Abstract
Abstract
Objective:
The aim of this in vitro study was to evaluate and compare the color stability of conventional universal resin composites and so-called biocompatible resin composites following exposure to common dietary staining agents.
Materials and Methods:
Sixteen resin composites from five manufacturers were investigated, including conventional universal composites and biocompatible composites formulated to reduce or eliminate specific methacrylate monomers. Disc-shaped specimens (10 mm × 1 mm) were fabricated in shade A2 and polymerized using a LED light-curing unit. Baseline color measurements were performed after 24 hours of storage at 37°C using a reflection spectrophotometer according to the CIE Lab* color system. Specimens were subsequently immersed for six weeks in coffee, red wine, curry in oil, or distilled water (control) at 37°C. Post-staining color measurements were recorded using the same protocol. Color differences between baseline and post-staining measurements were calculated using the CIEDE2000 (ΔE₀₀) formula.
Results:
Composite discoloration was significantly influenced by both the type of staining medium and the composite material (p < 0.001), with a significant interaction between these factors. Coffee and red wine produced the greatest color changes, whereas curry in oil and the control condition resulted in lower ΔE₀₀ values. Marked differences in color stability were observed among materials: PUREFILL2 Bio+ A2 and ENAMEL PLUS HRi UE2 exhibited the highest discoloration, while MHC A2 and APT A2 demonstrated the lowest ΔE₀₀ values. Exclusion of the control group enhanced discrimination among composites under effective staining conditions, revealing a consistent ranking of materials across staining agents. Comparable results were obtained under both white and black background conditions.
Conclusion:
Within the limitations of this in vitro study, the color stability of resin-based composites was influenced by both material composition and staining medium. Comparative evaluation of conventional and biocompatible resin composites provides relevant information regarding the aesthetic durability of modified resin formulations under staining conditions.