Expression of bone morphogenetic protein 2 and fibroblast growth factor 2 during bone regeneration using different implant materials as an onlay bone graft in rabbit mandibles.
OBJECTIVE
The purpose of this study was to histologically and immunohistochemically evaluate bone regeneration using 3 different implant materials in rabbit mandibles and to compare the bone regenerative capability of these materials in an animal model.


METHODS
Adult male Japanese white rabbits (n = 48; 12-16 wks old; 2.5-3.0 kg) were divided into 4 groups, consisting of 12 animals each. The implant materials were beta-tricalcium phosphate (beta-TCP), autologous bone derived from the radius, and recombinant human bone morphogenetic protein 2 (rhBMP-2) with polylactic acid/polyglycolic acid copolymer and gelatin sponge (PGS) complex. After incising along the inferior border of the mandible, the materials were implanted as only grafts and covered by titanium mesh with screws. No material was implanted into the control group. The rabbits were killed at 2, 4, 8, 12, and 24 wks postoperatively, and formalin-fixed specimens containing titanium mesh were embedded in acrylic resin. The specimens were stained with hematoxylin and eosin. For immunohistochemical analysis, the specimens were treated with BMP-2 and fibroblast growth factor 2 (FGF-2) antibodies. Finally, they were examined microscopically.


RESULTS
The autologous bone induced substantially more new bone formation compared with beta-TCP at 4 wks postoperatively. However, rhBMP-2/PGS induced new bone formation at 8 wks postoperatively. No growth of bony tissue was observed in the control group at any period. In the autologous bone and rhBMP-2/PGS groups, both BMP-2 and FGF-2 were observed later in the beta-TCP group than in other groups.


CONCLUSIONS
This study suggests that autologous bone as well as rhBMP-2/PGS implants induce expression of both BMP-2 and FGF-2 specifically at the operated sites, even at early stages.
Alam
Shamiul
S
Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa and Toyama, Japan.
Ueki
Koichiro
K
Marukawa
Kohei
K
Ohara
Teruhisa
T
Hase
Takashi
T
Takazakura
Daisuke
D
Nakagawa
Kiyomasa
K
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000378:metabolism* / Q000627:therapeutic use*; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods; D002130:Calcium Phosphates / Q000627:therapeutic use*; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D019344:Lactic Acid / Q000627:therapeutic use; D008297:Male; D008334:Mandible / Q000378:metabolism / Q000601:surgery; D023421:Models, Animal; D011091:Polyesters; D011108:Polymers / Q000627:therapeutic use; D011817:Rabbits; D011884:Radius / Q000637:transplantation; D011994:Recombinant Proteins / Q000627:therapeutic use*; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000627:therapeutic use*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011091:Polyesters; D011108:Polymers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C485817:beta-tricalcium phosphate; C499469:recombinant human bone morphogenetic protein-2; D016222:Fibroblast Growth Factor 2; D019344:Lactic Acid; C033616:poly(lactide)