The effects of bleaching products on the color stability of ion-releasing restoratives

Contemporary ion-releasing restoratives were developed to prevent secondary caries while maintaining the mechanical strength and esthetic qualities of conventional composite resins. Dental bleaching procedures may affect the physical properties of restorations. This study aimed to evaluate the effect of bleaching agents on the color stability of these ion-releasing restoratives.

Forty-five disc-shaped specimens of Activa Bioactive, Beautifil II LS, Cention-N, Riva LC HVGIC, and Luna were fabricated using customised cylindrical Teflon molds. Baseline CIE-Lab color measurements were recorded using a spectrophotometer. Specimens were assigned to three subgroups (n = 15) and exposed to take-home bleaching (Pola Night), in-office bleaching (Pola Rapid), or artificial saliva (control) per manufacturers' protocols. Color measurements were repeated at 24 h (T1), two weeks (T2), and one month (T3), with color change (ΔE*) calculated. Data were analyzed using two-way ANOVA, two-way repeated measures ANOVA and post-hoc tests (p < 0.05).

ΔL* ranged from - 0.02 ± 1.23 to 4.94 ± 1.37; Δa* from - 0.31 ± 0.12 to 0.65 ± 0.13; Δb* from - 3.08 ± 1.24 to 0.31 ± 0.86; and ΔE* from 0.94 ± 0.48 to 5.99 ± 1.33. At T1, Riva LC HVGIC showed the highest ΔE*, while Luna had the least. Both bleaching products had similar effects on ΔE*. Activa Bioactive's ΔE* increased significantly from T1 to T3, reaching the highest value at T3.

The impact of bleaching on ion-releasing restoratives' color stability was material-dependent.