Evaluation of recombinant human bone morphogenetic protein-2 on the repair of alveolar ridge defects in baboons.
BACKGROUND
The objective of this study was to evaluate alveolar ridge augmentation following surgical implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) using two novel space-providing carrier technologies in the baboon (Papio anubis) model.


METHODS
Standardized alveolar ridge defects ( approximately 15 x 8 x 5 mm) were surgically produced in maxillary and mandibular edentulous areas in four baboons. The defect sites were implanted with rhBMP-2 (0.4 mg/mL) in a tricalcium phosphate/hydroxyapatite/ absorbable collagen sponge composite (TCP/HA/ACS) or calcium phosphate cement (alpha-BSM). Control treatments were TCP/HA/ACS and ?-BSM without rhBMP-2 and sham surgery. Stainless steel pins were placed at the mid-apical and coronal level of the defect sites to provide landmarks for clinical measurements pre- and post-implantation. Impressions were obtained pre- and postimplantation to determine changes in alveolar ridge volume. Radiographic registrations were obtained pre- and post-implantation. Block sections of the defect sites were harvested at week 16 postimplantation and processed for histometric analysis including new bone area and bone density. Statistical comparisons between treatments were made using a mixed effect generalized linear model using least squares estimation.


RESULTS
The carrier systems without rhBMP-2 provided a modest ridge augmentation. The addition of rhBMP-2 resulted in an almost 2-fold increase in alveolar ridge width, including a greater percentage of trabecular bone and a higher bone density compared to controls (P < or =0.05) without significant differences between the two rhBMP-2 protocols.


CONCLUSIONS
TCP/HA/ACS and alphaBSM appear to be suitable carrier technologies for rhBMP-2. Alveolar augmentation procedures using either technology combined with rhBMP-2, rather than stand-alone therapies, may provide clinically relevant augmentation of alveolar ridge defects for placement of endosseous dental implants.
Department of Periodontics, University of Illinois at Chicago, College of Dentistry, Chicago, IL, USA.
Dario A O
DA
Miranda
Neil M
NM
Blumenthal
Rachel G
RG
Sorensen
John M
JM
Wozney
Ulf M E
UM
Wikesjö
D020341:Absorbable Implants; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D001861:Bone Regeneration / Q000187:drug effects*; D002130:Calcium Phosphates; D003094:Collagen; D004337:Drug Carriers; D017886:Durapatite; D006801:Humans; D016018:Least-Squares Analysis; D048530:Papio anubis; D011897:Random Allocation; D011994:Recombinant Proteins / Q000008:administration & dosage; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D002130:Calcium Phosphates; D004337:Drug Carriers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen; D017886:Durapatite; C020243:calcium phosphate; C018392:tricalcium phosphate