title: Effect of hydroxyapatite on critical-sized defect.
abstract: BACKGROUND
  Xenologous or synthetic graft materials are commonly used as an alternative for autografts for guided bone regeneration. The purpose of this study was to evaluate effectiveness of carbonate apatite on the critical-size bone defect of rat's calvarium.
  
  
  METHODS
  Thirty-six critical-size defects were created on 18 adult male Sprague-Dawley rat calvaria under general anesthesia. Calvarial bones were grinded with 8 mm in daimeter bilaterally and then filled with (1) no grafts (control,n= 10 defects), (2) bovine bone mineral (Bio-Oss®, Geistlich Pharma Ag. Swiss,n= 11 defects), and (3) hydroxyapatite (Bongros®, Bio@ Inc., Seongnam, Korea,n= 15 defects). At 4 and 8 weeks after surgery, the rats were sacrificed and all samples were processed for histological and histomorphometric analysis.
  
  
  RESULTS
  At 4 weeks after surgery, group 3 (42.90 ± 9.33 %) showed a significant difference (p< 0.05) compared to the control (30.50 ± 6.05 %) and group 2 (28.53 ± 8.62 %). At 8 weeks after surgery, group 1 (50.21 ± 6.23 %), group 2 (54.12 ± 10.54 %), and group 3 (50.92 ± 6.05 %) showed no significant difference in the new bone formation.
  
  
  CONCLUSIONS
  Bongros®-HA was thought to be the available material for regenerating the new bone formation.
authors.affiliation: Graduate School of Dentistry, Chosun University, Gwangju, South Korea.
authors.forename: Ryoe-Woon
authors.initials: RW
authors.lastname: Kim
authors.affiliation: Graduate School of Dentistry, Chosun University, Gwangju, South Korea.
authors.forename: Ji-Hyoung
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Chosun University, 309, Pilmun-daero, Dong-gu, 501-759 Gwangju, South Korea.
authors.forename: Seong-Yong
authors.initials: SY
authors.lastname: Moon
keywords: Artificial Bone; Bone graft; Bovine bone; Hydroxyapatite; Xenograft