title: Effect of platelet-rich plasma on bone healing of autogenous bone grafts in critical-size defects.
abstract: OBJECTIVE
  This 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.
  
  
  METHODS
  Sixty 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).
  
  
  RESULTS
  Group 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).
  
  
  CONCLUSIONS
  Within 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.
authors.affiliation: Department of Surgery and Integrated Clinic, Division of Periodontics, Dental School of Araçatuba, São Paulo State University - UNESP, São Paulo, Brazil.
authors.forename: Maria J H
authors.initials: MJ
authors.lastname: Nagata
authors.forename: Luiz G N
authors.initials: LG
authors.lastname: Melo
authors.forename: Michel R
authors.initials: MR
authors.lastname: Messora
authors.forename: Suely R M
authors.initials: SR
authors.lastname: Bomfim
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Fucini
authors.forename: Valdir G
authors.initials: VG
authors.lastname: Garcia
authors.forename: Alvaro F
authors.initials: AF
authors.lastname: Bosco
authors.forename: Tetuo
authors.initials: T
authors.lastname: Okamoto
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects; D016025:Bone Transplantation / Q000502:physiology; D002122:Calcium Chloride; D002469:Cell Separation / Q000379:methods; D002498:Centrifugation; D008297:Male; D019647:Oral Surgical Procedures / Q000379:methods; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D053657:Platelet-Rich Plasma; D011817:Rabbits; D011897:Random Allocation; D012886:Skull / Q000601:surgery
chemical_list: D010982:Platelet-Derived Growth Factor; D002122:Calcium Chloride