A Sericin@Cu Coating on Zirconia to Orchestrate a Sequential Antibacterial-to-Regenerative Cascade for Enhancing Peri-Implant Soft Tissue Seal.

Abstract

A stable biological seal is essential for dental implant longevity by preventing peri-implantitis. Zirconia abutments, though aesthetically pleasing, suffer from a bioinert surface that hinders this seal. Here, we introduce a Sericin@Cu coating that orchestrates a sequential healing cascade, in which the cross-linked sericin not only provides a stable platform for cell adhesion but also mediates the controlled release of copper ions (Cu²⁺). Initially, a pH-responsive release of Cu²⁺ provides targeted antibacterial action against early infection. Subsequently, a sustained, low-concentration release of Cu²⁺ promotes angiogenesis, establishing a rich vascular supply that fuels the subsequent stages of soft tissue regeneration. This paves the way for the final stage, where sericin guides fibroblast proliferation and maturation, culminating in a dense, well-organized fibrous seal. These effects were validated in a rat oral implant model with S. aureus infection, where the coated abutments significantly outperformed controls in establishing a powerful soft tissue barrier. This bio-inspired coating offers a potent strategy to overcome the limitations of zirconia by actively programming the formation of a robust and lasting peri-implant seal.