Impact of kombucha, coffee, and turmeric beverages on the color stability of a single-shade versus a multi-shade resin-based composite: Study

A new study published in PeerJ has found that turmeric causes the most significant discoloration in dental resin-based composites (RBCs) compared to coffee and kombucha, with single-shade RBCs exhibiting poorer color stability than multi-shade composites. Researchers tested 60 composite specimens using two types of materials: a single-shade RBC with an advanced polymerization system (APS) (Vittra APS Unique, FGM Dental Group, Brazil) and a conventional multi-shade universal RBC (Tetric N-Ceram, Ivoclar Vivadent, Germany). Each group was subdivided and immersed in turmeric, coffee, or kombucha for 12 days, and color changes (ΔE*ab and ΔE00) were measured at baseline, day 6, and day 12. Results showed that turmeric caused the highest degree of discoloration (p < 0.001), followed by coffee and then kombucha. Additionally, the universal RBC demonstrated significantly better resistance to staining compared to the single-shade APS-based composite (p = 0.004). Researchers concluded that time, staining medium, and material type all significantly influenced color changes (p = 0.005 for three-way interaction). These findings highlight a potential esthetic limitation of single-shade composites, particularly when patients consume beverages or foods containing strong chromogens like turmeric. While turmeric’s staining potential was already well-documented on natural teeth, this study adds valuable evidence of its impact on modern composite resins, especially those marketed for universal shade-matching convenience. Clinicians may need to consider this when selecting materials for patients with high exposure to staining agents. The authors recommend further long-term studies to confirm these results and to evaluate whether surface finishing, polishing, and sealing techniques can mitigate discoloration over time. This study underscores the importance of patient education regarding dietary habits and the impact of staining beverages on restorative esthetics, especially for those seeking long-lasting cosmetic results.