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Dynamic elastic modulus of 'packable' composites
Abe Y, Lambrechts P, Inoue S, Braem MJ, Takeuchi M, Vanherle G, Van Meerbeek B.
BIOMAT-Department of Operative Dentistry and Dental Materials, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, B-3000, Leuven, Belgium.
Dent Mater 2001 Nov;17(6):520-5
OBJECTIVE: A new type of so-called 'packable', 'condensable' or 'mouldable' composite
has been developed and aims at replacing amalgam for posterior restorations. The purpose of the present
investigation was to study the dynamic elastic modulus of 12 packable composites, and to follow the
evolution of this property following prolonged water absorption. METHODS: Of each material ten
rectangular samples (1.5x5x35 mm) were prepared. The elastic modulus (GPa) of each sample was
determined with a non-destructive dynamic method using a Grindo-Sonic after 24 h of dry storage at
room temperature, and after 24h, 1, 3 and 6 months of wet storage at 37 degrees C. All data were
analyzed using two-way ANOVA, Bonferroni/Dunn's test for multiple comparisons and paired t-test with
a significance level of p<0.05. In addition, inorganic filler volume percentages were derived from
the phenomenological model introduced by Braem et al. [11]. RESULTS: The studied materials varied widely
in terms of elastic modulus, ranging between composites classified as Compact-Filled Densified (elastic
modulus of 23.4+/-2.4 GPa) and as Microfine (elastic modulus of 8.5+/-2.1 GPa). SIGNIFICANCE: The great
diversity observed in the elastic modulus of this type of composites necessitates clear specifications
with regard to 'first' the definition of marketing terms such as packable and so on, and 'second' the
justified use in posterior teeth.
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