Preliminary evaluation of BMP-2-derived peptide in repairing a peri-implant critical size defect: A canine model

Abstract

A synthetic bone morphogenetic protein (BMP)-2-derived peptide has been discovered to promote bone regeneration. The present study investigated the potential of the BMP-2 peptide combined with hydroxyapatite (HAp)/β-tricalcium phosphate (TCP)/collagen (Col) composite in repairing a peri-implant critical size defect. Twenty-four saddle-type alveolar defects (10mm mesiodistally and 4mm apicocoronally) were surgically prepared in edentulous ridges in four male beagle dogs. Following implant placement, the defects with vertically exposed implant fixtures received (a) HAp/TCP/Col composite, (b) HAp/TCP/Col+4mg/mL BMP-2 peptide, (c) HAp/TCP/Col+20mg/mL BMP-2 peptide, or (d) HAp/TCP/Col+0.2mg/mL recombinant human BMP-2 (rhBMP-2). Bone regeneration and mineralization were assessed using radiography, micro-computed tomography (micro-CT), fluorescence labeling, and histologic analyses after healing for 4 or 8 weeks. Implant stability was measured using resonance frequency analysis. The 20mg/mL BMP-2 peptide groups demonstrated a distinguishable advantage in bone regeneration potential over the control groups, as observed on radiographic imaging and histologic examination, although no significant difference was found in implant stability and histomorphometric analysis of mineralization levels. However, the performance of the 20mg/mL BMP-2 peptide groups were inferior to that of the 0.2mg/mL rhBMP-2 groups. The BMP-2 peptide may accelerate peri-implant bone regeneration. The BMP-2 peptide at 20mg/mL still cannot complete bone repair of peri-implant critical size defect. The BMP-2 peptide at 20mg/mL has similar osteoinductive performance to the rhBMP-2 at 0.02mg/mL.