ArrowBone™
Source: Hidemichi Kihara. Makoto Shiota, Yasuo Yamashita, Shohei Kasugai. : Biodegradation
Process of α-TCP Particles and New Bone Formation in a Rabbit Cranial Defect Model, J Biomed
Mater Res B: Appl Biomater 79(2): 284-291, 2006.
Microscopic view of a cross-section of a defect 1 week after implantation
Connective tissue and numerous capillaries are seen among the alpha-TCP
granules. Near the defect wall, newly formed bone is observed around the
surface of the alpha-TCP granules and some of the alpha-TCP granules and
the defect wall are partially connected with newly formed bone.
Microscopic view of a cross-section of a defect 4 weeks after implantation
The defect space is maintained, even in the center of the defect. The connective tissues first
observed at 1 week are reduced, and new bone in direct contact with the surface of the alpha-
TCP particles is observed among the alpha-TCP granules, even in the center of the defect. This demonstrates the good osteoconduction of the alpha-TCP granules. Near the defect wall, most
of the alpha-TCP granules are enclosed in new bone and have become smaller. In non-decalcified specimens, reticulate immature bone or bone-like structures surround the alpha-TCP particles
and a few osteoclasts are observed surrounding the alpha-TCP particles.
Microscopic view of a cross-section of a defect 8 weeks after implantation
The entire defect is filled with new bone and residual alpha-TCP particles, which are in the process
of being replaced by new bone, even in the center of the defect. The connective tissue among the
alpha-TCP particles is reduced more than at 4 weeks, and new bone substitution has progressed.
Reticulate new bone or bone-like structures are observed in the alpha-TCP particles in non-
decalcified specimens.
Most of the alpha-TCP particles near the defect wall have lost their original shape and become
smaller. At some distance from the defect wall, the alpha-TCP particles have various forms;
some have a concave surface into which new bone has entered and other particles have been
deeply invaded by new bone.
In non-decalcified specimens, the alpha-TCP particles are smaller than at 4 weeks and the
boundary between the alpha-TCP particles and surrounding new bone is indistinct, resulting
from the progressive collapse of alpha-TCP particles.
Source: Yamada M, Shiota M, Yamashita Y, Kasugai S. : Histological and Histomorphometrical
Comparative Study of the Degradation and Osteoconductive Characteristics of alpha-and beta-
Tricalcium Phosphate in Block Grafts. J Biomed Mater Res B Appl Biomater 2007;82(1):139-48.
