FIGURE 2.

Toluidine-blue stained MMA sections of middle sections from scaffold treated calvarial bone defects. Upon a healing period of 4 weeks, the scaffolds from tricalcium phosphate (TCP) are visible as blackish or dark blue areas. Bone ingrowth was most advanced in additively manufactured scaffolds with a pore diameter of 1.2 mm and bottleneck diameter of 1.0 mm (A). In scaffolds with a pore diameter of 1.5 mm and bottleneck diameter of 1.0 mm (B) bone growth did not extend far into the scaffolds. A scale bar, placed on top of the histologies is provided to show the 6 mm defect margins. In the lower panel, 2.5-fold higher magnifications are shown from the area marked in (A,B) to visualize bone tissue formation. The light blue-stained bone tissue is lamellar bone (also new, but later formed) on the initial woven bone structures stained dark blue and purple. Lacunae from osteocytes are visible.