Bone regeneration after topical BMP-2-gene delivery in circumferential peri-implant bone defects.
OBJECTIVE
The aims of this study were to evaluate the rate of bone formation and osseointegration after topical gene delivery with a liposomal vector system carrying bone morphogenetic protein (BMP)-2 cDNA in combination with a collagen carrier and autologous bone as a carrier in freshly created peri-implant bone defects.


METHODS
Eight domestic pigs received nine calvariae defects each (10 x 7 mm). A dental implant was inserted into the centre of each defect. In the test groups, the remaining space was filled with the liposomal vector/BMP-2 complex combined with a collagen carrier (n=18) or an autologous bone graft (n=18). Control groups were collagen only (n=18) and autologous bone graft only (n=18).


RESULTS
There was a significant difference in mineralisation rate in the BMP-2/bone graft (29.9%+/- 4.8 and 68.3%+/- 7.2) and bone graft only (22.6%+/- 2.6 and 49.4%+/- 13.9) groups after 7 and 28 days. Mineralisation values were also significantly higher in the BMP-2/collagen group (21.2%+/- 16.2 and 53.1%+/- 12.5) compared with the collagen-only group (8.2%+/- 7 and 41%+/- 8.1) in two different regions after 28 days. Also the bone-to-implant contact was significantly increased in the BMP-2/bone graft group after 28 days and in the BMP-2/collagen group after 7 and 28 days compared with their control groups.


CONCLUSIONS
The results of this study show a significantly positive effect of liposomal vector/BMP-2 on bone regeneration and osseointegration in bony circumferential peri-implant defects.
Lutz
Rainer
R
Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany. Rainer.Lutz@uk-erlangen.de
Park
Jung
J
Felszeghy
Endre
E
Wiltfang
Jörg
J
Nkenke
Emeke
E
Schlegel
Karl Andreas
KA
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage* / Q000235:genetics; D001861:Bone Regeneration / Q000235:genetics / Q000502:physiology*; D016025:Bone Transplantation / Q000379:methods / Q000502:physiology; D003094:Collagen; D018076:DNA, Complementary; D015921:Dental Implants; D016503:Drug Delivery Systems; D005260:Female; D005624:Frontal Bone / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage; D008081:Liposomes; D016348:Osseointegration / Q000235:genetics / Q000502:physiology*; D010012:Osteogenesis / Q000235:genetics / Q000502:physiology; D010957:Plasmids / Q000008:administration & dosage; D018709:Statistics, Nonparametric; D034421:Sus scrofa; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000235:genetics; D014182:Transplantation, Autologous / Q000379:methods / Q000502:physiology
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018076:DNA, Complementary; D015921:Dental Implants; D008081:Liposomes; D016212:Transforming Growth Factor beta; D003094:Collagen