The Effect of Whitening Agents (Whitening Rinse and Carbamide Peroxide) on Stained Flowable and Packable Composite...

This study aimed to verify the effects of whitening agents on the color stability of aligner attachments made from flowable and packable composite resins after staining with coffee and wine.

Two composite groups were used for attachment preparation on epoxy resin master models: G-ænial Universal Injectable flowable (Group 1, N = 42) and G-ænial Posterior packable (Group 2, n = 42). Initial staining of samples was performed with coffee and red wine respectively, with a total period of 6 days representing 6 months of consumption. After staining, each main group was randomly divided into 3 groups related to distilled water as the control (Distilled Water (DW), n = 14) and whitening agents (Whitening Oral Rinse (WR), n = 14) (Carbamide Peroxide 22% (CP), n = 14) for a 14-day test period. Before staining (T0), after staining (T1), and after whitening (T2), color measurements were made with Vita Easy Shade V. ΔE₀₀ formula was used to determine color differences between T0-T1 (ΔE₀₀₁), T1-T2 (ΔE₀₀₂) and T0-T2 (ΔE₀₀₃) color measurement periods. Also, attachments' whiteness change before and after whitening procedures was calculated using the Whiteness Index for Dentistry (WI_D) formula considering as ΔWI_D1 = WI_D(T2) - WI_D(T0) and ΔWI_D2 = WI_D(T2) - WI_D(T1).

After immersion in staining solutions, ΔE₀₀₁ values of Group 2 were significantly higher than of values of Group 1 (p < 0.001). In Group 1, ΔWI_D2 values in the WR and CP groups were found to be significantly higher than measurements in the DW group (p = 0.049 and p = 0.001). In Group 2, the value of ΔE₀₀₂ for subgroup CP was significantly higher than that for DW group (p = 0.023). Also, the ΔE₀₀₃ measurement of the WR group was higher than the measurement of the CP group (p < 0.001). In Group 2, the ΔWI_D1 measurement of the CP group was lower than the measurements of the DW (p < 0.001) and WR (p = 0.014) groups. According to ΔWI_D2 measurement in Group 2, CP measurements were higher than DW (p < 0.001) and WR (p = 0.024) measurements. Statistically significant differences were determined between the composite types for DW, WR, CP whitening types in terms of ΔE₀₀₃ and ΔWI_D1 measurements and between the composites for CP whitening type in terms of ΔWI_D2 measurements (p < 0.05). For all significant differences, measurements for Group 2 were found to be higher than for Group 1.

The color change of packable composite was more pronounced than that of the flowable composite after staining. Between whitening and staining stages, especially in packable composite group, carbamide peroxide whitening agent significantly effected the color and whiteness of the attachments compared to control distilled water group.