The regenerated bone quality by implantation of octacalcium phosphate collagen composites in a canine alveolar cleft model

Objective: Synthetic octacalcium phosphate and porcine atelocollagen composites significantly enhanced bone regeneration more than b-tricalcium phosphate collagen composite and hydroxyapatite collagen composite in a rat cranial defect model. However, the long-term stability and quality of octacalcium phosphate collagen (OCP/Col) composites-derived regenerated bone, when implanted in a canine alveolar cleft model, have yet to be elucidated. The present study investigated the longterm stability and quality of bone regenerated by OCP/Col. Design: Disks of OCP/Col or collagen were implanted in a canine alveolar-cleft model (n=6). Then, bone regeneration in the implanted areas was investigated macroscopically, radiographically, and histologically at 10 months after implantation. In addition, three-dimensional quantitative images of regenerated bone were analyzed by microcomputed tomography. Results: Macroscopically, the OCP/Col treated alveolus was clearly augmented, and radioopacity in the OCP/Col implanted area was comparable to that of the original alveolus bone. On histological analysis, the area was mostly filled with newly formed bone, and a few granules of implanted OCP/Col were enclosed in it. In the microcomputed tomography analysis, the regenerated bone volume in the OCP/Col group was larger than that in the collagen group. OCP/ Col-derived bone consisted of outer cortical and inner cancellous structure with dense trabeculae and seemed like the original bone structure. Conclusions: OCP/Co composites could be a useful bone regenerative material to substitute for autogenous bone because their implantation could elicit high bone regeneration and active structural reconstitution.