Peri-implantitis represents an inflammatory condition characterized by the presence of plaque-related soft and hard tissue damage surrounding dental implants, often resulting in progressive alveolar bone loss and, ultimately, implant failure. Black phosphorus (BP), a novel two-dimensional (2D) material that has recently emerged in the biomedical field, has attracted increasing attention due to its unique osteogenic properties and exceptional antibacterial and antioxidant characteristics. Additionally, its outstanding biomedical attributes enhance angiogenesis and nerve regeneration. Compared to other biomaterials, its high specific surface area, high photothermal conversion efficiency, and complete biodegradability make BP a promising candidate for treating infection-related bone defects. This article reviews the biological properties of BP nanosheets (BPNS) and discusses their potential applications in the context of peri-implantitis, aiming to provide fresh insights for future research and applications of BPNS.