Simvastatin promotes osteogenesis around titanium implants: A histological and histometrical study in rats

Objectives: Hydroxymethylglutaryl-coenzyme A reductase inhibitors, the so-called statins, have been widely used for hyperlipidemic patients, and it was recently reported that it promoted bone formation. In the present study, we examined the effect of simvastatin on the promotion of osteogenesis around titanium implants. Materials and methods: Ten 30-week-old rats received pure titanium implants in both tibiae, and were then divided into experimental and control groups. The experimental group was administered simvastatin daily. Thirty days later, all animals were killed and then specimens were prepared. The bone contact ratio (BCR) to the implant and bone density (BD) around the implant, as well as histological findings, were obtained. Results: In the control group, newly formed bone could be seen around the implants. It was seen to be in direct contact with the implant surface, but otherwise unmineralized connective tissue was occasionally interposed. In the medullary canal, a scanty amount of bone trabeculae was observed. In the experimental group, in contrast, thicker bone trabeculae were abundantly seen in the medullary canal and showed a mesh-like structure. In the histometrical observations, both BCR and BD of the experimental group were significantly greater than those of the control group. Conclusion: The administration of simvastatin increases the value of both BCR and BD. This drug may have the potential to improve the nature of osseointegration.