Multimodal and Advanced Characterization of Dental Resin Composites: Insights into Beverage-Induced Degradation.

: Composite dental restorations are continuously exposed to dietary substances, which may compromise their structural integrity. This study aimed to assess the chemical and mechanical effects of coffee, red wine, and Coca-Cola on two widely used commercial resin composites, Herculite Ultra XRV and Omnichroma. : Forty disk-shaped specimens (20 per material) were immersed for 10 days in the selected beverages. Changes in chemical composition were analyzed using Fourier Transform Infrared (FTIR) and Raman spectroscopy, while Vickers microhardness testing evaluated surface hardness. : FTIR and Raman analyses revealed that coffee and red wine caused the most substantial chemical degradation, particularly in carbonyl (C=O), aromatic (C=C), and siloxane (Si-O-Si) groups. Herculite XRV demonstrated higher chemical stability, while Omnichroma showed more pronounced molecular degradation. In contrast, microhardness testing indicated that Omnichroma maintained better surface hardness compared to Herculite XRV after exposure. Across all solutions, Coca-Cola induced the least effect. : The tested beverages significantly affected both the chemical and mechanical properties of the resin composites. Omnichroma exhibited superior mechanical durability, while Herculite XRV showed greater resistance to chemical degradation. These results highlight the importance of material composition in restorative dentistry and support the development and selection of composites with improved resistance to acidic and staining agents to ensure long-term clinical performance.