Interface effects on regulating the behaviors of human gingival fibroblasts on titanium by Zn-PIII

To understand the interface effects between human gingival fibroblasts (HGFs) and the titanium substrate for soft tissue sealing, zinc (Zn) was incorporated into titanium by plasma immersion ion implantation (PIII) in the work, and the durations of 30, 60 and 90 min were adopted for serials of Zn content on titanium to identify the possible dose-effect relationship. Results showed that the implanted Zn formed metallic Zn and zinc oxide on the surface, and the Zn content increased with the extension of implantation time. The release of Zn ions occurred in the saline solution, but the amounts of released ions were inconsistent with the Zn content of implanted samples and their corrosion behaviors, indicating the different reaction activities among the sample surfaces. Moreover, in vitro studies disclosed that the incorporated samples were beneficial to the adhesion, proliferation, and migration of HGFs with appropriate dose of released Zn ions as well as the surface activities, as the fact it was not a directly proportional dose-effect relationship between released Zn ions and the behaviors of cells. It was suggested that Zn-PIII provided an approach to improve the soft tissue sealing of titanium through interfacial activities of implanted samples to regulate the behaviors of HGFs and the usage of Zn ions followed a synergistic manner.