969 resultados para Bone regeneration, Bone defect, Platelet-rich plasma, Collagen, Animal model, Sheep


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Background and objective: The purpose of this study was to analyze histologically the influence of autologous platelet-rich plasma on bone healing in surgically created critical-size defects in rat calvaria.Material adn Methods: Thirty-two rats were divided into two groups: the control group (group C) and the platelet-rich plasma group. An 8-mm-diameter critical-size defect was created in the calvarium of each animal. In group C the defect was filled by a blood clot only. In the platelet-rich plasma group, 0.35 mL of platelet-rich plasma was placed in the defect and covered by 0.35 mL of platelet-poor plasma. Both groups were divided into subgroups (n = 8) and killed at either 4 or 12 wk postoperatively. Histometric (using image-analysis software) and histologic analyses were performed. The amount of new bone formed was calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for statistical analysis (analysis of variance, Tukey, p < 0.05).Results: No defect completely regenerated with bone. The platelet-rich plasma group had a statistically greater amount of bone formation than group C at both 4 wk (17.68% vs. 7.20%, respectively) and 12 wk (24.69% vs. 11.65%, respectively) postoperatively.Conclusion: Within the limits of this study, it can be concluded that platelet-rich plasma placed in the defects and covered by platelet-poor plasma significantly enhanced bone healing in critical-size defects in rat calvaria.

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To evaluate the bone healing of defects filled with particulate bone graft in combination with platelet-rich plasma (PRP), added with a mixture of calcium chloride and thrombin or just calcium chloride. Two 5-mm bone defects were created in the calvaria of 24 rabbits. Each defect was filled with particulate bone graft and PRP. In one defect the PRP was activated by a mixture of calcium chloride and thrombin; in the other, PRP was activated by calcium chloride only. The animals were euthanized 1, 2, 4, and 8 weeks after the surgeries, and the calvaria was submitted to histologic processing for histomorphometric analysis. The qualitative analysis has shown that both defects presented the same histologic characteristics so that a better organized, more mature, and well-vascularized bone tissue was noticed in the eighth week. A good bone repair was achieved using either the mixture of calcium chloride and thrombin or the calcium chloride alone as a restarting agent of the coagulation process.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The purpose of this study was to evaluate the effects of the platelet-rich plasma (PRP) when used in combination with autogenous bone graft and bioabsorbable membrane (Resolut® ) in the treatment of Class  III furcation defects in dogs. Material and method: Class III furcation defects (5 mm in height and in depth) were surgically created in the mandibular third premolars of five mongrel dogs. After nine weeks, the lesions were treated with scaling and root planning and each defect received one of the following treatments: autogenous bone graft + membrane (group C) or PRP + autogenous bone graft + membrane (group T). After a healing period of 90 days, the animals were sacrificed. Routine histological processing and staining with hematoxilyn and eosin and Masson trichrome were performed and a histomorphometric analysis determined the effect of the treatments on periodontal tissue regereneration. Data were analyzed by Hotelling’s T-squared (p < 0.05). Result: No statistically significant difference between C and T groups was observed by the histomorphometric analysis of the furcation area. Both treatment groups demonstrated similar regenerative results with the furcation defects partially filled and periodontal regeneration limited to the experimental notches of the lesions. (p > 0.05). Conclusion: According to the present results, PRP does not enhance the periodontal regeneration in class III furcation defects treated with autogenous bone graft and bioabsorbable membrane.

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The purpose of this study was to analyze histologically the influence of platelet-rich plasma (PRP) coagulated with two different activators on bone healing in surgically created critical-size defects (CSD) in rat calvaria.Forty-eight rats were divided into three groups: C, PRP-C and PRP-T. An 8 mm diameter CSD was created in the calvarium of each animal. In group C, the defect was filled by a blood clot only. In groups PRP-C and PRP-T, the defect was filled with PRP activated with either calcium chloride or thromboplastin solution, respectively. Each group was divided into two subgroups (n = 8 per subgroup) and killed at either 4 or 12 weeks postoperatively. Histologic and histometric analyses were performed. The amount of new bone formed was calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for statistical analysis (analysis of variance, Tukey's post hoc test, p < 0.05).No defect completely regenerated with bone. Group PRP-C had a statistically greater amount of bone formation than groups C and PRP-T at both time points of analysis. No statistically significant differences were observed between groups C and PRP-T.It can be concluded that the type of activator used to initiate PRP clot formation influences its biological effect on bone healing in CSD in rat calvaria.

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AimThis study histologically analysed the effect of autogenous platelet-rich plasma (PRP), prepared according to a new semiautomatic system, on healing of autogenous bone (AB) grafts placed in surgically created critical-size defects (CSD) in rabbit calvaria.Material and MethodsSixty rabbits were divided into three groups: C, AB and AB/PRP. A CSD was created in the calvarium of each animal. In Group C (control), the defect was filled by blood clot only. In Group AB (autogenous bone graft), the defect was filled with particulate autogenous bone. In Group AB/PRP (autogenous bone graft with platelet-rich plasma), it was filled with particulate autogenous bone combined with PRP. All groups were divided into subgroups (n=10) and euthanized at 4 or 12 weeks post-operatively. Histometric and histologic analyses were performed. Data were statistically analysed (anova, t-test, p < 0.05).ResultsGroup C presented significantly less bone formation compared with Group AB and AB/PRP in both periods of analysis (p < 0.001). At 4 weeks, Group AB/PRP showed a statistically greater amount of bone formation than Group AB (64.44 +/- 15.0% versus 46.88 +/- 14.15%; p=0.0181). At 12 weeks, no statistically significant differences were observed between Groups AB and AB/PRP (75.0 +/- 8.11% versus 77.90 +/- 8.13%; p > 0.05). It is notable that the amount of new bone formation in Group AB/PRP at 4 weeks was similar to that of Group AB at 12 weeks (p > 0.05).ConclusionWithin its limitation, the present study has indicated that (i) AB and AB/PRP significantly improved bone formation and (ii) a beneficial effect of PRP was limited to an initial healing period of 4 weeks.

