Single-Cell Analysis Of Steady-State Peri-Implant Microenvironment

This study employed single-cell sequencing to investigate the cellular and molecular features of the steady-state peri-implant microenvironment in rats, aiming to elucidate mechanisms underlying its homeostasis. Fifteen 4-week-old male SPF-grade SD rats (ethics approval: 2022kq008) were divided into three groups: alveolar process, healing extraction socket, and peri-implant tissue. Single-cell sequencing mapped microenvironmental cell populations, functional traits, and intercellular interactions. Findings were validated via qPCR and immunofluorescence. Cellular composition: The peri-implant microenvironment exhibited enriched stromal/epithelial cells and reduced immune cells. Functional subsets: Osteoblast-associated fibroblasts and infection-resistant epithelial subsets were highly expressed near implants. Immune dynamics: Adaptive immunity was enhanced, while innate immunity declined. Key mechanism: C1qahi macrophages regulated fibroblast activity via the SPP1-CD44 axis, potentially sustaining microenvironmental homeostasis. This study established the first single-cell atlas of the steady-state peri-implant microenvironment, identifying its unique cellular architecture and functional dynamics. It revealed that C1qahi macrophage-mediated SPP1-CD44 signaling in fibroblasts is a pivotal mechanism for maintaining implant microenvironmental stability. These findings provide novel insights into strategies for improving long-term implant success.