Statins are
cholesterol-lowering drugs that have been reported to promote bone formation. The purpose of this study was to investigate the effect of
simvastatin on the enhancement of bone formation around
titanium implants. Thirty-week-old female rats received pure
titanium implants in both tibiae. The animals were intra-peritoneally administered 0, 0.125, 1, 5 or 10 mg kg(-1) of
simvastatin daily. After 30 days, the animals were sacrificed, and specimens were prepared. The bone contact ratio of the implant, bone density in the medullary canal and percentage of cortical bone were obtained. Markers for bone turnover were also measured using sera collected at the time of
euthanasia. In the medullary canal, a scanty amount of bone was observed in the 0, 0.125 and 1 mg kg(-1) groups. In contrast, in both the 5 and 10 mg kg(-1) groups, thicker bone trabeculae were abundant. Histometric observations showed that the bone contact ratio and the bone density of both groups were significantly greater than those of the other groups (anova, P < 0.01). However, no significant difference in the percentage of cortical bone was found between groups. Serum chemistry showed that
statin increased bone formation markers and decreased
bone resorption markers. In conclusion, although the dose equivalent to that used in human patients with
hypercholesterolemia was not effective, a
simvastatin dose of 5 mg kg(-1) or higher increased medullary bone formation around the
titanium. In contrast, no effect of
simvastatin on pre-existing cortical bone was indicated.