Surface modification of Ti dental implant by bioactive coatings: experimental and theoretical studies

Life inevitably leaves its traces on the teeth. A mechanical trauma, an accident or untimely treated caries and periodontitis frequently lead to permanent tooth loss. Dentists and dental specialists have a contemporary solution: the small titanium body fixed into the jawbone acts as the base for single crowns, larger bridges or dentures. Titanium dental implants, in the form of screw (endosseous implants), are various-age appropriate secure solution and are the most used implants. Since a dental implant, generally metal-made, represents a foreign body for the patient, many difficulties can occur. Therefore, for successful implant application, the dental industry has to consider all relevant factors that are related to dental reconstruction and restoration like biocompatibility, osseointegration, corrosion resistance, implant geometry design, mechanical stability, and implant/bone and implant/surrounding tissue interactions. Once the implant is placed within the jaw, it should rapidly osseointegrate with surrounding bones and tissues and create a stable implant/surrounding bone interface. It is clear, implant-bone and implant-surrounding tissue interactions are affected by the implant surface microstructure, composition, morphology, roughness and hydrophilicity. Hence, surface engineering plays a significant role in the improvement of the implantation process, especially osseointegration. Many studies report about surface modification of dental implants (e.g., sandblasting, acid etching, anodization, self-assembling etc.) in order to optimize and improve their surface characteristics and enhance implantation. In this study, the titanium implant surface was functionalized by chemisorption of osseoinductive molecule using a facile and effective approach. The morphology of the modified implant surface, Ti/TiO2/bioactive coating, was examined by SEM and wetting properties by contact angle measurements. Electrochemical properties of the Ti/TiO2/bioactive coating were studied in vitro in artificial saliva solution using electrochemical impedance spectroscopy. The experimental findings were corroborated by means of DFT calculations. The formation mechanism of bioactive implant coating was proposed considering experimental results and a computational study of Gibbs free energies of bioactive molecule/TiO2 molecular interactions.