Color Stability and Micro-Hardness of Bulk-Fill Composite Materials after Exposure to Common Beverages

Abstract

Objectives: To assess the color stability and surface microhardness of Bulk-Fill composite materials available in the Saudi Arabia market. Methods: Five composite materials (Filtek Z350, Filtek Bulk-Fill, Tetric N-Ceram Bulk-Fill, Sonic Fill 2, and SDR) were investigated. Samples (n = 20; 10 mm in diameter and 2 mm in thickness) were fabricated using a stainless-steel mold and were immersed in tea, coffee, berry juice, and distilled water (control). Baseline (T0) shades of specimens were recorded using a spectrophotometer and after 10 (T1), 30 (T2), 60 (T3), and 90 days (T4) of immersion. Measurements were obtained against a black background and CIE L*a*b* data was used to calculate ΔE for each group. Vickers microhardness values were obtained at T0 and T4. Data was analyzed using mixed model repeated measure ANOVA at 0.05 significance level. Results: Time, material, and solution effects have statistically significant effect on ΔE. Tea was the most staining solution. Z350 was associated with the highest ΔE values while SDR showed the lowest values. No other materials showed significant difference between each other. Solutions were statistically different from each other. All materials were different from each other regarding microhardness. Conclusion: Bulk-Fill materials showed more color stability but lower microhardness values compared to universal resin control.

Color Shift, Color Stability, and Post-Polishing Surface Roughness of Esthetic Resin Composites

“…It should be noted that almost all tested materials reported ∆E values larger than 3.7 for coffee and tea after 2 weeks of immersion, and that all ∆E 8 values of the three tested solutions were above 3.7 (Table 2). This trend is in agreement with previous investigations reporting a time-dependent increase in ∆E values [11,29,30]. Still, the magnitude of color change along with other clinically relevant factors must be considered before the replacement decision is undergone in order to preserve tooth structure.…”

“…The majority of ∆E values can be attributed to positive changes in the b* parameter indicating a yellow color shift in the blue-yellow axis (Table 3). This change was expected in the coffee and tea groups as it has been reported in a previous study [11]; however, the magnitude of the yellow shift was dependent on the material and the duration of immersion reaching a maximum value of ∆b = 27.3 ± 3.7 in the Z250 tea group. Further illustration of this effect can be seen in Figures 4 and 5, which show the esthetic performance of the five resin composite materials used in the study in regards to their color shift and stability after 8 weeks in each CIE L*a*b* parameter for tea and coffee.…”

“…Resin composites can be subjected to a variety of sources of staining during their lifespan. Among the frequent sources is the dietary consumption of staining beverages [9][10][11][12]. Further, the inherent properties of the material, such as color shift and the ability to achieve a smooth lustrous surface after polishing, are very important in order to maintain an esthetic result [14,16].…”

“…This method is able to detect subtle changes in shades of dental resins and it is a widely used approach to objectively determine color changes in dental restorations expressed as numerical values without the inherent subjectivity of the operator decision-making process [4,11,[23][24][25][26][27]. However, all values of color change must be objectively considered since values of ∆E ≥ 3.7 are considered clinically unacceptable [28].…”

“…Among the major reasons for restorations discoloration is the dietary substances consumed by the patient, especially staining beverages such as tea and coffee [10]. These liquids can cause extrinsic staining of the surface of restorations and have been reported previously to affect the perceived shade of the restoration [10][11][12].…”