Purpose : Statins are known to enhance the biosynthesis of bone morphogenetic proteins, which could potentially lead to improved bone mass locally if attached to dental implants. The purpose of this study was to investigate the immobilization of statin drugs on titanium disks via surface treatments by surface characterization and to also determine subcutaneous tissue reactions of statin-immobilized titanium disks during the initial stages of implantation.

Method : As a statin carrier, a fluvastatin/ gelatin complex (FG complex) was immobilized on the surface of titanium disks following alkaline and dopamine treatments. The surfaces of treated disks were examined by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). In order to examine subcutaneous tissue reaction, the disks were placed under the skin of rats for 1 or 4 weeks.

Results : SEM images of alkaline-treated disks revealed a fine network structure on the titanium surfaces. XPS analysis of carbon (C) and oxygen (O) spectra suggested that the FG complex was immobilized on the titanium disks through adherent dopamine. At 1-week post implantation, lymphocytes infiltration in the connective tissue in contact with all titanium disks was observed in the subcutaneous tissue reaction of rats, and the degree of infiltration was high on the FG complex-immobilized titanium disks. No severe inflammatory reaction such as infiltration of neutrophils was observed. At more than 4 weeks post-implantation, all the disks were covered with fibrous tissue.

Conclusion : Within the limitations of this study, the FG complex could be immobilized on the titanium disks by alkaline and dopamine treatments. Also, the subcutaneous tissue in contact with the FG complex-immobilized titanium disks did not elicit any severe inflammatory response.