Characterization and In Vivo Evaluation of Trace Element-Loaded Implant Surfaces in Ovariectomized Rats.

PURPOSE The purpose of this work was to investigate the effect of a hydroxyapatite (HA) coating doped with zinc (Zn), magnesium (Mg), or strontium (Sr) on implant osseointegration in ovariectomized rats. MATERIALS AND METHODS The HA coating doped with trace elements was produced by electrochemical deposition. Surface properties were tested by field emission scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and measurement of ionic release. A total of 36 ovariectomized rats were randomly divided into four groups: the HA coating group, the Zn-HA coating group, the Mg-HA coating group, and the Sr-HA coating group. The corresponding implants were then inserted into the tibiae. Histomorphometric analysis was performed after 4, 8, and 12 weeks. RESULTS HA coatings doped with 2.5% Zn, Mg, or Sr by electrochemical deposition showed almost identical surface morphologies. Bone-implant contact (BIC) in the Zn-HA group was significantly greater than that in the HA group for all time periods. BIC values in the Sr-HA group significantly exceeded those in the HA group at 8 and 12 weeks after implantation. Bone ingrowth area values of both the Zn-HA and Sr-HA groups were statistically significantly different from those in the HA group after 8 and 12 weeks. CONCLUSION The Zn-HA and Sr-HA coatings have the potential to improve implant osseointegration in osteoporosis.