Abstract
Background. The present study aimed to assess the impact of staining drinks and repolishing on the color stability of a monochromatic composite resin.
Methods. Eighty composite resin specimens (Omnichroma, Tokuyama Dental, Tokyo, Japan) were fabricated in stainless steel molds and cured with an LED light-curing device (Elipar, 3M ESPE, St. Paul, MN, USA). Initial color scores were recorded after immersion in artificial saliva for 24 hours. Subsequently, the specimens were exposed to staining drinks (artificial saliva, tea, detox drink, cherry juice, and coffee) for 4 days, followed by color score assessments. Final color measurements were obtained after repolishing with a composite resin polishing kit (CLEARFIL™ Twist DIA, Kuraray, Tokyo, Japan). Statistical analyses were conducted using SPSS 16.0 (P<0.05).
Results. Significant differences were found in staining intensity (ΔE1) between the groups; artificial saliva produced the fewest stains, whereas detox drinks produced the most. Nonetheless, no discernible variation was seen in the average ΔE1 and ΔE2 scores, indicating equivalent staining and discoloration. Color parameter shifts were noted in all the groups after staining and after repolishing. Staining drinks induced noticeable color changes, especially in the tea, detox drink, cherry juice, and coffee groups. Repolishing resulted in minor color changes but did not fully restore the original appearance.
Conclusion. ΔE scores after staining and after repolishing composite resins were similar, indicating that restoration color returned to its original state after polishing as much as after staining. Immediate replacement of stained restorations may not be needed; this study recommends repolishing before considering replacement.