The resulting 3D printed cubes used in this study can be seen in

Fig 2: An image of the 3D printed cubes with the Line, Grid and Gyroid infill patterns and increasing infill percentage. The positioning of the cubes is identical to the one in Figure 1.

A slice from the 120 kV scan of the 3D printed cubes can be seen in

Fig 3: Figure 3. Screenshot of the CT scanned 3D printed cubes. The positioning of the cubes is identical to the one shown in Figure 1 and Figure 2.

No noticeable visible differences were observed among the imaged cubes across the three energy levels.

The evaluation demonstrated a clear relationship between infill percentage and HU values, where an increase in infill percentage corresponded to an increase in HU. Additionally, variations in HU were observed between different infill patterns, even at the same infill percentage. Furthermore, it was noted that 100% infill does not necessarily result in a completely solid object, as the degree of solidity is dependent on the infill pattern. These findings are clearly illustrated in

Fig 4: Results obtained from the measurements for the Line infill pattern.

for the Line infill,

Fig 5: Results obtained from the measurements for the Grid infill pattern.

for the Grid infill, and

Fig 6: Results obtained from the measurements for the Gyroid infill pattern.

for the Gyroid infill.

It was observed that cubes with the Gyroid infill pattern exhibited higher HU values compared to the other two infill patterns at the same infill percentage, whereas the Grid infill pattern resulted in the lowest measured HU values.

The influence of the scanning energy was also examined. Higher energy levels resulted in a decrease in the HU values of the cubes, which was consistent across all three infill patterns. This suggests a material-dependent effect, while the infill pattern itself does not appear to influence the HU values with changes in energy.