A low‐temperature biomimetic calcium phosphate surface enhances early implant fixation in a rat model

Abstract

The present study demonstrates increased early mechanical fixation of titanium implants coated with a new biomimetic apatite surface in a rat model. Male Sprague-Dawley rats received unilateral femoral medullary implants for periods of 1–4 weeks. The strength of fixation of the implant to the host bone increased more rapidly in the group receiving apatite-treated implants compared with the control group as evidenced by the apatite group's 21-fold greater fixation strength at 1 week (p = 0.009), 4-fold greater fixation strength at 2 weeks (p = 0.041), and 2-fold greater fixation strength at 4 weeks (p = 0.093) compared with the control. Fixation strength was correlated with bone–implant contact as determined from micro computed tomography assessment of the specimens (r² = 0.338, p = 0.011 in the control group and r² = 0.543, p < 0.001 in the apatite group). Furthermore, for a given amount of bone–implant contact, the fixation strength was higher in the apatite group than in the control group (p = 0.011), suggesting that the bone formed a stronger bond to the apatite coating than to the titanium. This difference in bonding strength accounted for the difference in mechanical behavior. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 66–73, 2004