caa a22 4500 475782518 CHVBK 20180406123648.0 cr unu---uuuuu 170329e20000701xx s 000 0 eng 10.1023/A:1008942223938 doi (NATIONALLICENCE)springer-10.1023/A:1008942223938 Mechanical properties of dental investment materials [Elektronische Daten] [D. low, M. Swain] Measurement of the elastic modulus (E) of investment materials has been difficult because of their low strength. However, these values are essential for engineering simulation and there are many methods available to assess the elasticity of materials. The present study compared two different methods with one of the methods being non-destructive in nature and can be used for specimens prepared for other tests. Two different types of investment materials were selected, gypsum-and phosphate-bonded. Method 1 is a traditional three-point bending test. Twelve rectangular bars with dimension of (70 x 9 x 3 mm) were prepared and placed on supports 56.8 mm apart. The test was conducted at a cross-head speed of 1 mm/min by use of a universal testing machine. The load applied to the test specimen and the corresponding deflection were measured until the specimen fractured. The E value was calculated from a linear part of the stress-strain plot. Method 2 is an ultra micro-indentation system to determine near surface properties of materials with nanometer resolution. The measurement procedure was programd such that the specimens were indented with an initial contact force of 5 mN then followed by a maximum force of 500 mN. Measurement consisted of 10 indentations conducted with a spherical stainless steel indenter (R = 250 μm) that were equally spaced (500 μm). The E value rose asymptotically with depth of penetration and would approach the three-point bending test value at approximately four time's maximum contact depth for both materials. Both methods are practical ways of measuring the E of investment materials. Kluwer Academic Publishers, 2000 low D. E-mail: dannylow@scientist.com aut Swain M. aut Journal of Materials Science: Materials in Medicine Kluwer Academic Publishers 11/7(2000-07-01), 399-405 0957-4530 11:7<399 2000 11 10856 https://doi.org/10.1023/A:1008942223938 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1008942223938 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- low D. E-mail: dannylow@scientist.com aut NATIONALLICENCE 700 1- Swain M. aut NATIONALLICENCE 773 0- Journal of Materials Science: Materials in Medicine Kluwer Academic Publishers 11/7(2000-07-01), 399-405 0957-4530 11:7<399 2000 11 10856 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer