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Dynamic and static moduli of elasticity of resin-based materials
Sabbagh J, Vreven J, Leloup G.
Department of Conservative Dentistry, School of Dentistry, Universite catholique de Louvain, 15 Av Hippocrate, 1200, Brussels, Belgium
Dent Mater 2002 Jan;18(1):64-71
Objectives: The purpose of this study was to assess and compare the elastic moduli
of 34 resin-based materials using a dynamic and a static method. The effect of water storage was also
studied up to 6months.Methods: Five samples of each material were prepared according to ISO-4049.
The dynamic moduli were 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 900 degrees C.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 elasticity (r=0.94; p=0.0001) as well as between the 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 moduli of elasticity (ANOVA two factors; p<0.05).Significance: The low moduli of the
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.
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