Introduction

Aesthetic longevity is a crucial parameter in dentistry, with color stability being a key determinant of clinical success. Used for their aesthetic appeal, composite resins are susceptible to discoloration when exposed to dietary substances. This study investigated the discoloration behavior of monoshade and multishade composite resins when exposed to staining beverages over time.

Objectives

The objective of this study was to evaluate the color stability of a monoshade composite versus a multishade composite after immersion in common beverages for 28 days.

Material and methods

Sixty disc-shaped specimens (n = 30 per material) were fabricated and polished using monoshade (Vittra APS Unique) and multishade (Brilliant NG, Coltene) composites. Each group was divided into three subgroups (n = 10) based on immersion media (artificial saliva, beer, and tea), and subjected to thermocycling. Color changes were assessed at baseline, after 24 hrs., on day 7, and on day 28 using a colorimeter and CIEDE2000 formula. Data were analyzed using repeated measures ANOVA and paired t-tests.

Results

Both composites showed time-dependent discoloration. Monoshade resin (Vittra APS Unique) exhibited marked changes in beer from 24 hrs. (ΔE = 1.89) to 7 days (ΔE = 6.99), while saliva affected both materials during the same time period. Beer had minimal impact on the multishade resin (Brilliant NG, Coltene), whereas tea consistently stained the multishade composite (Brilliant NG, Coltene) at all time points (24 hrs.: ΔE = 5.22, day 7: ΔE = 5.44, and day 28: ΔE = 4.82). Overall, the monoshade resin (Vittra APS Unique) was more prone to staining than the multishade composite (Brilliant NG, Coltene).

Conclusions

Color stability of composite resins is influenced by the type of restorative material and staining medium. Tea posed the highest risk of discoloration, particularly for multishade (Brilliant NG, Coltene) compo­site, while the monoshade resin showed broader susceptibility across the tested beverages.