title: Use of a perforated scaffold-retaining abutment to achieve vertical bone regeneration around dental implants in the minipig.
abstract: OBJECTIVE
  To evaluate the effect of perforated scaffold retainers used in conjunction with dental implants and osteoinductive scaffolds to regenerate vertical supracrestal alveolar bone in an intraoral minipig model.
  
  
  METHODS
  Three months after extraction of mandibular premolars and first molars from six adult minipigs, two titanium (Ti) custom implants were placed bilaterally in the edentulous mandibles for a total of four implants per animal. The upper 2.5 mm of the implant was left above bone level and covered with: (1) wide-neck healing caps; (2) perforated, overhanging custom scaffold retainers (umbrellas); or (3) scaffold retainers and demineralized minipig bone allograft (DBM) and nonglycosylated bone morphogenetic protein 2 (ng/rhBMP-2)-treated implants. All constructs were submerged beneath soft tissue flaps for 8 weeks. Two dental implant surfaces were compared: SLA and SLActive. Samples were retrieved after 8 weeks and analyzed by radiography, micro-computed tomography and histomorphometry.
  
  
  RESULTS
  All implants were stable at the end of the experiment. Histomorphometry revealed that the use of the scaffold-retaining umbrellas led to increased, but not statistically significant, vertical bone regeneration as compared to the use of wide-neck healing caps (1.0 ± 0.4 mm vs 0.6 ± 0.3 mm). The combination of DBM and ng/rhBMP-2 released from the surface of the SLA implant resulted in the greatest amount of vertical bone regeneration (2.1 ± 0.2 mm). The bone-to-implant contact was similar for all groups. Mucosal dehiscence areas with healing cap or custom scaffold retainer exposures were reduced in the presence of ng/rhBMP-2.
  
  
  CONCLUSIONS
  The combined use of custom perforated Ti scaffold retainers, DBM, and ng/rhBMP-2 regenerated a substantial amount of vertical supracrestal alveolar bone around Ti implants in an intraoral minipig model.
authors.affiliation: Dental School, Bordeaux Segalen University and Inserm, University Bordeaux Sagalen, Tissue Bioengineering, Bordeaux, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Catros
authors.forename: Bo
authors.initials: B
authors.lastname: Wen
authors.forename: Peter
authors.initials: P
authors.lastname: Schleier
authors.forename: David
authors.initials: D
authors.lastname: Shafer
authors.forename: Michel
authors.initials: M
authors.lastname: Dard
authors.forename: Marcel
authors.initials: M
authors.lastname: Obrecht
authors.forename: Martin
authors.initials: M
authors.lastname: Freilich
authors.forename: Liisa
authors.initials: L
authors.lastname: Kuhn
mesh_terms: D000539:Alveolar Process / Q000502:physiology*; D000818:Animals; D001641:Bicuspid / Q000601:surgery; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology*; D016025:Bone Transplantation / Q000379:methods; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D006801:Humans; D007576:Jaw, Edentulous, Partially; D008334:Mandible / Q000601:surgery; D023421:Models, Animal; D018704:Orthodontic Retainers; D016348:Osseointegration / Q000502:physiology*; D011994:Recombinant Proteins / Q000008:administration & dosage; D013552:Swine; D013556:Swine, Miniature; D054457:Tissue Scaffolds; D014025:Titanium; D014081:Tooth Extraction; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D055396:Bone Morphogenetic Protein 2; D015921:Dental Implants; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D014025:Titanium