title: [Studies on the influence of mixing ratio and manual or mechanical mixinng ratio and manual or mechanical mixing on physical properties of composites (author's transl)].
abstract: The study was carried out in order to see whether the physical properties (microhardness, cone-flow-point, compressive strength, abrasion resistance, density, dimensional change adherence to enamel) of the powder-liquid- composite are dependent upon the processing conditions (powder-liquid-ratio, manual or mechanical mixing). We found that the higher the powder-liquid-ratio the higher the microhardness, compressive strength, density and the least the volume contraction. The abrasion resistance and the adherence to enamel depended not significantly upon the mixing ratio. In a manual mixed composite the highest cone-flow-point has been found to lie between a high and a low powder-liquid-ratio. All this findings show clearly that a standardized powder-liquid-ratio is a necessary prerequisite to an optimal quality of the composite. This optimal ratio can be guaranteed by a proper predosage in capsules. Mechanical mixing increased the microhardness, cone-flow-point, compressive strength and density. This fact is due to homogenity and small porosity. Mechanical mixed and injection-capsule composites are recommendable.
mesh_terms: D001696:Biomechanical Phenomena; D003188:Composite Resins / Q000032:analysis*; D006244:Hardness; D006801:Humans; D013718:Tensile Strength
chemical_list: D003188:Composite Resins
vernacular_title: Untersuchungen über den Einfluss von Mischungsverhältnis sowie manuellem und maschinellem Mischen auf physikalische Eigenschaften von Komposits.