ECTOPIC BONE-FORMATION BY COMPOSITES OF BMP AND METAL IMPLANTS IN RATS

Disc-shaped implants of titanium alloy (Ti-6Al-4V) were treated on one side by corundum-blasting (CB) or by coating with hydroxyapatite (HA) or pure titanium (Ti) using plasma spraying, Half of the implants wer e additionally coated with purified swine BMP-3. The composites and th e uncoated controls were implanted into abdominal wall-muscle pouches of rats, 25 days after implantation, ectopic bone formation could be o bserved macroscopically and histologically in a high frequency in all 3 groups of BMP-coated implants, whereas the controls were constantly inactive, The volumes of induced bone were similar for BMP-3-coated pu re Ti and HA implants, while CB implants were significantly less activ e, Our findings indicate that the bone formation process is influenced by the chemical composition and by the structure of the implant surfa ce.