Color stability of different aligner attachment composites following exposure to conventional and electronic...

The objective was to compare conventional and electronic cigarettes regarding the discoloration of three types of aligner composite resin attachments. Three composite resins were evaluated: Tokuyama Estelite Universal Flow, G-ænial Universal Injectable, and Filtek Z350 XT Universal Restorative. Attachments were bonded onto epoxy resin models (N = 28 teeth). Each composite group was divided into conventional and electronic cigarette subgroups (n = 14). Color measurements were performed before and after exposure with VITA Easyshade V, and ΔE₀₀ and Whiteness Index for Dentistry (WI_D) values were calculated. The chemical composition of the attachments was assessed using FTIR-ATR. Statistical analyses included one-way ANOVA, paired and independent samples t-tests. After conventional cigarette exposure, WI_D significantly decreased in all composites. Tokuyama Estelite Universal Flow exhibited a significantly smaller reduction in WI_D (- 4.06 ± 4.03) compared with G-ænial Universal Injectable (- 8.28 ± 3.56) and Filtek Z350 XT (- 10.16 ± 4.63) (p < 0.05). Following electronic cigarette exposure, WI_D increased for G-ænial Universal Injectable (p = 0.031) but decreased for Filtek Z350 XT (p = 0.009). After electronic cigarette, ΔE₀₀ was significantly higher in G-ænial Universal Injectable (4.07 ± 1.49) than in Filtek Z350 XT (2.94 ± 2.38) (p = 0.001). Significant differences between conventional and electronic cigarette exposure were observed for G-ænial Universal Injectable in ΔL, for all composites in Δb and ΔWI_D, and for Filtek Z350 XT in ΔE₀₀. Irrespective of the smoking type, all composite resins exhibited ΔE₀₀ values exceeding the clinically acceptable threshold after exposure. After conventional cigarette, whiteness index of Tokuyama Estelite Universal Flow was less affected than other resin types. Conventional cigarette induced more pronounced color changes than electronic cigarette aerosol.