| dc.description.abstract | Background: Bone grafting materials are commonly used in dentistry for a variety of surgical procedures and new materials are regularly being developed. Evaluation of these newly developed materials has been done in animal models using a calvarial defect. This study was done to test the effectiveness of an emerging material, PFI-2, for bone grafting and to compare two surgical techniques in a rat model including the calvarium osteotomy and tooth extraction defect.
Methods: Thirty two Wistar rats were divided into two groups: the tooth extraction group and the calvarium osteotomy group. The two surgical groups were divided into a control and test group. The control group had the surgical procedure performed without any grafting material while the test group had a PFI-2 scaffold placed into the bony defects. All other surgical methods were the same between the control and test group. Fluorochrome labels were used to identify new bone formation in ground sections. Animals were sacrificed at 4 and 8 weeks for evaluation using radiographs, micro-CT, histology, and RT-PCR.
Results: New bone formation was observed with both surgical techniques. PFI-2 induced 81.7% bone formation at eight weeks compared to 44.5% in the eight week control group. Histologic sections showed greater amounts of new bone formation in the PFI-2 groups with mesenchymal cell proliferation at primary ossification centers. RT-PCR was used to evaluate gene expression. In the extraction model, collagen 3, OCN, and ALP were significantly increased with a significant decrease in RunX2, and iBSP. In the calvarium model, collagen 1, RunX2, and ALP were significantly increased compared to corresponding controls.
Conclusions: PFI-2 induced new bone formation with 81.7% defect coverage compared to 44.5% in the control group. The extraction model and calvarium model produced significantly different responses in gene expression suggesting different molecular pathways in two surgical groups. Use of PFI-2 shows promise as a bioactive material for alveolar ridge augmentation and bone regeneration. | en |
