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A modified technique to determine the tear energy of impression materials
Author(s) -
VRIJHOEF M. M. A.,
LOURENS F. L.,
LEYDEKKERSGOVERS G. F. M.
Publication year - 1986
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1111/j.1365-2842.1986.tb00666.x
Subject(s) - materials science , tear resistance , composite material , impression , mathematics , dentistry , medicine , computer science , world wide web , ultimate tensile strength
Summary A modified method to determine tear energy of impression materials is described. Trousers‐shaped specimens were prepared between two platens. They are different from those used before in that (1) a V‐shaped line is created so as to guide tear growth, and (2) the thickness gradually increases, then remains constant and, ultimately, decreases instantaneously. The specimens were tested at ten different rates between 0.2 and 50cm/min. λ can be computed from the force–time diagram. Six different materials were tested: two condensation silicones, Xantopren regular (Bayer, FRG) and Xantopren light; a polyvinylsiloxane, Reprosil regular (DeTrey, Switzerland); a polysulphide Coeflex regular (Coe, USA); a polyether, Impregum (Espe, FRG); and an alginate, Cavex, Fast Set, Dust Free (Keur & Sneltjes, The Netherlands). Tear strength (in kJ/m 2 ) variations at rates between 0.2 and 50cm/min are as follows: Xantopren regular, 0.37–0.64; Xantopren light, 0.29–0.46; Coeflex, 1.10–5–29; Reprosil, 0.66–1.07; Impregum, 0.62–1.04; Cavex, 0.22–0.37. These values are consistent with those reported before. It might be concluded that the new test method gives reliable tear energy values.