EFFECT OF ELECTROCHEMICALLY DEPOSITED APATITE COATING ON BONDING OF BONE TO THE HA-G-TI COMPOSITE AND TITANIUM

The surfaces of hydroxyapatite-glass-titanium (HA-G-Ti) functionally g radient composite and titanium bars were treated with electrochemical apatite deposition, and a cathodic current was applied at 62 degrees C in a solution containing calcium and phosphate ions. Specimens with a nd without the electrochemical surface treatment were implanted in the femurs of Japanese white rabbits. The rabbits were sacrificed at 3, 6 , and 9 weeks after implantation, and the bonding strengths of bone to these specimens were determined by a pull-out method. At 3 and 6 week s after implantation the specimens with the electrochemical surface tr eatment showed larger values for the Weibull modulus and characteristi c strengths than those of untreated specimens, whereas there was no re markable difference in the results at 9 weeks. Especially the pull-out strengths of surface-treated specimens were significantly larger than the untreated ones at 3 weeks after implantation. Scanning electron m icroscopy and Fourier transform infrared absorption spectroscopy of th e specimen surface after implantation demonstrated that formation of n ew bone was enhanced by the electrochemical surface treatment. It can be concluded that the electrochemical surface treatment undoubtedly co ntributes to the early stage fixation between bone and implant. (C) 19 97 John Wiley & Sons.