Effect of Surface Modification on the Primary Stability of Dental Implants by Plasma Oxidation and Storage Treatment

Plasma oxidation could produce an oxidized surface, resulting in a graded TiO2−x film layer and significantly improving dental implant hydrophilicity and biocompatibility. Unfortunately, these features are gradually lost by the influence of the environment. In this study, alkali storage was used to improve these characteristics at room temperature. Titanium samples were divided into sandblasting acid-etching (SLA), oxidation (SLA samples that were oxidized), and storage (SLA samples that were oxidized and stored in 0.1 mol/L NaOH solution) groups. We measured the surface properties of each group, including the roughness, chemical composition, and hydrophilicity of these materials. We investigated the effects of titanium storage on cell responses, including cell attachment, proliferation, differentiation. We also investigated the osseointegration of the stored titanium implants. The results showed that the storage process maintains the superhydrophilic properties of oxidation treatment. Oxidized samples promoted cell responses. The descending order of biocompatibility was storage > oxidation > SLA. Furthermore, oxidation and alkali storage had significant effects on bone growth at the early stage of the implant. These results suggested that alkali storage can suitably maintain the surface characteristics of plasma oxidation, and the combination of oxidation and storage treatment can improve the primary implant stability.