CD34+-progenitor-cells are essential for the growth and differentiation of cells within the bone marrow microenvironment. Objectives: To compare the quantity and the effect of CD34+-progenitor-cells on the craniofacial bone repair induced by PRP. Methods: Three linear bone defects (8 × 2 mm) were prepared in the calvaria of 16 rabbits. Each defect received either: (I) – 100 mL of PRP+autograft, (II) – 100 mL of PRP and (III) - blood clot (control). New bone tissue, granulation tissue and medullar area were evaluated by histomorphometric methods, while CD34+-progenitor-cells were evaluated by immunohistochemistry after 2 and 6 weeks post surgery. Data were analyzed by ANOVA and Student-Newman-Keuls (α = 5%). Results: The results are shown in the table. For both time periods analyzed larger areas of new bone formation in control group were observed, while the PRP groups showed higher values for medullar and granulation tissue areas. These results coincided with enhanced of CD34+-progenitor-cells/mm2. Conclusion: PRP induced the chemotaxis of CD34+-progenitor-cells and enhanced the medullar area on craniofacial bone repair.
Average ± standard deviation values of histomorphometric and immunohistochemistry analyses for all groups and time periods.
| PRP+autograft | PRP | Blood clot | |
2 weeks | Granulation tissue | 3.09±0.86+ | 11.25±1.10+++ | 9.30 ± 1.45 ++ |
Bone matrix | 6.59±0.66+ | 3.49±1.07++ | 6.70 ± 1.45+ | |
Medullar area | 6.45±0.58+ | 1.07±0.71++ | - | |
CD34+ cells/mm2 | 239.13±51.98++ | 289.38±40.63++ | 87.38±20.15+ | |
6 weeks | Granulation tissue | 0.85±0.29+ | 4.50±1.17++ | 0.49±0.41+ |
Bone matrix | 7.35±0.98++ | 6.40 ± 0.43++ | 10.90±1.04++ | |
Medullar area | 7.90±0.77++ | 5.10±0.98+ | 4.70±0.68+ | |
CD34+ cells/mm2 | 30.13±20.14++ | 82.13±19.78++ | 0.82±0.04+ | |
For each line, values followed by the same superscript are statistically similar, p > 0.05.