Comparison of osteogenic potential of calvarial bone dust, bone fragments, and periosteum

Bone dust is often used as a control when testing the potential of a new reconstructive graft material. Under microscopic examination, it would be expected to see the fully differentiated cellular components of bone, but instead only fusiform shapes characteristic of fibroblasts are mainly seen. This study aimed to compare the osteogenic potential of cells obtained from calvarial bone dust, bone fragments, and periosteum using 3 assays: collagen, calcium, and alkaline phosphatase.

Bone dust was harvested from the calvaria of 5 euthanized rabbits by drilling burr holes. Small pieces of intact, nondrilled bone, and periosteum were also obtained to serve as controls. The cells obtained from the bone dust, bone fragments, and periosteum were cultured for 5 weeks and then assayed for collagen (type 1), calcium, and alkaline phosphatase.

Staining for calcium revealed that the greatest calcium deposition was achieved with periosteum, followed by bone dust and then bone fragments. Staining for alkaline phosphatase was similar for bone dust and periosteum, followed by bone fragments. Collagen assay demonstrated the presence of collagen in similar concentrations in all 3 preparations.

Bone dust has most of the necessary components for osteogenesis, including the presence of osteoprogenitor cells that have the ability to lay down collagen type 1 and deposit calcium and can differentiate to form bone. Further studies that can accurately quantify the percentage of surviving osteoblasts in various bone components are needed.