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.
Laboratory for Applied Periodontal and Craniofacial Regeneration, Department of Periodontology, Temple University School of Dentistry, Philadelphia, PA 19140, USA. ulf.wikesjo@temple.edu
Ulf M E
UM
Wikesjö
Mohammed
M
Qahash
Robert C
RC
Thomson
Alonzo D
AD
Cook
Michael D
MD
Rohrer
John M
JM
Wozney
W Ross
WR
Hardwick
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