ABSTRACT
Especially for implanted materials that will withstand mechanical stresses in clinical use (e.g., in vascular or orthopedic applications), a proper mechanical characterization is among the most important physical tests that must be carried out. This will give the viability of applying the material in terms of its geometrical integrity, both at short term (determined by the elastic modulus and strength of the specimens) and long term (obtained from extrapolated creep/stress relaxation tests or fatigue). Before any specific mechanical test, one needs to specify clearly the functionality of the biomaterial, how it will work, the tissues with which it will be in contact, and the kind of mechanical environment that it will be facing. This will determine, for example, if it is most convenient to test the material in tension, compression, bending, shear, or in another more specific mechanical configuration. If the material swells easily in aqueous solutions, and if it is thermally sensitive near room temperature, one should test it while immersed in physiological simulated solutions and ideally at 37ºC. More complex tests are needed if one tries to simulate the mechanical environment of the implant; an example could be the evaluation of the implant-bone interface in orthopedic or dental applications, to evaluate the efficiency of coatings or cements as attachment tools.
