A Review of Antimicrobial Mechanisms of Graphene Oxide, Reduced Graphene Oxide, and Graphene Nanoplatelets: Implications for Polymer-Based Dental Materials

Graphene-based materials, including graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanoplatelets (GNPs), exhibit a relatively large surface area and tunable surface chemistry, enabling diverse biological interactions. These interactions depend on oxygen-containing functional groups, oxidation degree, lateral size, and surface charge. In dental materials, these properties support incorporation of graphene-based materials into polymer matrices to reduce microbial adhesion, inhibit biofilm formation, and limit infection-related degradation. This review critically evaluates GO, rGO, and GNPs in polymer-based dental materials, focusing on structure–property–biological response relationships and antimicrobial performance. Current evidence indicates that GO demonstrates the most consistent antibacterial and antifungal activity, mainly due to its high density of functional groups and hydrophilicity. In contrast, rGO and GNPs show more variable or moderate antimicrobial effects, often requiring surface modification, optimized composite design, or higher material loading. Here, key limitations affecting clinical application are also discussed. Several biological effects are concentration-dependent, including human cytotoxicity, host enzyme interactions, potential immune responses, long-term biocompatibility, and stability under oral conditions. By integrating mechanistic insights across graphene-based materials, this review clarifies their potential and current limitations for polymeric dental applications and identifies priorities supporting the transition from laboratory-scale research to clinical and industrial implementation strategies.