rhBMP-2 significantly enhances guided bone regeneration.
BACKGROUND
Previous studies have shown a limited potential for bone augmentation following guided bone regeneration (GBR) in horizontal alveolar defects. Surgical implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge carrier (ACS) significantly enhances bone regeneration in such defects; however, sufficient quantities of bone for implant dentistry are not routinely obtained. The objective of this study was to evaluate the potential of rhBMP-2/ACS to enhance GBR using a space-providing, macro-porous expanded polytetrafluoroethylene (ePTFE) device.


METHODS
Bilateral, critical size, supra-alveolar, peri-implant defects were surgically created in four Hound Labrador mongrel dogs. Two turned and one surface-etched 10-mm titanium dental implant were placed 5 mm into the surgically reduced alveolar ridge creating 5-mm supra-alveolar defects. rhBMP-2/ACS (rhBMP-2 at 0.2 mg/ml) or buffer/ACS was randomly assigned to left and right jaw quadrants in subsequent animals. The space-providing, macro-porous ePTFE device was placed to cover rhBMP-2/ACS and control constructs and dental implants. Gingival flaps were advanced for primary wound closure. The animals were euthanized at 8 weeks postsurgery for histologic and histometric analysis.


RESULTS
Bone formation was significantly enhanced in defects receiving rhBMP-2/ACS compared to control. Vertical bone gain averaged (+/- SD) 4.7 +/- 0.3 and 4.8 +/- 0.1 mm, and new bone area 10.3 +/- 2.0 and 8.0 +/- 2.5 mm2 at turned and surface-etched dental implants, respectively. Corresponding values for the control were 1.8 +/- 2.0 and 1.3 +/- 1.3 mm, and 1.8 +/- 1.3 and 1.2 +/- 0.6 mm2. Bone-implant contact in rhBMP-2-induced bone averaged 6.4 +/- 1.4% and 9.6 +/- 7.5% for turned and surface-etched dental implants, respectively (P=0.399). Corresponding values for the control were 14.6 +/- 19.4% and 23.7 +/- 9.7% (P=0.473). Bone-implant contact in resident bone ranged between 43% and 58% without significant differences between dental implant surfaces.


CONCLUSIONS
rhBMP-2/ACS significantly enhances GBR at turned and surface-etched dental implants. The dental implant surface technology does not appear to substantially influence bone formation.
Wikesjö
Ulf M E
UM
Laboratory for Applied Periodontal and Craniofacial Regeneration, Department of Periodontology, Temple University School of Dentistry, Philadelphia, PA 19140, USA. ulf.wikesjo@temple.edu
Qahash
Mohammed
M
Thomson
Robert C
RC
Cook
Alonzo D
AD
Rohrer
Michael D
MD
Wozney
John M
JM
Hardwick
W Ross
WR
D020341:Absorbable Implants; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D003094:Collagen; D003758:Dental Implantation, Endosseous / Q000009:adverse effects; D015921:Dental Implants / Q000009:adverse effects; D004285:Dogs; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D016348:Osseointegration; D010518:Periodontitis / Q000209:etiology; D011138:Polytetrafluoroethylene; D011859:Radiography; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D016212:Transforming Growth Factor beta
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D015921:Dental Implants; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D011138:Polytetrafluoroethylene; D003094:Collagen