Tinius Olsen offers solutions for testing medical devices including tensile strength, impact strength, flexural, puncture, shear, friction and more.
Tinius Olsen’s versatile benchtop testing machines can perform many materials test routines that meet ASTM, ISO and other international specifications, including tensile, compressive, tear, peel, flexural, puncture, shear and frictional resistance tests.
To measure the force produced by a wire as it returns to its original shape after it has been deflected, in other words, the force experienced by teeth as they are moved by a wire, a 3-point bending test was conducted by an examiner (R.C.P.-R.) using the Tinius Olsen 1kN testing machine. The test was performed in accordance with ISO 15841 standard. The machine has 2 stainless steel fulcrums 10 mm apart between their respective centers to serve as supporting points for the wire specimen. The entire apparatus was housed in a closed chamber maintained at 37°C to simulate average oral temperature.
All wires were sectioned into 20-mm-long specimens, rested across the 2 supporting points, and left in the temperature-stabilized testing chamber for 3 minutes, allowing the wire to reach the chamber temperature. Then each specimen was deflected from 0 to 3.1 mm and back to 0 mm with a stainless steel pointed bar measuring 0.1 mm at its head, traveling at a speed of 10.0 mm per minute. A computer attached to the testing machine recorded 1000 data points for the force placed on and delivered by the wire through the entire loading and unloading process. Rectangular wires were measured under vertical loads that were applied on their long sides, mimicking the forces that teeth would experience when being leveled occlusogingivally. To eliminate variability from cyclic loading, measurements were taken only on specimens that had never been tested or deflected before. To compare forces upon unloading, values recorded at 2 mm of deflection were used for all statistical analyses.