Gene expression and micro-computed tomography analysis of grafed bone using deprotenized bovine bone and freeze-dried human bone

Abstract

Objectives: Bio-Oss® and DFDBA are two commercial bone grafts that have been associated with clinical success for many years. However, there are few in vivo studies regarding their healing mechanism. The purpose of this study was to investigate bone forming characteristics and gene expression in mouse calvarium at 1 and 3 months after bone grafting with deproteinized bovine bone and freeze-dried human bone, and compare them to natural bone healing.

Methods: Thirty-six mice were divided into three groups (n = 6/group) according to the type of bone graft used: group 1 (control) -an empty defect without bone graft, group 2 - treatment with deproteinized bovine xenograft (Bio-Oss®) and group 3 - treatment with freeze-dried bone allograft (DFDBA). The bone graft was inserted into two 3-mm calvarium defects created on both sides of the parietal bone. At 1 and 3 months, the mice were dissected, and bone volume was evaluated using micro-CT and gene expression analysis.

Results: Micro-CT analysis demonstrated that the parietal bone of mice grafted with Bio-Oss® had significantly greater bone volume than both the DFDBA and control groups at both 1 and 3 months. The bone marker genes were increased in both Bio-Oss® and DFDBA groups at 3 months. Runx2 and Osx had significantly higher expression in the Bio-Oss® and DFDBA group compared to the control at 3 months.

Conclusion: These results showed that both bone graft materials promoted bone regeneration. Bio-Oss® demonstrated high osteoconductive properties.