Color stability of composite materials to food colorants: A laboratory study

BACKGROUND: Maintaining the esthetic characteristics of direct composite restorations for a long time is relevant. The color stability of food colorants is an important esthetic characteristic of a composite material. Comparative information about the color stability of modern composite restorative materials and recommendations based on optimal clinical results for direct composite restoration are of interest.

AIM: To compare the color stability of modern composite restorative materials with the most common food colorants in laboratory conditions.

MATERIALS AND METHODS: The color stability of modern restorative materials, namely, Restavrin (Technodent, Russia), GrandioSO (VOCO, Germany), Harmonize (Kerr, USA), Charisma Classic (Kulzer, Germany), Filtek Z250 (3M, USA/Germany), and Estelite Asteria (Tokuyama, Japan), were assessed. Black coffee, black tea, carbonated soft drink cola, dry red wine, and cognac were used as coloring solutions. The samples were exposed for 14 days, and the temperature was 37 °C. The control solution was distilled water. Vita Easyshade Advance 4.0 spectrophotometer was used. The average deviation of the color of the studied samples from the reference indicators (∆E), total color stability of the studied materials (Σ ∆E_m), and “coloring potential” of different coloring solutions in relation to composite materials (Σ ∆E_c) were determined.

RESULTS: The deviation of the color of the studied samples of composite materials from the reference indicators (∆Е) depending on the coloring solution was assessed. The total color stability of the studied materials in relation to food colorants (Σ ∆E_m) as this characteristic deteriorates was as follows: Estelite Asteria, 8.64±0.08; Harmonize, 10.30±0.14; Restavrin, 12.30±0.12; GrandioSO, 12.96±0.10; Charisma Classic, 13.94±0.14; and Filtek Z250,15.82±0.15. The most aggressive food colorants with respect to composite restorative materials were black coffee (Σ ∆E_c=20.08±0.12), dry red wine (Σ ∆E_c=19.18±0.10), and black tea (Σ ∆E_c=18.54 ± 0.15).

CONCLUSION: Information about the color stability of composite materials in relation to food colorants allows planning the restoration of teeth located in an esthetically significant area, taking into account the eating habits of patients.