2017 Volume 58 Issue 1 Pages 113-117
When titanium (Ti) alloys are used for bone fixators after bone fracture, Ti alloys form new bone around themselves in human bone. This ability can cause re-fracture when the fixators are retrieved after bone healing. Surface treatments that do not cause bone formation around Ti alloy are necessary. The purpose of this study was to clarify the inhibitory effect of zirconium (Zr) coating on bone bonding of Ti alloy in rat femur. Non-coated and Zr-coated Ti implants were inserted into the medullary canal of the right and left femur (randomized to side). Four weeks later, the femurs with the implants were removed. The shear strength of implant fixation with the bone was measured by a pull-out test. The amount of the residual new bone adhered on the implants after the pull-out test was evaluated. Pull-out shear strength and the amount of bone elements around implant were lower in Zr-coated group than in non-coated group. Our study indicates that Zr coating inhibits bone bonding between Ti implant and bone in vivo. This technique may be useful to prevent re-fracture when Ti implants are removed from human bone after bone healing.