Experimental tooth movement into bone induced by recombinant human bone morphogenetic protein-2.
OBJECTIVE
The development of biomaterials for secondary bone grafting to the alveolar cleft, recombinant human morphogenetic protein-2 (rhBMP-2) may have great potential to promote osseous regeneration. The purpose of this study was to investigate the osteoinductive activity of low-dose rhBMP-2 (10 microg/100 microL) and the biological response of newly generated bone to orthodontic stimulation, compared with previous results using high-dose rhBMP-2 (40 microg/100 microL).


METHODS
After extraction of the maxillary first premolars, bone defects were surgically created in eight adult beagle dogs using a 5-mm-diameter trepan bar. The rhBMP-2 with a PLGA/gelatin sponge complex (PGS) made of gelatin and polylactic acid polyglycolic acid copolymer was immediately implanted. The osteoinductive activity of rhBMP-2 and tooth movement into the newly generated bone was evaluated based on histological and morphometric examination.


RESULTS
Dramatic histological and morphometric differences were found in the time course of bone remodeling between low- and high-dose rhBMP-2. The onset of bone remodeling occurred significantly earlier in low-dose rhBMP-2. During experimental tooth movement, in contrast to high-dose rhBMP-2, with which root resorption occurred, only partial cementum resorption occurred on the pressure side with low-dose rhBMP-2.


CONCLUSIONS
These results indicated that the proper dosage of rhBMP-2 should be determined for successful clinical application.
Kawamoto
Tatsuo
T
Maxillofacial Orthognathics, Maxillofacial Reconstruction, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. t-kawamoto.mort@tmd.ac.jp
Motohashi
Nobuyoshi
N
Kitamura
Atsushi
A
Baba
Yoshiyuki
Y
Suzuki
Shoichi
S
Kuroda
Takayuki
T
D020341:Absorbable Implants; D000539:Alveolar Process / Q000033:anatomy & histology / Q000502:physiology*; D000541:Alveolectomy; D000818:Animals; D001672:Biocompatible Materials; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology / Q000502:physiology*; D001861:Bone Regeneration / Q000502:physiology*; D016025:Bone Transplantation; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology*; D011994:Recombinant Proteins; D014087:Tooth Movement Techniques
D001672:Biocompatible Materials; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins