Comparative Evaluation of Color Stability of Three Composite Resins in Two Mouth Rinses: An In Vitro Study

Composite resins are integral to restorative dentistry due to their aesthetic properties. However, color stability remains a significant concern, particularly when exposed to staining agents like mouth rinses.

An in vitro comparative study was conducted on 132 composite discs (n = 44 per composite type), subdivided into two subgroups each (n = 22) based on immersion in Listerine (alcohol-based) or Vantej Aqua (non-alcoholic). Baseline and post-immersion color values (L*, a*, b*) were measured using a spectrophotometer. The color difference (ΔE*) was calculated for each specimen. Statistical analysis included one-way ANOVA, Tukey's post hoc test, paired t-tests, and correlation analysis using SPSS v25.0.

Nanofilled composites exhibited the least discoloration with mean ΔE* values of 2.23 ± 0.40 in Listerine and 1.54 ± 0.30 in Vantej Aqua. Nano hybrid composites showed moderate discoloration (Listerine: 3.09 ± 0.60; Vantej Aqua: 2.30 ± 0.50), while microfilled composites demonstrated the highest color change (Listerine: 3.89 ± 0.70; Vantej Aqua: 3.00 ± 0.60). One-way ANOVA revealed statistically significant differences among all groups (F = 35.72, P < 0.001). Tukey's post hoc test confirmed significant pairwise differences, particularly between nanofilled and microfilled composites. Paired t-tests indicated significant changes in L*, a*, and b* values post-immersion across all groups (P < 0.001). Additionally, Pearson's correlation showed a strong positive relationship between composite type and ΔE* in both Listerine (r = 0.88) and Vantej Aqua (r = 0.85), with P values < 0.001.

Nanofilled composites demonstrated the highest resistance to color change, followed by nano hybrid and microfilled composites. Listerine caused more discoloration than Vantej Aqua in all groups.