Zirconium phosphate nanonetworks for enhanced soft tissue integration and antibacterial performance of zirconia implant abutments

Effective soft tissue integration (STI) is essential for the long-term success of dental implants. Zirconia abutments are particularly preferred for anterior restorations and for patients with thin gingival biotypes due to their aesthetic appeal and metal-free composition. However, the biological inertness of zirconia presents significant challenges to achieving effective STI. In this study, we successfully fabricated colorless, uniform and stable 3D zirconium phosphate nanonetworks (ZrP nanonetworks) on the zirconia surface using a straightforward phosphoric acid hydrothermal method. These NNs not only enhance soft tissue adhesion but also exhibit mechano-bactericidal activity. In vitro results demonstrated that the modified surfaces significantly improved the adhesion, morphology, spreading, proliferation, and migration of human gingival fibroblasts (HGFs), along with changes in gene and protein expression. Moreover, they displayed potent antibacterial properties, with a reduction of Staphylococcus aureus (S. aureus) viability by 33.49 ± 1.79 % and Escherichia coli (E. coli) by 72.22 ± 7.17 %. In vivo studies further confirmed that zirconia abutments featuring these NNs inhibited bacterial vitality and facilitated optimal STI. Consequently, the multifunctional 3D NNs enhance the bioactivity of zirconia abutments, thereby improving dental implant success rates and offering promising advancements for the development and application of other zirconia-based biomaterials.