title: Bone tissue modelling and remodelling following guided bone regeneration in combination with biphasic calcium phosphate materials presenting different microporosity.
abstract: OBJECTIVE
  The aim of this study was to investigate bone regeneration following application of a novel biphasic calcium phosphate (BCP I) composed of microstructured granules of 90% β-tricalcium phosphate (β-TCP)/10% hydroxyapatite (HA) compared to BCP non-microstructured biphasic calcium phosphate with a composite of 60% hydroxyapatite/40% β-TCP (BCP II) and a deproteinized bovine bone mineral (DBBM) at surgically created defects in the mandible of minipigs in a combined approach with guided bone regeneration (GBR).
  
  
  METHODS
  Sixteen minipigs were used for the study. Lower premolars P2, P3, P4 and first molar M1 were extracted. Following 3 months of healing, two defects with a width and depth of 7 mm were created bilaterally in the mandible. The different grafting materials were randomly placed in the created defects and covered by means of a collagen membrane. After 3 and 8 weeks, biopsies were sampled. All specimens were evaluated with descriptive histology and histomorphometric evaluations complemented by micro-CT scan analysis.
  
  
  RESULTS
  All three biomaterials presented with higher bone volume at 8 weeks compared to 3 weeks (P < 0.0442). BCP I and DBBM demonstrated a significant higher amount of bone formation compared to BCP II at 8 weeks (P < 0.0328). BCP I also demonstrated a significant higher percentage of remaining graft volume compared to the other test groups both at 3 and 8 weeks (P < 0.0001 to P < 0.0003). Congruently, defects containing BCP I showed a significant higher amount of mineralized tissue compared to the other groups.
  
  
  CONCLUSIONS
  All the three test materials performed well with regard to bone formation at 8 weeks. BCP I showed significant higher amounts of newly formed bone despite a higher remaining graft volume compared to the other groups. With regard to the regenerative outcome, all the three materials can be recommended for clinical use.
authors.affiliation: Department of Biomaterials, Institute for Surgical Sciences, Sahgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|Department of Oral & Maxillofacial Surgery, NÄL Medical Centre Hospital, Trollhättan, Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Dahlin
authors.affiliation: Institut Straumann, Basel, Switzerland.
authors.forename: Marcel
authors.initials: M
authors.lastname: Obrecht
authors.affiliation: Department of Periodontology and Implant Dentistry, New York University, College of Dentistry, New York, NY, USA.
authors.forename: Michel
authors.initials: M
authors.lastname: Dard
authors.affiliation: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK.
authors.forename: Nikos
authors.initials: N
authors.lastname: Donos
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology*; D018786:Bone Substitutes / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D006882:Hydroxyapatites / Q000494:pharmacology*; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D008903:Minerals / Q000494:pharmacology; D010316:Particle Size; D016062:Porosity; D013524:Surgical Flaps; D013552:Swine; D013556:Swine, Miniature; D014081:Tooth Extraction; D055114:X-Ray Microtomography
chemical_list: C106416:Bio-Gide; C077540:Bio-Oss; D018786:Bone Substitutes; D006882:Hydroxyapatites; D008903:Minerals; C074950:hydroxyapatite-beta tricalcium phosphate; D003094:Collagen
keywords: GBR; alveolar socket; bone substitute; graft; guided bone regeneration; membranes