TENSILE AND TEAR PROPERTIES OF DENTAL DAM

The tensile and tear properties of highly extensible latex are sensiti ve to specimen shape, Three specimen shapes (ASTM D412 Die C dumbbell tensile specimen, rectangular tensile specimen with 1.74 mm hole, and ASTM D624 Die C tear specimen) were evaluated for proposed ANSI/ADA sp ecification #90 for dental dams, Fresh and aged dental darns from two manufacturers (Aseptico and Hygenic) in three weights (thin, medium, a nd heavy) and from two other manufacturers (Ivory and Ivoclar) in one weight (medium) were tested, Means and standard deviations of 10 speci mens for tensile strength (MPa), elongation (%), and tear strength (kN /m) are included herein, Data were analyzed by analysis of variance, M eans were compared by a Tukey-Kramer interval calculated at the 0.05 s ignificance level, The use of the dumbbell and tear specimens for the evaluation of dental dam should be reconsidered, The rectangular speci men with a hole is recommended for use in the proposed specification b ecause of its sensitivity to condition (fresh versus aged) and manufac turer.