Comparison of Bone Mineral Density and Area of Newly Formed Bone Around Ti-15%Zr-4%Nb-4%Ta Alloy and Ti-6%Al-4%V Alloy Implants

Abstract
A newly developed titanium alloy, Ti-15%Zr-4%Nb-4%Ta (Ti15Zr4Nb4Ta), has been shown to have excellent mechanical characteristics, corrosion fatigue strength, anticorrosion, cytocompatibility, and biocompatibility. The purpose of this study was to compare the bone mineral density (BMD) and area of newly formed bone around Ti15Zr4Nb4Ta implants to that around Ti-6%Al-4%V alloy (Ti6Al4V) implants. We inserted 2 types of implants (surface treat of the machine and the blast implant) in New Zealand white rabbit femurs under general anesthesia. The rabbit was done perfusion fixation of 4, 8, 16, 24, and 48 weeks later, and the femurs with the implants were collected and we observed the surrounding bone by an implant drawing test. We measured the BMD and the area of the newly formed bone surrounding the implant inserted part using image analysis software Image-Pro PLUS Ver. 4.0® which it developed newly in micro focus computed tomography (micro CT). The results showed the machine and the blast implant together, which the BMD and area around the Ti15Zr4Nb4Ta implants were comparable to or greater than those around the Ti6Al4V implants. These results suggested that the new alloy, Ti15Zr4Nb4Ta, might be useful for orthopedic or dental implants with the added advantage of superior biologic safety and mechanical properties than the current alloy, Ti6Al4V.