Journal of materials science-materials in medicine vol:4 issue:5 pages:471-480
The fatigue behaviour of a medical-grade thermoplastic polyolefin (TPO) was investigated with the objective of using TPOs for endoprosthetical aims in dental and orthopaedic applications. For this purpose, a TPO was subjected to the combined action of shear and compression fatigue while in contact with Hanks' solution. Cyclic loading between 150 and 1500 kPa shear stress and a number of cycles up to 9 x 10(6) was applied. The potential fatigue damage was assessed by in-fatigue-recording of the mechanical hysteresis curves and, after fatigue, by swelling tests in acetic acid solutions, dynamic mechanical thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The combined and critical application of these techniques allowed us to conclude that this material exhibits a very satisfactory fatigue behaviour under the loads investigated, making this material potentially useful for endoprostheses. Moreover, biomedical prescreening tests (according to USP Class VI) were all negative, stimulating continued research on this type of material.