Mechanical evaluation of TiO_2-gritblasted and Ca-P magnetron sputter coated implants in goats

摘要

Our aim was to evaluate the mechanical bone anchorage of TiO_2-gritblasted titanium implants as received (Ti) or provided with a calciumphosphate (Ca-P) coating of 0.1 mu m (CaP-0.1), 1 mu m (CaP-1), or 4 mu m (CaP-4) thickness. The implants were inserted in the femoral condyle of 12 goats. After 6 and 12 weeks, interface strength and appearance was evaluated using torque testing and scanning electron microscopy (SEM). Alreday at 6 weeks, all implants resisted very high torsional failure forces (Ti=117 Nm, CaP-0.1=142 Nm, CaP-1=154 Nm, and CaP-4=150 Nm). Although, CaP coated implants showed higher torque failure loads than noncoated implants, no statistical difference existed. The 12 week data (Ti=154 Nm, CaP-0.1=159 Nm, CaP-1=140 Nm, and CaP-4=171 Nm) demonstrated again no significant differences. Nevertheless, SEM showed that CaP-coated implants conducted more bone growth into the screwthreads. The fracture plane for CaP-4 implants was situated at the coating-implant interface or inside the coating. For CaP-0.1, CaP-1, and Ti implants, torque testing tesulted in failure at the bone-implant interface. Therefore, we conclude that all implants dresulted in a good bone bonding strength. The Ca-P coatings showed no negative initial effect, but seemed to improve the bone fixation.