Effect of platelet-released growth factors and collagen type I on osseous regeneration of mandibular defects. A pilot study in minipigs.
OBJECTIVE
To study the effects of platelet-released growth factors (PRGF) and collagen type I on bone defect healing in minipig mandibles.


METHODS
In eight adult minipigs defects were trephined in the facial mandibular wall from extra-oral and filled with collagen+PRGF or with collagen alone. Control defects were left untreated. PRGF were defined as the supernatants obtained after centrifugation of washed, thrombin-activated allogenic cells of platelet-rich plasma. The animals were sacrificed at 4 and 8 weeks. For histological analysis, undecalcified ground specimens stained with the Levai-Laczko stain were used.


RESULTS
For the entire follow-up, the amount of newly formed bone was 35.49 +/- 3.84% in the collagen+PRGF group, 46.34 +/- 3.84% in the collagen-only group and 33.83 +/- 4.11% in the controls. The differences between the collagen+PRGF and the collagen-only group (p = 0.0343), and between the collagen-only group and the controls (p = 0.0305) were significant. Histologically, defects filled with collagen+PRGF showed inflammatory reactions at 4 weeks, and new bone formation near the remnants of the filler collagen was reduced.


CONCLUSIONS
The data suggest that collagen type I alone, but not its combination with PRGF can support the early stages of cortical bone repair.
Department of Oral Surgery, University of Vienna School of Dentistry, Vienna, Austria. gabor.fuerst@univie.ac.at
Gabor
G
Fuerst
Gruber
G
Reinhard
Stefan
S
Tangl
Martina
M
Mittlböck
Fidel
F
Sanroman
Georg
G
Watzek
D000818:Animals; D001792:Blood Platelets; D001861:Bone Regeneration / Q000187:drug effects*; D024042:Collagen Type I / Q000494:pharmacology*; D004338:Drug Combinations; D005260:Female; D006133:Growth Substances / Q000494:pharmacology*; D016018:Least-Squares Analysis; D008297:Male; D008334:Mandible / Q000601:surgery; D010865:Pilot Projects; D010983:Plateletpheresis; D013552:Swine; D013556:Swine, Miniature
D024042:Collagen Type I; D004338:Drug Combinations; D006133:Growth Substances