title: Hyaluronan supports recombinant human bone morphogenetic protein-2 induced bone reconstruction of advanced alveolar ridge defects in dogs. A pilot study.
abstract: BACKGROUND
  Prosthetic-driven implant dentistry requires predictable procedures for alveolar ridge augmentation. The objective of this pilot study was to evaluate bone regeneration in mandibular, full-thickness, alveolar ridge, saddle-type defects following surgical implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a novel hyaluronan (HY) sponge carrier. This sponge was fabricated from auto-crosslinked HY.
  
  
  METHODS
  Alveolar ridge defects (approximately 15 x 10 x 10 mm), 2 per jaw quadrant, were surgically prepared in each of 3 young adult American fox hounds. Four defects were immediately implanted with rhBMP-2/HY. Three defects were implanted with rhBMP-2 in an absorbable collagen sponge (ACS) carrier (positive control). The rhBMP-2 solution (1.5 ml at 0.2 mg/ml) was soak-loaded onto the HY and ACS sponges. Three defects were implanted with HY sponges soak-loaded with buffer without rhBMP-2 (negative control), while 2 defects served as surgical controls. The animals were euthanized at 12 weeks postsurgery for histometric analysis.
  
  
  RESULTS
  Clinically, alveolar ridge defects receiving rhBMP-2/ACS exhibited a slight supracrestal expansion, while defects receiving rhBMP-2/HY were filled to contour. In contrast, the HY and surgical controls exhibited ridge collapse. rhBMP-2/HY-treated defects exhibited a dense bone quality without radiolucent regions observed in defects treated with rhBMP-2/ACS. The histometric analysis showed 100% bone fill for the rhBMP-2/ACS defects and 94%, 58%, and 65% bone fill for the rhBMP-2/HY, HY, and surgical control defects, respectively.
  
  
  CONCLUSIONS
  The conclusions are based on data from 2 of 3 animals in the study. In one animal, no response to rhBMP-2 was observed with either carrier, and the animal may have been a non-responder of unknown nature. With this limitation, the observations herein suggest that: 1) HY supports significant bone induction by rhBMP-2; 2) the rhBMP-2-induced bone assumes qualities of the immediate resident bone; 3) HY alone exhibits no apparent osteoconductive potential; and 4) HY appears to resorb within a 12-week healing interval in the absence or presence of rhBMP-2. Thus, HY appears to be a suitable candidate carrier for rhBMP-2.
authors.affiliation: Division of Oral Biology & Medicine, School of Dentistry, University of California, Los Angeles 90095, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Hunt
authors.forename: S A
authors.initials: SA
authors.lastname: Jovanovic
authors.forename: U M
authors.initials: UM
authors.lastname: Wikesjö
authors.forename: J M
authors.initials: JM
authors.lastname: Wozney
authors.forename: G W
authors.initials: GW
authors.lastname: Bernard
mesh_terms: D020341:Absorbable Implants; D016301:Alveolar Bone Loss / Q000188:drug therapy* / Q000601:surgery; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology; D000540:Alveolar Ridge Augmentation; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D003094:Collagen / Q000737:chemistry / Q000627:therapeutic use; D004285:Dogs; D004337:Drug Carriers; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry / Q000627:therapeutic use*; D010012:Osteogenesis / Q000187:drug effects; D010865:Pilot Projects; D011859:Radiography; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D004337:Drug Carriers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D006820:Hyaluronic Acid; D003094:Collagen