This narrative review provides a comprehensive overview of the potential of plant-derived polyphenols in restorative and preventive dentistry. As natural bioactive compounds such as polyphenols reshape the oral microbial ecology by attenuating virulence, inhibiting quorum-sensing communication, disrupting extracellular polymeric substance (EPS) formation, and reducing acidogenicity within dental biofilms. Beyond their antimicrobial effects, polyphenols can protect host tissues, namely, enamel, dentin, and gingiva, by cross-linking collagen fibrils, suppressing matrix metalloproteinase (MMP) activity, and modulating inflammatory pathways. Experimental, in situ, and clinical evidence consistently demonstrated improved bond durability at the dentin–resin interface. The most compelling data support the use of primers containing proanthocyanidins, quercetin, epigallocatechin gallate (EGCG), and resveratrol. In preventive applications, catechin-based varnishes have demonstrated remineralization effects comparable to those of fluoride varnishes. Conversely, pomegranate extract–enriched mouthrinses, in the presence of fluoride, could enhance both anti-demineralization and antibiofilm activity. In the context of implants and dental prostheses, the polyphenol-functionalized coatings, particularly those based on tannic or caffeic acid, would reduce biofilm formation and provide corrosion resistance for metallic surfaces. Nevertheless, several formulation challenges remain, including rapid oxidation, limited solubility, and discoloration, all of which require careful management. Strategies such as dose optimization, solvent selection, covalent stabilization, and microencapsulation are recommended to overcome these limitations. For broader and more effective clinical translation, standardization of multispecies laboratory models and harmonization of clinical endpoints are essential. Furthermore, future longitudinal trials are needed to bridge the gap between laboratory findings and clinical performance. Ultimately, with the design of innovative delivery systems and long-term monitoring of parameters such as restoration survival, secondary caries, periodontal health, and color stability, polyphenols hold promise to define a new generation of antibacterial, biocompatible, and aesthetically stable dental materials.
