title: Bone neo-formation and mineral degradation of 4Bone.(®) Part I: material characterization and SEM study in critical size defects in rabbits.
abstract: OBJECTIVE
  This study reports the characterization process and in vivo application of a new high-porosity biphasic calcium phosphate (4Bone(®) - HA 60%/β-TCP 40%) inserted into the critical size defect of a rabbit tibiae.
  
  
  METHODS
  Two critical size defects of 6 mm diameter were created in each tibia of 15 New Zealand rabbits, and a total of 60 defects were divided into a test group filled with 4Bone(®) (n = 30) and a control group (n = 30). The material and the implants were characterized by scanning electron microscope (SEM) fitted with energy-dispersive X-ray spectroscopy (EDX).
  
  
  RESULTS
  The biomaterial's grain size decreased progressively with the graft integration process over the 60-day study period. Element analysis revealed increased percentages of Ca/P (2.86 ± 0.32 vs. 1.97 ± 0.59) in new bone and at the interface (P < 0.05). Element mapping showed that Ca and P were concentrated in the medullary and cortical zones in the test group but were concentrated only in cortical zones in the control group.
  
  
  CONCLUSIONS
  Critical size defects in a rabbit tibia model can be sealed using this highly porous biphasic calcium phosphate; it supports new bone formation, creates a bridge between defect borders, and facilitates bone in growth.
authors.affiliation: Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: José E
authors.initials: JE
authors.lastname: Maté Sánchez de Val
authors.affiliation: Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Calvo Guirado
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Delgado Ruiz
authors.affiliation: Faculty of Dentistry, University of Granada, Granada, Spain.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Gómez Moreno
authors.affiliation: Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Ramírez Fernández
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Georgios E
authors.initials: GE
authors.lastname: Romanos
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000008:administration & dosage* / Q000378:metabolism; D004195:Disease Models, Animal; D048091:Guided Tissue Regeneration / Q000379:methods*; D006882:Hydroxyapatites / Q000008:administration & dosage* / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000187:drug effects*; D011817:Rabbits; D013052:Spectrometry, X-Ray Emission; D013977:Tibia / Q000293:injuries* / Q000473:pathology; D016896:Treatment Outcome; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D018786:Bone Substitutes; D006882:Hydroxyapatites; C074950:hydroxyapatite-beta tricalcium phosphate
keywords: animal experiments; biomaterials; bone; guided tissue regeneration; regeneration