relationship between test methodology and elastic behavior of composites
Authors: M. Braem, C.L. Davidson, G. Vanherle, V. Van Doren and P. Lambrechts
Language: English
Comparisons were made of the Young's moduli obtained with tests that impose static, low-frequency, or high-frequency elastic deformations on dental composite systems. The frequency of the imposed stress was reflected in the absolute value of Young's modulus. However, the values obtained at different test frequencies could be compared and understood by taking into account this frequency dependence. It was thus found that the composite structure largely determined the type of reaction to the imposed stress. The fundamental period test permitted the greatest differentiation in the classic behavior of the investigated composites.
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