Histochemical and radiological study of bone regeneration by the combinatorial use of tetrapod-shaped artificial bone and collagen

The purpose of this study was to examine the potential application of a tetrapod-shaped artificial bone, Tetrabone (TB), along with collagen, in bone regeneration. Nine-week-old male Wistar rats (n = 60) were used. An 8 mm-diameter defect was filled with TB, collagen, or a combination mixture of TB and collagen, and left untreated in the control group. The results showed higher volumes of the newly formed bones in the combination group than in the TB group or control group at each time point by micro-CT analysis (P < 0.05). The TB group showed bone formation that extended from the existing bone. In contrast, the collagen group showed disseminated bone formation in the defect. Runx2- and TGF-β-positive cells were identified at collagen and TB surfaces. The bone formation of the combination group had characteristics of both TB and collagen groups. The combination group showed bone formation from the existing bone edge and in the entire part of the defect. Thus, the combinatorial use of TB and collagen would be an effective strategy for the treatment of bone defect.