Piezoelectric g-C3N4/rGO heterojunction remodels the periodontitis immune microenvironment to promote neurovascular-bone coupled osseointegration.

Abstract

Dental implant restoration is required for tooth loss caused by periodontitis; however, the success rate of implantation in periodontitis patients is significantly lower than that in healthy individuals. On the one hand, biofilm colonization compromises early osseointegration of the implant; on the other hand, the chronic inflammatory microenvironment associated with periodontitis undermines long-term implant stability. Therefore, there is an urgent need for a strategy that integrates both antibacterial and osteogenic microenvironment-modulating functions to promote early osseointegration and long-term stability of dental implants. Herein, a two-dimensional nano-heterostructure was fabricated using g-C₃N₄ and rGO to construct a piezoelectric conductive hydrogel (CN/rGO) for implant restoration in periodontitis patients. Upon ultrasound stimulation, the CN/rGO hydrogel generates a piezoelectric field around the implant: in the early stage, it exerts antibacterial effects to promote initial osseointegration; over the long term, it modulates the immune microenvironment, thereby facilitating neurovascular regeneration and enhancing sustained osseointegration. Notably, inhibition of the JAK-STAT signaling pathway plays a pivotal role in CN/rGO-mediated macrophage phenotype regulation and reversal of the inflammatory microenvironment. This combined strategy of early piezoelectric antibacterial activity and long-term osteogenic microenvironment modulation holds significant implications for promoting early osseointegration and long-term stability of implants in periodontitis patients. The piezoelectric heterostructure-based design proposed in this study promotes neurovascular-guided bone regeneration around implants under inflammatory conditions, offering a feasible approach for improving implant success rates in periodontitis patients, preventing peri-implantitis, and enhancing the full-cycle service performance of dental implants.