Influence of drinks on resin composite: Evaluation of degree of cure and color change parameters

Resin composites represent a class of materials widely used in restorative dentistry due to patient demands for better aesthetics. In this study, the degree of conversion and color change parameters of commercial resin composite Charisma after immersion in commonly used drinks were investigated. Degree of conversion and color stability are important parameters of modern resin-based dental filling materials. The specimens, after curing, were immersed in distilled water, a sports drink, yogurt, a soft drink based on cola and red wine for 24 and 168 h at 37 °C. The degree of conversion, evaluated by Raman spectroscopy through the correlation of absorption bands related to CC aromatic and aliphatic stretching and CO free stretching, was 70% at all specimen depths. The ratios of these absorption bands for specimens after immersion in the drinks were of the same magnitude, indicating that no chemical reaction occurred at the surface. The influence of drinks on color change of filling resin was investigated by measuring the CIE-Lab-values. The color change parameters (L*, a* and b*) were significantly affected when the specimens were immersed in wine or yogurt for 24 or 168 h.