title: Periodontal wound healing with and without platelet-rich plasma: histologic observations and assessment of flap tensile strength.
abstract: BACKGROUND
  Platelet-rich plasma (PRP) has been promoted as a surgical adjunct to enhance hard and soft tissue wound healing. Although anecdotally reported to be of value, the results of controlled studies examining the added effects of PRP on surgical procedures have been mixed. The purpose of this study was to test the effect of PRP on flap strength at various post-surgical time points in a minipig animal model.
  
  
  METHODS
  Twelve Yucatan minipigs provided four sites per animal. PRP was prepared from each animal at the time of surgery. Following reflection of a mucoperiosteal flap in each quadrant, subgingival plaque and calculus were removed. Each surgical site was irrigated with sterile saline; prior to suturing, one randomly selected test quadrant in each arch was treated with PRP. Four animals were euthanized at day 14, and two animals were euthanized at 2, 7, 10, and 28 days. The flap strength in each quadrant was tested by attaching to a loop of 3-0 silk suture through the tissue; the force required to separate the flap from the tooth/bone interface was recorded for each site. A separate portion of each flap site was prepared for descriptive histologic examination, including inflammation, hemorrhage, and new bone growth.
  
  
  RESULTS
  Flap strength was significantly less on day 2 compared to later time points, and there were no significant differences between the test and control groups. No histologic differences in healing between test and control sites were seen at any time point.
  
  
  CONCLUSIONS
  PRP did not seem to contribute to greater flap strength at any post-surgical time point, nor was it associated with any histologic differences in wound healing in this Yucatan minipig model. The time points chosen for observation post-surgery, as well as the variability in the PRP platelet count, may have contributed to the lack of positive findings in this study.
authors.affiliation: Currently, private practice, Anchorage, AK; previously, U.S. Air Force Periodontics Residency, Wilford Hall Medical Center, Lackland Air Force Base, TX. USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Powell
authors.forename: Sharon R
authors.initials: SR
authors.lastname: Bannister
authors.forename: Scott A
authors.initials: SA
authors.lastname: Mackey
authors.forename: Steven C
authors.initials: SC
authors.lastname: Maller
authors.forename: Howard T
authors.initials: HT
authors.lastname: McDonnell
authors.forename: David E
authors.initials: DE
authors.lastname: Deas
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003728:Dental Calculus / Q000628:therapy; D003773:Dental Plaque / Q000628:therapy; D004195:Disease Models, Animal; D004487:Edema / Q000473:pathology; D005260:Female; D005337:Fibrin / Q000032:analysis; D005881:Gingiva / Q000473:pathology / Q000601:surgery; D005891:Gingivitis / Q000473:pathology; D009336:Necrosis; D010006:Osteoblasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D010519:Periodontium / Q000473:pathology / Q000601:surgery*; D053657:Platelet-Rich Plasma; D019106:Postoperative Hemorrhage / Q000473:pathology; D011897:Random Allocation; D013314:Stress, Mechanical; D013357:Subgingival Curettage / Q000379:methods; D013524:Surgical Flaps; D013536:Suture Techniques; D013552:Swine; D013556:Swine, Miniature; D013718:Tensile Strength; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology
chemical_list: D005337:Fibrin