Zinc ions improve the stability of titanium implants under the condition of osteoporosis / 中国组织工程研究

ABSTRACT

BACKGROUND:Zinc can improve bone reaction to titanium implants through regulation of osteoblast activity under the condition of osteoporosis. OBJECTIVE:To study the zinc ions effect on improving the stability of titanium implants under the condition of osteoporosis. METHODS:After removal of the ovary, 28 female Sprague-Dawley rats presented with osteoporosis symptoms for 12 weeks and then, they were randomly divided into two groups. Two kinds of titanium implants with (experimental group) or without zinc (control group) were inserted into the bilateral femoral metaphysis longitudinal y in the ovariectomized rats, separately. Three rats were selected from each group for double fluorescence labeling examination. Mineral apposition rate was calculated at postoperatively 6 weeks. Another four rats were selected from each group for histomorphometry analysis at postoperatively 12 weeks. Biomechanical test was in the remaining rats in the two groups to calculate the maximum push-out force and maximum shear force at 12 weeks postoperatively. RESULTS AND CONCLUSION:The double fluorescence labeling examination revealed that the mineral apposition rate was improved in the experimental group as compared with the control group (P<0.05). New bone formation occurred in the two groups. However, larger new bone amount, higher bone area ratio and bone-to-implant contact were detected in the experimental group (P<0.05 or P<0.01). The maximum push-out force and maximum shear force were also superior in the experimental group to the control group (P<0.05 or P<0.01). These findings indicate that zinc ions are capable of promoting bone formation and improving implant fixation in ovariectomized rats.