Speaker
Description
Background: Additive manufacturing (AM) technologies such as Fused Filament Fabrication (FFF) and ARBURG Plastic Freeforming (APF) have become increasingly important in personalized medicine. To finally introduce AM to the clinic, preclinical investigations are necessary to guarantee patients’ safety. 3D-printed parts are expected to bear mechanical properties to serve as reliable bone replacements. PMMA (Polymethylmethacrylate) has already been used for years for medical applications and shows optimal characteristics in its milled form.
Material and Methods: Standard PMMA samples with dimensions of 80x10x4 mm were manufactured by FFF or APF to be evaluated for their mechanical characteristics by 3-point bending and charpy impact tests (ISO178 & 179). The printed samples were scanned in a µCT scanner (parameters: 80 kV potential, 500 µA current, 750 ms exposure time, 35.19 µm thickness). Segmentation, 3D modelling and volumetric analyses were done using 3D Slicer v4.10.2. A gap/hole in an image slice was defined as an island with a signal intensity below the threshold value without connection to the outer surface through neighbouring image sections.
Results: µCT analyses showed higher porosity of FFF specimens compared to ones manufactured with APF. Nevertheless, the levels of porosity observed in either of the groups (<0.5 %) did not seem to have a detectable impact on the strength and performance in the mechanical tests. Nevertheless, it should be noted that degrading or toxic ingredients used for cleaning and disinfection of the finished material might tend to be preserved in porous specimen for a longer time and may therefore reduce its biocompatibility.
Conclusion: Internal porosity was not at an extent to influence mechanical characteristics of AM PMMA samples. In a sister study, however, we observed that FFF specimens seem to release formaldehyde over a longer period compared to APF specimens due to a lower sample density.
| Speaker Country | Austria |
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