Effect of surface alkali-based treatment of titanium implants on ability to promote in vitro mineralization and in vivo bone formation.

This study investigated whether a novel alkali-based surface modification enhances in vitro mineralization as well as in vivo bone formation around titanium (Ti) implants in a femoral condyle model of 36 male Wister rats. All implant surfaces were grit-blasted and then received either acid-etching treatment, alkali-based treatment, or were left untreated (controls). Histological and histomorphometrical analyses were performed on retrieved specimens after 4 and 8weeks of healing to assess peri-implant bone formation. Results of implants surface characterisation showed notable differences in the topography and composition of alkali-treated surfaces, reflecting the formation of submicron-structured alkali-titanate layer. In the in vitro test, alkali-treated Ti surfaces showed the ability to stimulate mineralization upon soaking in simulated body fluid (SBF). In vivo histomorphometrical analyses showed similar values for bone area (BA%) and bone-to-implant contact (BIC%) for all experimental groups after both 4- and 8-week implantation periods. In conclusion, the surface topography and composition of the grit-blasted Ti implants was significantly modified using alkali-based treatment. With respect to the present in vivo model, the biological performance of alkali-treated Ti implants is comparable to the commercially available, grit-blasted, acid-etched Ti implants. STATEMENT OF SIGNIFICANCE: Since success rate of dental implants might be challenged in bone of low density, an optimum implant surface characteristic is demanding. In this work, alkali treatment of Ti implants showed significant advantage of surface mineralization upon soaking in simulated body fluid. Using an in vivo rat model, Ti surfaces with either acid-etching treatment or alkali-based treatment evoked robust bone formation around Ti implants. Such information may be utilized for the advancement of biomaterials research for bone implants in future.