Titanium surface treatment by calcium modification with acid-etching promotes osteogenic activity and stability of dental implants

The aim of the present study was to prove the hypothesis that acid-etched pure titanium implants with applied calcium modification obtains remarkably high osteogenic activity and high stability in osseous tissue. To evaluate the surface structure of the implants, we performed scanning electron microscopy analysis, color 3D laser scanning microscopy analysis, and X-ray photoelectron spectroscopy analysis. To examine the biocompatibility of surface treatment implants, we inserted implants into rat long bones to evaluate insertion and removal torque values, Periotest value, the intensity of alizarin red staining, and histomorphometric analysis. Moreover, to evaluate implant biosafety, we performed a dissolution test using a thin film of calcium modified titanium and measured metal concentration in rat organs. As a result, calcium modified acid-etched pure titanium implant indicated a higher removal torque value and lower Periotest value compared with pure titanium implant, calcium-modified pure titanium implant, and acid-etched pure titanium implant. In addition, higher amounts of new bone formation and osseointegration were observed around calcium modified acid-etched pure titanium implant. Interestingly, more bone formation was observed around loaded implants than non-loaded implants. Furthermore, calcium modified acid-etched pure titanium implants had no significant toxicity by accumulation of metal ions. These findings suggested that calcium modified acid-etched pure titanium is a suitable biomaterial for implantation with superior biocompatibility, stability, and biosafety.