Journal of Dental Research, Vol 78, 1682-1687, Copyright © 1999 by International & American Associations for Dental Research Online Journals
Implantation of octacalcium phosphate (OCP) in rat skull defects enhances bone repair
S. Kamakura, Y. Sasano, H. Homma, O. Suzuki, M. Kagayama and K. Motegi
Department of Maxillofacial Surgery I, School of Dentistry, Tohoku University, Sendai, Japan.
Synthetic octacalcium phosphate (OCP) enhances bone formation if implanted
into the subperiosteal region of murine bone. Such implanted OCP may be
resorbed and replaced by bone with time. We hypothesized that OCP could be
used as an effective bone substitute. To test this hypothesis, we designed
the present study to investigate if bone repair in a rat skull defect is
enhanced by the implantation of OCP. Rats were divided into two groups:
OCP-treated animals and untreated controls. Six rats from each group were
fixed at 4, 12, and 24 weeks after implantation. A full-thickness
standardized trephine defect was made in the parietal bone, and synthetic
OCP was implanted into the defect. After being examined radiographically,
the specimens were decalcified and processed for histology. OCP
implantation significantly promoted bone repair compared with the controls.
A statistical analysis showed an increase in the area of radiopacity within
the skull defect between week 4 and week 12. Histologically, bone was
formed on the implanted OCP and along the defect margin at week 4. At week
12, the implanted OCP was surrounded by newly formed bone. At week 24, the
defect was almost completely filled with bone. In the control, bone
formation was observed only along the defect margin. The present results
demonstrate that OCP could be used as an effective bone substitute.
