Advances of Metal-Based Nanomaterials in the Prevention and Treatment of Oral Infections

The complicated environment of the oral cavity presents significant challenges to traditional antibacterial approaches, which has driven the exploration of novel therapeutic strategies. Metal-based nanomaterials (MNMs), with diverse antibacterial mechanisms (e.g., membrane disruption, oxidative stress) and evolution from empirical to theory-guided design, exhibit immense potential. This review introduces the pioneering Hierarchical Response Strategy Framework, systematically classifying MNM therapeutic systems into three progressive levels: Primary category, comprising MNMs that exert spontaneous antibacterial effects based on inherent physicochemical properties (e.g., ion release); Secondary category, including MNMs with precisely controlled antibacterial actions by microenvironmental or stimulus-responsive mechanisms (e.g., light-induced ROS); and Tertiary category, encompassing MNMs that integrate antibacterial and regenerative functions for multidimensional therapy (e.g., remineralization). Through this framework, the authors elucidate MNMs' transition from single-function to precision-controlled, multifunctional synergy, analyze the impact of metal elements and structural design on efficacy, and summarize their applications in dental caries, endodontic infections, and periodontal disease, etc. This framework offers a novel perspective on existing research and a theoretical foundation for the rational design of next-generation precise, smart, and comprehensive anti-infective materials.