Color Change Over Time in One-Shade Composite Restorations of Non-Carious Cervical Lesions After In-Office Dental Bleaching: A Controlled Clinical Trial

Objectives This double-blind and split-mouth randomized controlled trial evaluated color change progression in non-carious cervical lesions (NCCLs) restored with one-shade or multi-shade resin composites following in-office dental bleaching. Methods and Materials Eighty-four NCCLs were restored using one-shade (Vittra Unique, FGM) or multi-shade (Vittra APS, FGM) resin composites (n = 42). Each participant received two restorations (one per hemiarch). Afterward, two sessions of in-office bleaching with 35% hydrogen peroxide were performed. Color progression was assessed using WI D , ΔE ab , and ΔE 00 at baseline, after each bleaching session, and one-month post-bleaching. Color matching between the cervical (restoration) and middle (adjacent tooth structure) thirds was also evaluated. Secondary outcomes included tooth sensitivity, and clinical performance according to FDI criteria. Data were analyzed using paired t-tests, linear mixed models, and McNemar test (α = 0.05). Results In the middle third, no differences between materials were observed for any color parameter (p > 0.05). In the cervical third, the one-shade composite showed higher WI D values over time than the multi-shade composite (p < 0.05), whereas no differences were observed for ΔE ab or ΔE 00 progression (p > 0.05). After one month, the multi-shade composite showed greater color mismatch than the one-shade composite (p < 0.05). Tooth sensitivity did not differ between groups (p = 1.00). All restorations were classified as clinically very good according to FDI criteria. Conclusion The one-shade composite showed greater whitening progression in the restored cervical area and lower color mismatch after bleaching, while both materials presented similar short-term clinical performance and participant-related outcomes. Clinical Significance Single-shade composite may promote greater short-term whitening progression in the restored cervical area and improved color matching performance after in-office bleaching compared with multi-shade composites in NCCLs. Clinically, this may support minimally invasive approaches by reducing the need for restoration replacement and preserving tooth structure.