Research results

Biological compatibility has been verified by cytotoxicity tests, according to ISO 10993, on samples extracted from manufactured sheets, in order to verify that processes do not compromise the initial compatibility of Titanium alloys. The samples were non-cytotoxic and this confirmed that the material is suitable for real implants (see figure below).

Finally, to verify the anatomical and surgical compatibility of the two prosthetic implants, they were assembled on synthetic skulls, expressly damaged, by four screws. Both prostheses have shown that the defect can be adequately filled and significant deviations between the outer surface of the prosthesis and the skull have not been observed. Furthermore, the aesthetic compatibility of the prostheses has been verified as well (see comparison in the following figure).

Functional compatibility of the prosthesis was verified through drop-tower impact tests. They had to be performed considering the same testing conditions and different heights of the falling object. Therefore a specific testing methodology has been developed. All tested configurations (up to the most critical condition which is characterized by a maximum energy of about 14 J, equal to a punctual impact of a mass of 2.295 kg falling from a height of 60 cm) did not cause either prosthesis breakage or collapse on the skull-screw anchoring system. This has demostrated superior mechanical properties of the manufactured prototypes.