Abstract:
Introduction. There are several types of grafts used in the treatment of bone defects [1]. During the
research, was tested the regeneration capacity of critical bone defects with several types of materials.
Materials and methods. To 18 New Zealand rabbits, under general anesthesia in both parietal bones,
8 mm in diameter critical defects were made. In the defects made in the right parietal bones were
transplanted (n=3): collagen sponges cross-linked with 25% glutaraldehyde (GA) vapours, collagen
sponges cross-linked with 25 mM riboflavin under UV-A [3], lamellas of demineralised bone matrix
(DBM), shredded DBM [2], and 3D printed PLA discs; the control materials were transplanted in
defects made in the left parietal bones: minced autologous iliac bone and Colapan. The rabbits were
removed from the experiment at 12 weeks, the calvarias were fixed in 10% buffered formaldehyde.
The regenerated defects were examined histologically by Hematoxylin-Eosin staining, and scanning
electron microscopy (SEM) [4].
Results. The histological examination of defects treated with minced autologous bone showed an
inflammatory process with necrosis and resorption of transplanted bone trabeculae. In defects treated
with Colapan formation of bone trabeculae in the areas of contact with the native bone was
determined. The defects treated with cross-linked collagen sponges showed a dense and regularly
distributed collagen fibers when using GA and degenerated, loose with thin fibrillar structure for
riboflavin. When DBM lamellas were used, debris of DBM matrix and disorganized fibrous
connective tissue with an infiltrative character were found. The shredded DBM fragments were
consolidated with fibrous tissue and at the periphery of the fragments, trabecular extensions of newly
formed bone were determined. In spaces between filaments of PLA discs were found thick collagen
fibers forming bundles and newly formed trabeculae of reticular fibrous bone. SEM showed that
transplanted materials changed significant their structure except the PLA discs.
Conclusions. The difference between the obtained results showed that not all materials can be used
for an efficient regeneration of critical bone tissue defects. Compared to the control and the other
experimental groups, shredded DBM at 12 weeks filled the defect with bone-like tissue.
