The color stability, water sorption, and solubility of ten composite resins

This study aims to evaluate the color stability and related properties including water sorption and solubility of ten light-cured composite resins in different solutions.

A total of 10 composite resins were BeautifilⅡ(B2) and Ceram. X One Universal (CXU), Charisma (CS), Charisma Diamond (CD), Denfil (DF), DX. Universal (DXU), Filtek Z250 (Z250), Filtek Z350 XT (Z350), FS-1 (FS), and Magnafill Putty (MP). Meanwhile, a total of 20 disk-shaped samples were fabricated and randomly divided into four groups (n=5), which were immersed in distilled water (control group), curry, coffee, and red wine for 28 days. The color (CIE L∗a∗b∗) was measured by a spectrophotometer at baseline and 1, 7, 14, 21, and 28 days after immersion, and the color differences were calculated. Water sorption and solubility values were measured ba-sed on ISO 4049: 2019. In addition, three-way ANOVA was used to evaluate the influence of resin materials, solutions, and immersion time on discoloration results, meanwhile, one-way ANOVA was used to compare the water sorption values and solubility values of different materials.

All samples showed a certain degree of color change with time. Color differences were significantly influenced by materials, solutions, and immersion time (P<0.001). The color changes of the measured materials at any time point: curry>red wine>coffee>distilled water. Thus, all materials showed clinically unacceptable discoloration (ΔE>3.3) after immersing in staining curry, coffee, and red wine for 7 days. Therefore, when immersed in curry for 28 days, CS and DXU had the smallest and the largest color difference. In addition, when immersed in coffee for 28 days, FS showed the smallest color change and DXU showed the largest. Moreover, when immersed in red wine for 28 days, FS showed the smallest color change and Z350 showed the largest. Furthermore, MP and CXU had small color differences in all solutions. Meanwhile, Z350 had the highest water sorption and MP had the lowest. The solubility values of CS and CD were significantly higher than those of other materials.

The color stability of light-cured composite resin is materials-depended and affected by pigment types and immersion time. Thus, MP and CXU have better color stability. MP has low water sorption.