The effect of combination of recombinant human bone morphogenetic protein-2 and basic fibroblast growth factor or insulin-like growth factor-I on dental implant osseointegration by confocal laser scanning microscopy.
BACKGROUND
The healing period of bone-implant osseointegration usually varies from 3 to 6 months or even longer. Failure may occur during this time. This study aimed to investigate whether osseointegration of dental implants can be enhanced by the combination of growth factors.


METHODS
Sixty-four implants were coated with polylactic acid and divided into four groups. Group I was applied with 1.0 mg recombinant human bone morphogenetic protein-2 (rhBMP-2) and 200 microg recombinant human basic fibroblast growth factor (rhbFGF), group II with 1.0 mg rhBMP-2 and 250 mug recombinant human insulin-like growth factor-I (rhIGF-I), group III with 1.0 mg rhBMP-2, and group IV without growth factors as control. In total, 16 rabbits were used, and two osteotomies were drilled on each side of the femur, in which four different groups were randomly placed. Four weeks after implanting, 20 mg calcein green/kg body weight was administered intravenously, and 8 weeks after implanting, 20 mg alizarin/kg body weight was administered intravenously. Twelve weeks after implanting, the animals were sacrificed. The block of bone with implants was embedded in methylmethacrylate and sectioned, and the percentage of new bone surrounding the implant was analyzed by confocal laser scanning microscopy.


RESULTS
There was a statistical difference in bone formation between rhBMP-2-applied groups and the non-applied group at 4 or 8 weeks, and no significant difference between groups I and II (although bone formation in group II was greater than that in group I at 4 weeks). The bone formation in group II was greater than that in group III at 4 or 8 weeks. The formed bone in group I was also greater than the one in group III at 8 weeks, but there was no difference at 4 weeks.


CONCLUSIONS
rhBMP-2 could increase new bone formation, and it acted synergistically with rhbFGF and rhIGF-I to improve bone-implant osseointegration. The combination of rhBMP-2 and rhbFGF (group 1) showed faster growth of new bone than other groups at 8 months.
Lan
Jing
J
Department of Prosthodontics, School of Stomatology, Key Lab for Oral Biomedical Engineering of Ministry of Education, Wuhan University, Wuhan, China.
Wang
Zhifeng
Z
Wang
Yining
Y
Wang
Jiawei
J
Cheng
Xiangrong
X
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D004338:Drug Combinations; D004357:Drug Synergism; D005269:Femur; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006801:Humans; D020007:Implants, Experimental; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D019344:Lactic Acid; D008297:Male; D018613:Microscopy, Confocal; D016348:Osseointegration / Q000187:drug effects*; D011091:Polyesters; D011108:Polymers; D011817:Rabbits; D011994:Recombinant Proteins; D018709:Statistics, Nonparametric; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D004338:Drug Combinations; D011091:Polyesters; D011108:Polymers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D019344:Lactic Acid; C033616:poly(lactide); D007334:Insulin-Like Growth Factor I