The present publication reports the purification effort of two natural bone blocks, that is, an
allogeneic bone block (maxgraft®, botiss biomaterials GmbH, Zossen, Germany) and a xenogeneic
block (SMARTBONE®, IBI S.A., Mezzovico-Vira, Switzerland) in addition to previously published
results based on histology. Furthermore, specialized scanning electron microscopy (SEM) and in vitro
analyses (XTT, BrdU, LDH) for testing of the cytocompatibility based on ISO 10993-5/-12 have been
conducted. The microscopic analyses showed that both bone blocks possess a trabecular structure
with a lamellar subarrangement. In the case of the xenogeneic bone block, only minor remnants of
collagenous structures were found, while in contrast high amounts of collagen were found associated
with the allogeneic bone matrix. Furthermore, only island-like remnants of the polymer coating
in case of the xenogeneic bone substitute seemed to be detectable. Finally, no remaining cells or
cellular remnants were found in both bone blocks. The in vitro analyses showed that both bone
blocks are biocompatible. Altogether, the purification level of both bone blocks seems to be favorable
for bone tissue regeneration without the risk for inflammatory responses or graft rejection. Moreover,
the analysis of the maxgraft® bone block showed that the underlying purification process allows
for preserving not only the calcified bone matrix but also high amounts of the intertrabecular
collagen matrix.