Strontium‐incorporated titanium implant surface treated by hydrothermal reactions promotes early bone osseointegration in osteoporotic rabbits

Abstract

OBJECTIVES: The aim of the present study was to investigate the effects of strontium-modified implant surfaces on promoting early bone osseointegration in osteoporotic rabbits. MATERIALS AND METHODS: The surface topographies, chemical elements, contact angles and ionic releases of the SLA and SLA-Sr samples were analysed by special instruments separately. Sixteen ovariectomized New Zealand rabbits received glucocorticoid administration, and sixteen SHAM rabbits were used as controls. After generating a successful osteoporosis-induced model, SLA and SLA-Sr implants were randomly inserted into the tibia and femur metaphysis of each animal. The rabbits were sacrificed after 3 and 6 weeks of bone healing, and then, removal torque values (RTVs), percentage of bone area (BA%) and percentage of bone-to-implant contact (BIC%) were analysed for the SLA-Sr and SLA implants. RESULTS: Multiple nanostructures were found on the Sr-incorporated titanium surface, and appropriate amounts of strontium ions from the SLA-Sr surface were released into the surrounding tissue within 21 days. In vivo, SLA-Sr implants displayed much more new bone around their surfaces than the SLA implants. Significantly higher RTVs and BIC% were observed for the SLA-Sr implants than for the SLA implants in both osteoporotic (p < 0.01) and healthy animals (p < 0.01) at 3 and 6 weeks. The SLA-Sr implants exhibited higher BA% in cortical bone (p < 0.01) and in cancellous bone (p < 0.05) than the SLA implants in osteoporotic rabbits at 3 weeks. CONCLUSIONS: It is suggested that Sr-incorporated surfaces treated through hydrothermal reactions have positive effects on promoting early osseointegration in both osteoporotic and non-osteoporotic rabbits.