Scaffold-based rhBMP-2 therapy in a rat alveolar defect model: implications for human gingivoperiosteoplasty

Plast Reconstr Surg. 2009 Dec;124(6):1829-1839. doi: 10.1097/PRS.0b013e3181bf8024.

Abstract

Background: Primary alveolar cleft repair has a 41 to 73 percent success rate. Patients with persistent alveolar defects require secondary bone grafting. The authors investigated scaffold-based therapies designed to augment the success of alveolar repair.

Methods: Critical-size, 7 x 4 x 3-mm alveolar defects were created surgically in 60 Sprague-Dawley rats. Four scaffold treatment arms were tested: absorbable collagen sponge, absorbable collagen sponge plus recombinant human bone morphogenetic protein-2 (rhBMP-2), hydroxyapatite-tricalcium phosphate, hydroxyapatite-tricalcium phosphate plus rhBMP-2, and no scaffold. New bone formation was assessed radiomorphometrically and histomorphometrically at 4, 8, and 12 weeks.

Results: Radiomorphometrically, untreated animals formed 43 +/- 6 percent, 53 +/- 8 percent, and 48 +/- 3 percent new bone at 4, 8, and 12 weeks, respectively. Animals treated with absorbable collagen sponge formed 50 +/- 6 percent, 79 +/- 9 percent, and 69 +/- 7 percent new bone, respectively. Absorbable collagen sponge plus rhBMP-2-treated animals formed 49 +/- 2 percent, 71 +/- 6 percent, and 66 +/- 7 percent new bone, respectively. Hydroxyapatite-tricalcium phosphate treatment stimulated 69 +/- 12 percent, 86 +/- 3 percent (p < 0.05), and 87 +/- 14 percent new bone, respectively. Histomorphometry demonstrated an increase in bone formation in animals treated with hydroxyapatite-tricalcium phosphate plus rhBMP-2 (p < 0.05; 4 weeks) compared with empty scaffold.

Conclusions: Radiomorphometrically, absorbable collagen sponge and hydroxyapatite-tricalcium phosphate scaffolds induced more bone formation than untreated controls. The rhBMP-2 added a small but significant histomorphometric osteogenic advantage to the hydroxyapatite-tricalcium phosphate scaffold.

Publication types

  • Comparative Study

MeSH terms

  • Absorbable Implants
  • Alveolar Ridge Augmentation / methods*
  • Animals
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins / pharmacology*
  • Bone Regeneration / drug effects
  • Bone Regeneration / physiology
  • Calcium Phosphates / pharmacology*
  • Cleft Palate / surgery
  • Disease Models, Animal
  • Female
  • Gingivoplasty / methods
  • Humans
  • Male
  • Oral Surgical Procedures / methods
  • Osteogenesis / drug effects*
  • Osteogenesis / physiology
  • Periosteum / surgery
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley
  • Recombinant Proteins / pharmacology*
  • Reconstructive Surgical Procedures / methods*
  • Risk Factors
  • Transforming Growth Factor beta / pharmacology*

Substances

  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins
  • Calcium Phosphates
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • recombinant human bone morphogenetic protein-2
  • tricalcium phosphate