title: Histomorphometric evaluation of bone regeneration using allogeneic and alloplastic bone substitutes.
abstract: OBJECTIVE
  The purpose of this investigation was to assess bone regeneration in critical sized defects in the rabbit calvarium using allogeneic and alloplastic bone substitutes.
  
  
  METHODS
  Thirty New Zealand White rabbits were divided into 3 groups of 10 animals each. Bilateral 15 mm x 17 mm calvarial defects were made in the parietal bones of each animal. Group 1 had demineralized bone matrix (DBM) gel placed in one defect, while the other defect was left unfilled and served as the control. Group 2 had one defect filled with calcium hydroxide (CaOH)-treated DBM gel and the other defect filled with DBM gel. Group 3, the calcium-phosphate cement group, had Norian CRS (Norian Corp, Cupertino, CA) placed on one side and Bone Source (Howmedica Leibinger, Dallas, TX) placed on the contralateral side. Five animals in each group were killed at 6 and 12 weeks. Data analysis included qualitative assessment of the calvarial specimens and radiographic evaluation. Histomorphometric analysis was used to quantify the amount of new bone within the defects.
  
  
  RESULTS
  Histomorphometric analysis showed that DBM gel-treated defects had significantly more new bone at 12 weeks compared with all other groups. There was no significant difference between defects filled with CaOH-treated DBM gel and those filled with DBM gel at 12 weeks. In group 3, Norian CRS- and Bone Source-treated defects were not statistically different from the unfilled controls.
  
  
  CONCLUSIONS
  DBM gel was an effective allogeneic bone substitute that showed reliable osseous healing of critical size defects in the rabbit calvarium. The addition of CaOH to DBM gel did not significantly improve the bone regenerative capacity of the DBM gel. Both Norian CRS and Bone Source did not promote bone regeneration in this animal model.
authors.affiliation: Department of Oral and Maxilofacial Surgery, Unviersity of Toronto, Toronto, Canada. hmoghadam@rogers.com
authors.forename: Hassan G
authors.initials: HG
authors.lastname: Moghadam
authors.forename: George K B
authors.initials: GK
authors.lastname: Sándor
authors.forename: Howard H I
authors.initials: HH
authors.lastname: Holmes
authors.forename: Cameron M L
authors.initials: CM
authors.lastname: Clokie
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000627:therapeutic use*; D001857:Bone Matrix / Q000033:anatomy & histology / Q000637:transplantation*; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000627:therapeutic use*; D002126:Calcium Hydroxide / Q000627:therapeutic use; D002130:Calcium Phosphates / Q000627:therapeutic use*; D005782:Gels / Q000627:therapeutic use; D008297:Male; D010294:Parietal Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D011817:Rabbits; D011859:Radiography; D012886:Skull / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D014945:Wound Healing / Q000502:physiology
chemical_list: D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D005782:Gels; D002126:Calcium Hydroxide