title: Bone formation with various bone graft substitutes in critical-sized rat calvarial defect.
abstract: OBJECTIVE
  This histomorphometric study compared the efficacy of a new bone graft substitute (N-HA) derived from hen eggshell, consisted of submicron scale porous hydroxyapatite structure, in the healing of 8 mm diameter critical size defects in rat calvaria. We compared N-HA alone or in combination with calcium sulfate (CS), with a commercial bone substitute, anorganic bovine bone (Bio-Oss, BO).
  
  
  METHODS
  Critical size defects were created in calvaria of 56 adult Sprague-Dawley rats. Animals were divided into four groups and treated with (1) unfilled defects, (2) N-HA grafts, (3) BO grafts and (4) N-HA/CS grafts. The percentage of new bone formed (NB%) was evaluated histomorphometrically after 6 and 12 weeks.
  
  
  RESULTS
  The N-HA group exhibited more new bone formation compared with other groups at 6 and 12 weeks. Histomorphometric analysis showed greater NB% in N-HA group (11.2% at 4 weeks and 19.2% at 12 weeks) compared with those in unfilled (3.9% at 6 weeks and 6.4% at 12 weeks), BO-treated (6.4% at 6 weeks and 8.2% at 12 weeks) and N-HA/CS-treated (6.3% at 6 weeks and 12.6% at 12 weeks) groups. The N-HA group showed significant differences in NB% compared with unfilled group at 6 weeks (P=0.016), unfilled and BO-treated groups at 12 weeks (P=0.001). The addition of CS did not enhance the NB% compared with defects grafted with N-HA alone.
  
  
  CONCLUSIONS
  N-HA was an osteoconductive bone substitute for treating osseous defects in critical size defects of rat calvaria.
authors.affiliation: Department of Periodontology, School of Dentistry, Kyungpook National University, Daegu, South Korea. jinwoo@knu.ac.kr
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Je-Hee
authors.initials: JH
authors.lastname: Jang
authors.forename: Sang-Ryul
authors.initials: SR
authors.lastname: Bae
authors.forename: Chang-Hyeon
authors.initials: CH
authors.lastname: An
authors.forename: Jo-Young
authors.initials: JY
authors.lastname: Suh
mesh_terms: D020341:Absorbable Implants; D000704:Analysis of Variance; D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000737:chemistry / Q000145:classification / Q000627:therapeutic use*; D002119:Calcium Carbonate / Q000737:chemistry / Q000627:therapeutic use; D002133:Calcium Sulfate / Q000737:chemistry / Q000627:therapeutic use; D002645:Chickens; D003399:Craniotomy / Q000379:methods; D017886:Durapatite / Q000737:chemistry / Q000627:therapeutic use*; D004528:Egg Shell / Q000737:chemistry; D008297:Male; D008903:Minerals / Q000737:chemistry / Q000627:therapeutic use; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods; D012886:Skull / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery; D018709:Statistics, Nonparametric; D014945:Wound Healing / Q000502:physiology
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D008903:Minerals; D017886:Durapatite; D002119:Calcium Carbonate; D002133:Calcium Sulfate