title: Liquid nitrogen-treated autogenous dentin as bone substitute: an experimental study in a rabbit model.
abstract: OBJECTIVE
  Different forms of dentin, including untreated, undemineralized, demineralized, boiled, or mixed with other materials, have been evaluated for efficacy as bone substitutes. However, the effects of application of liquid nitrogen-treated dentin for bone grafting remain unknown. The objective of this study was to chronologically evaluate bone healing following grafting with liquid nitrogen-treated dentin in a rabbit model.
  
  
  METHODS
  Autogenous dentin treated with liquid nitrogen at -196°C for 20 minutes was used. In 16 New Zealand White rabbits, a bone defect (5 mm in diameter) was created in each femur and randomly grafted with either autogenous dentin (experimental group) or autogenous bone grafts (positive control). In another four rabbits (negative control), a similar defect in each femur was left empty. The rabbits were sacrificed at 2, 4, 8, and 12 weeks. Explants of grafted sites were harvested for histologic and histomorphometric analysis.
  
  
  RESULTS
  At 2 and 4 weeks in both the experimental and positive control groups, accelerated formation of new bone was observed, which was undergoing remodeling at 8 and 12 weeks. The mean new bone score was higher in the experimental than in the negative control groups, but this was not statistically significant.
  
  
  CONCLUSIONS
  The present results demonstrated that liquid nitrogen-treated autogenous dentin has both osteoconductive and osteoinductive properties and therefore has potential as a bone substitute.
authors.forename: Basim K
authors.initials: BK
authors.lastname: Atiya
authors.forename: Palasuntharam
authors.initials: P
authors.lastname: Shanmuhasuntharam
authors.forename: Siar
authors.initials: S
authors.lastname: Huat
authors.forename: Shurooq
authors.initials: S
authors.lastname: Abdulrazzak
authors.forename: Ha
authors.initials: H
authors.lastname: Oon
mesh_terms: D000818:Animals; D018786:Bone Substitutes; D016025:Bone Transplantation / Q000379:methods; D015925:Cryopreservation; D003804:Dentin / Q000637:transplantation*; D004195:Disease Models, Animal; D009584:Nitrogen; D011817:Rabbits; D014182:Transplantation, Autologous
chemical_list: D018786:Bone Substitutes; D009584:Nitrogen