Bone graft ; Bone morphogenetic protein-2 ; Bone regeneration
Abstract
The aim of this study was to elucidate the influence of bone morphogenetic protein-2 (BMP-2)-loaded
hydroxyapatite (HA) carrier on a neighboring surgical defect in the rabbit calvarial defect model. Two circular bicortical
defects (8 mm in diameter) were created 2 mm apart on each rabbit calvarium (n=10 animals in each group). The
rabbits were randomly divided into two groups: BMP-2-loaded HA and HA only. Control defects were designated as
HAC (the sham surgical site located at the neighboring defect filled with HA only) and HAB (the sham surgical site
located at the neighboring defect filled with BMP-2-loaded HA). Twenty animals were sacrificed at 2 and 8weeks
postsurgery, and microcomputed tomographic, histologic, and histomorphometric evaluations were performed. The
HAC and HAB groups showed small amounts of new bone formation at both healing periods. Radiographic,
histologic, and histomorphometric features such as defect closure, new bone area, total augmented area, total
bone/new bone volume, and closure volume did not differ significantly between the two groups. When evaluating the
influence of BMP-2-loaded HA on a neighboring sham surgical site, inadvertent BMP-2 expression will not occur
when the circular defects are separated by at least 2 mm.