BMC Oral Health. 2026 May 2. doi: 10.1186/s12903-026-08511-3. Online ahead of print.
ABSTRACT
BACKGROUND: The popularity of white teeth among patients has led to the introduction of various restorative materials with bleach shades. However, color change in these materials remains a drawback to the long-term success of such restorations. The aim of this study was to compare the effects of different light-curing intensities on the color change of three Resin-Based Composite types in two shades after immersion in coffee.
METHODS: In this in vitro study, 120 samples of three types of Resin-Based Composite were prepared, including Vit-l-escence in two shades (PN and OS), Gradia in two shades (A2 and XBW), and Filtek Z350 XT in two shades (A2 and XW). They were polymerized at intensities of 1000 mW/cm² and 1400 mW/cm² using a Valo light-curing device for 20 s. All specimens were incubated in distilled water at 37 °C for 24 h. After measuring the initial color, all specimens were immersed in a coffee solution at 50 °C for 7 days. The final color of the specimens was re-evaluated, and ΔE00 was calculated. Data were analyzed using One and Three-way ANOVA, and Post hoc Tukey HSD test in SPSS 26. P < 0.05 was considered statistically significant.
RESULTS: Resin-Based Composite type (P < 0.001), Resin-Based Composite shade (P < 0.001), and light-curing intensity (P < 0.001) had a significant effect on color change. The greatest color change was observed in Vit-l-escence (bleach shade, light-curing intensity of 1000 mW/cm2) and the lowest color change was in Gradia Direct (normal shade, light-curing intensity of 1400 mW/cm2). The higher light-curing intensity (1400 mW/cm2) significantly reduced color change in Gradia for both bleach and normal shades, as well as in Vit-l-escence for both bleach and normal shades.
CONCLUSIONS: Gradia Direct and Vit-l-escence showed less significant color change at a light-curing intensity of 1400 mW/cm² compared to 1000 mW/cm²; however, Filtek Z350 did not exhibit this result. The color change of bleach shade Resin-Based Composites was also greater than that of the normal shades. Thus, light-curing intensity may influence the color stability of Resin-Based Composites, and this effect likely depends on multiple factors, such as Resin-Based Composite shade and type.
PMID:42067920 | DOI:10.1186/s12903-026-08511-3
