title: The healing effect of platelet-rich plasma on xenograft in peri-implant bone defects in rabbits.
abstract: BACKGROUND
  The association of biomaterial combined with repair factor-like platelet-rich plasma (PRP) has prospective values. Bovine-derived xenograft has been identified as an osteoconductive and biocompatible grafting material that provides osseointegration ability. PRP has become a valuable adjunctive agent to promote healing in a lot of dental and oral surgery procedures. However, there are controversies with respect to the regenerative capacity of PRP and the real benefits of its use in bone grafts. The purpose of this study was to assess the influence of PRP combined with xenograft for the repair of peri-implant bone defects.
  
  
  METHODS
  Twelve rabbits were used in this study, and the experimental surgery with implant installation was performed simultaneously. Autologous PRP was prepared before the surgical procedure. An intrabony defect (7.0 mm in diameter and 3.0 mm deep) was created in the tibia of each rabbit; then, 24 titanium dental implants (3.0 mm in diameter and 8.5 mm long) were inserted into these osteotomy sites. Thus, a standardized gap (4.0 mm) was established between the surrounding bony walls and the implant surface. The gaps were treated with either xenograft alone (control group) or xenograft combined with PRP (experimental group). After healing for 1, 2, 3, 4, 5, and 6 weeks, the rabbits were sacrificed with an overdose of KCl solution. Two rabbits were killed at each time, and the samples including dental implants and surrounding bone were collected and processed for histological analysis.
  
  
  RESULTS
  More newly formed bone and a better bone healing process were observed in control group. The histomorphometric analysis revealed that the mean percentage of bone-to-implant contact in the control group was significantly higher than that of the experimental group (25.23 vs. 8.16 %;P< 0.05, independent-simplettest, analysis of variance [ANOVA]).
  
  
  CONCLUSIONS
  The results indicate that in the addition of PRP to bovine-derived xenograft in the repair of bone defects around the implant, PRP may delay peri-implant bone healing.
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Medicine, Inha University, Incheon, South Korea.
authors.forename: Wang
authors.initials: W
authors.lastname: Peng
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Medicine, Inha University, Incheon, South Korea.|Department of OMFS, Dentistry, College of Medicine, Inha University, #7-206, 3rd St. Shinheung-dong, Choong-gu, Incheon, 400-711 South Korea.
authors.forename: Il-Kyu
authors.initials: IK
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Medicine, Inha University, Incheon, South Korea.
authors.forename: Hyun-Young
authors.initials: HY
authors.lastname: Cho
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Medicine, Inha University, Incheon, South Korea.
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Seo
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Medicine, Inha University, Incheon, South Korea.
authors.forename: Dong-Hwan
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Medicine, Inha University, Incheon, South Korea.
authors.forename: Jun-Min
authors.initials: JM
authors.lastname: Jang
authors.affiliation: Department of Oral and Maxillofacial Surgery, International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon, South Korea.
authors.forename: Seung-Hoon
authors.initials: SH
authors.lastname: Park
keywords: Bone healing; Dental implant; Platelet-rich plasma; Rabbit; Xenograft