Efficacy of titanium implants of different surfaces as BMP-carriers - An animal study at the orthotopic implant bed of giant rabbits

Background/Aim of the Study: The successful combination of osteoinductive f actors with prosthetic implants may have therapeutic applications to improv e their bony ingrowth and long term stability. We examined the suitability of metal implants of different surfaces and structures as carriers of BMP-3 and how the osteogenic activity of such composite implants is influenced b y the chemical composition and structure of the implant surface. Methods: In this study in 30 adult giant rabbits the ability of BMP-3 in co mbination with Ti alloy implants (Ti-6A1-4V) of different surfaces and stru ctures (hydroxyapatite-coated or corundum-blasted) used in endoprosthetic a nd dental implantology was tested to optimize osteoinductivity and to accel erate bony ingrowth of the implants in the femoral condyles of the animals. Results: Coating with BMP-3 led in both groups with different implant surfa ces after press-fit-implantation to a histologically and histomorphometrica lly detectable better osseointegration of the implants compared to the non- coated implants of the same type. Statistic evaluation using the T-Test for matched samples showed 5 weeks after implantation a significant higher vol ume of new formed bone for BMP-3-coated corundum-blasted or hydroxyapatite- coated Ti-6A1-4V implants compared to the refering non-coated controls (p < 0,01). Better osseointegration was achieved in the hydroxyapatite-coated i mplants than in the corundum-blasted implants. Conclusion: Our findings indicate that composite metal implants used in end oprosthetic and dental implantology are suitable carriers of BMP-3 and that the induced process of new bone formation is also influenced by the chemic al composition and the structure of the implant surface.