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Purpose: The collection of autologous platelet-rich plasma (PRP) has demonstrated favorable affects on wound healing in compromised patients. The purpose of this study was to evaluate the expression of PDGF, bFGF, and TGF-beta in irradiated and nonirradiated bone in a rabbit tibia model and the ability of PRP to increase growth factor expression when added to autogenous bone graft in a rabbit cranial defect model., Materials and Methods: Ten New Zealand White rabbit tibiae and calvariae were utilized for this study. Tibiae were irradiated at 60 to 70 cGy and evaluated for expression of PDGF, bFGF, and TGF-beta. Rabbit calvariae were also analyzed after grafting with autogenous bone and PRP for determination of growth factor expression., Results: Decreased expression of PDGF, bFGF, and TGF-beta was seen in cortical and cancellous bone samples when irradiated bone was compared to nonirradiated rabbit tibiae. An increase in PDGF, bFGF, and TGF-beta expression was detected in cortical autogenous bone grafts with PRP at 1 and 2 months compared to autogenous bone alone., Discussion: In this study, growth factors, which were decreased in irradiated cortical and cancellous bone, showed increased expression at 1 and 2 months when PRP was added to autogenous bone grafts. Thus, PRP may have potential therapeutic applications when bone grafting is required in patients with reduced bone vascularity, including patients with previous head and neck irradiation, diabetes, and smoking habits., Conclusions: Decreased expression of PDGF, bFGF, and TGF-beta was seen in radiated rabbit tibia as compared to nonirradiated controls, and increased expression of these growth factors was seen in PRP-containing autogenous bone grafts.

Platelet-rich plasma (PRP) offers a new and potentially useful adjunct to allograft materials in oral and maxillofacial bone and implant reconstructive surgery. This study compares bone healing in four cranial defects in the rabbit grafted with freeze-dried mineralized bone (FMB) alone, FMB+PRP, freeze-dried demineralized bone (FDDB) alone, and FDDB+PRP. Fifteen New Zealand white rabbits were included in this randomized, blind, prospective pilot study. Four equal 8 mm diameter defects were created in each rabbit cranium and immediately grafted with the above materials. Five rabbits were evaluated at 1, 2, and 4 months. Radiographically, FMB+PRP showed a tendency toward increased bone density over FMB alone, but was not statistically significant (P>0.05), and FDDB+PRP showed a tendency toward increased bone density over FDDB alone, but was not statistically significant (P>0.05). Histomorphometrically, FMB+PRP showed a tendency toward increased bone area over FMB alone at 1 and 4 months, but was not statistically significant (P>0.05), and FDDB+PRP showed a tendency toward increased bone area over FDDB alone, at 1 and 2 months, but was not statistically significant (P>0.05). This study failed to show a radiographic or histomorphometric increase in bone formation with the addition of PRP to either FMB or FDDB in non-critical-sized defects in the rabbit cranium.

Purpose: Platelet-rich plasma (PRP) is potentially useful as an adjunct to allograft and xenograft materials in oral and maxillofacial bone and implant reconstructive surgery. This study compares bone healing and formation in 4 cranial defects in rabbits grafted with autogenous bone, xenograft, and xenograft with PRP (with a no-graft group as a control)., Materials and Methods: Fifteen New Zealand white rabbits were included in this randomized, blind, prospective pilot study. Four identical 8-mm-diameter defects were created in each rabbit cranium and immediately grafted with the above materials. Five rabbits were evaluated at 1 month, 5 at 2 months, and 5 at 4 months. Radiographs were used to evaluate bone density., Results: Radiographically, sites at which Bio-Oss, autogenous bone, and Bio-Oss + PRP were grafted showed a significant increase in bone density at 1 month (P = .05 for Bio-Oss, P = .02 for autogenous bone, P = .008 for Bio-Oss + PRP) and at 4 months (P = .02 for Bio-Oss, P = .04 for autogenous bone, P = .05 for Bio-Oss + PRP). Autogenous bone sites (P < .001) and Bio-Oss + PRP sites (P < .001) also showed significant increases at 2 months. Histomorphometrically, autogenous bone sites showed a significantly greater increase than control sites (P = .08 at 1 month, P = .03 at 2 months, P = .01 at 4 months), Bio-Oss sites (P < .001 at all 3 evaluation points), or Bio-Oss + PRP sites (P = .009 at 1 month, P = .02 at 2 months, P = .01 at 4 months). Furthermore, Bio-Oss + PRP sites showed a significantly greater increase in bone area at 1, 2, and 4 months than Bio-Oss alone (P = .003 at 1 month, P = .02 at 2 months, P = .006 at 4 months)., Discussion: Radiographs showed significantly greater bone density at the Bio-Oss, autogenous bone, and Bio-Oss + PRP sites than at control sites at nearly every point in time evaluated; however, clinical significance is difficult to determine, since all materials appeared dense on the radiograph. Histomorphometry showed that the increase in bone area at autogenous sites was significantly greater than that seen with other grafting materials or at the control sites., Conclusion: This study showed a histomorphometric increase in bone formation with the addition of PRP to Bio-Oss in non-critical-sized defects in the rabbit cranium.