Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-2: radiographic observations.
OBJECTIVE
Effective carrier technologies and dosing appear critical for the successful use of bone morphogenetic proteins (BMPs). This study evaluated radiographically the potential of a purpose-designed titanium porous-oxide implant surface combined with recombinant human BMP-2 (rhBMP-2) to stimulate alveolar ridge augmentation.


METHODS
Twelve young-adult Labrador dogs were used. Three 10-mm titanium implants per jaw quadrant were placed 5 mm into the alveolar ridge following extraction of the premolar teeth and reduction of alveolar ridge. Six animals received implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml randomized to contralateral jaw quadrants. Another six animals received implants coated with rhBMP-2 at 3 mg/ml or uncoated control using the same split-mouth design. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants. Radiographic registrations were made immediately postsurgery (baseline), and at weeks 4 and 8 (end of study).


RESULTS
rhBMP-2-coated implants exhibited robust radiographic bone formation extending to and above the implant platform from week 4 (P<0.01). Some rhBMP-2-coated implants showed voids within the newly formed bone that gradually resolved and/or implant displacement, being severe in two animals receiving implants coated with rhBMP-2 at 3 mg/ml. Controls showed limited, if any, new bone formation at weeks 4 and 8 postsurgery. There were no significant differences among the rhBMP-2 groups in bone gain.


CONCLUSIONS
The titanium porous-oxide surface serves as an effective carrier for rhBMP-2, showing a clinically significant potential to stimulate local bone formation. With the carrier technology used, therapeutic dosage appears to be in the range of 0.75-1.5 mg/ml.
Leknes
Knut N
KN
Department of Oral Science, Faculty of Dentistry, University of Bergen, Bergen, Norway. knut.leknes@odont.uib.no
Yang
Jie
J
Qahash
Mohammed
M
Polimeni
Giuseppe
G
Susin
Cristiano
C
Wikesjö
Ulf M E
UM
D000539:Alveolar Process / Q000000981:diagnostic imaging* / Q000187:drug effects; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000541:Alveolectomy; D000818:Animals; D001641:Bicuspid / Q000601:surgery; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage / Q000627:therapeutic use*; D001862:Bone Resorption / Q000000981:diagnostic imaging; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D004337:Drug Carriers; D006801:Humans; D008297:Male; D010012:Osteogenesis / Q000187:drug effects; D011859:Radiography; D011897:Random Allocation; D011994:Recombinant Proteins; D049291:Seroma / Q000000981:diagnostic imaging; D013499:Surface Properties; D013524:Surgical Flaps; D013997:Time Factors; D014025:Titanium; D014081:Tooth Extraction
C525718:BMP2 protein, human; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D015921:Dental Implants; D004337:Drug Carriers; D011994:Recombinant Proteins; C009495:titanium dioxide; D014025:Titanium