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Purpose: This study histomorphometrically analyzed the effect of autogenous platelet-rich plasma (PRP) on healing of fresh frozen bone allograft (FFBA) in bony defects in rat calvaria. Materials and Methods: A 5mm-diameter defect was created in the calvarium of 30 rats. Animals were divided into three groups: C (defect was filled by blood clot only), FFBA (defect was filled with 0.01mL of FFBA), and FFBA/PRP (defect was filled with 0.01mL of FFBA combined with 100μL of PRP). All animals were euthanized at 30 days postoperatively. Histomorphometry and histology analyses were performed. Data were statistically analyzed (analysis of variance, Tukey, p<.05). Results: FFBA had a statistically smaller new bone area than groups FFBA/PRP and C. No statistically significant differences were observed between groups FFBA and FFBA/PRP with regard to remaining bone graft particle area. Conclusion: It can be concluded that (1) PRP improved the incorporation of FFBA, increasing the amount of new bone formed; (2) PRP has not influenced the resorption of nonviable particles of the FFBA; and (3) presence of remaining FFBA particles might have accounted for the smaller amount of new bone observed in group FFBA when compared with control group. © 2011 Wiley Periodicals, Inc.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objective. The objective of this study was to histologically analyze the influence of the platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in the calvaria of diabetic rats.Study design. A total of 20 diabetic rats were divided into 2 groups: C (control) and PRP. A 5-mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group PRP, 0.35 mL of PRP was placed in the defects. All animals were humanely killed 30 days postoperatively. Histometric and histologic analyses were performed. Data were statistically analyzed (t test, P < .05).Results. No defect completely regenerated with bone. Group PRP had a statistically greater amount of bone formation than Group C (37.22% +/- 6.00% and 21.68% +/- 11.35%, respectively).Conclusion. PRP placed in the defects significantly enhanced bone healing in CSD in the calvaria of diabetic rats both qualitatively and quantitatively. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: 72-78)

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The aim of this study was to evaluate the effect of platelet rich plasma (PRP) associated to bovine inorganic bone (Bio-Oss®; Geistlich) or bioactive glass (Bio-Gran®; Orthovita, Implant Innovations) on bone healing. Bone cavities were prepared in both sides of the mandible of 4 adult male dogs. The cavities were divided into 4 groups according to the filling material as follows: control, PRP, PRP/Bio-Oss, PRP/Bio-Gran. The animals were sacrificed after 120 days and histological and histomorphometrical analysis was performed. The control group showed 80.6% of bone formation in the longitudinal sections at 6 mm depth and 83.7% at 13 mm depth. The transverse sections displayed 74.2% at both 6 and 13 mm depths. The PRP group showed 21.1% of bone formation in the longitudinal sections at 6 mm depth, and 23.1% at 13 mm depth. The transverse sections presented 28.98% of bone formation at 6 mm depth and 41.2% at 13 mm depth. The PRP/Bio-Gran group showed 25.1% of bone formation in the longitudinal sections at 6 mm depth and 30.4% at 13 mm depth. In the transverse sections, the bone formation was 43.0% at 6 mm depth and 39.7% at 13 mm depth. The PRP/Bio-Oss group showed 35.5% of bone formation in the longitudinal sections at 6 mm depth and 42% at 13 mm depth. In the transversal sections, the bone formation was 26.8% and 31.2% at the depths of 6 and 13 mm, respectively. PRP alone or associated with bovine inorganic bone or bioglass had no significant effect in bone healing.

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This study evaluated the effects of homogenous demineralized dentin matrix (HDDM) slices and platelet-rich plasma (PRP) in surgical defects created in the parietal bones of alloxan-induced diabetic rabbits, treated with a guided bone regeneration technique. Biochemical, radiographic, and histological analyses were performed. Sixty adult New Zealand rabbits were divided into five groups of 12: normoglycaemic (control, C), diabetic (D), diabetic with a PTFE membrane (DM), diabetic with a PTFE membrane and HDDM slices (DM-HDDM), and diabetic with PTFE membrane and PRP (DM-PRP). The quantity and quality of bone mass was greatest in the DM-HDDM group (respective radiographic and histological analyses: at 15 days, 71.70±16.50 and 50.80±1.52; 30 days, 62.73±16.51 and 54.20±1.23; 60 days, 63.03±11.04 and 59.91±3.32; 90 days, 103.60±24.86 and 78.99±1.34), followed by the DM-PRP group (respective radiographic and histological analyses: at 15 days 23.00±2.74 and 20.66±7.45; 30 days 31.92±6.06 and 25.31±5.59; 60 days 25.29±16.30 and 46.73±2.07; 90 days 38.10±14.04 and 53.38±9.20). PRP greatly enhanced vascularization during the bone repair process. Abnormal calcium metabolism was statistically significant in the DM-PRP group (P<0.001) for all four time intervals studied, especially when compared to the DM-HDDM group. Alkaline phosphatase activity was significantly higher in the DM-HDDM group (P<0.001) in comparison to the C, D, and DM-PRP groups, confirming the findings of intense osteoblastic activity and increased bone mineralization. Thus, HDDM promoted superior bone architectural microstructure in bone defects in diabetic rabbits due to its effective osteoinductive and osteoconductive activity, whereas PRP stimulated angiogenesis and red bone marrow formation.