Comparative analysis of color stability in preheated vs. non-preheated injectable composites under different curing protocols: an in-vitro study

This in vitro study aimed to evaluate the effect of composite preheating and light-curing mode on the colour stability of a nanohybrid and a nanofilled resin-based composite after exposure to a controlled coffee-staining protocol. The data presented represents a single observation and is not a part of another research project. Eighty-disc shaped specimens (10 mm × 2 mm) fabricated from G-aenial Universal Injectable and Filtek Supreme Flowable were assessed under different preheating and curing protocols, subdivided into 8 subgroups. All specimens exhibited colour changes exceeding the clinically perceptible threshold (ΔE > 2.7) after staining. Mean colour change values ranged from 12.0 to 26.5. G-aenial Universal Injectable showed significantly greater discolouration than Filtek Supreme Flowable ( p < 0.001). Polywave curing resulted in higher mean ΔE values compared with monowave curing ( p < 0.001). Preheated specimens demonstrated greater colour change than non-preheated specimens for both materials. The highest discolouration occurred in the G-aenial preheated polywave subgroup (ΔE = 26.5), while the lowest occurred in the Filtek preheated monowave subgroup (ΔE = 12.0). Composite formulation, preheating, and curing mode were found to significantly influence colour stability following simulated coffee exposure.