COLOR STABILITY OF A NANOFILL COMPOSITE: EFFECT OF DIFFERENT IMMERSION MEDIA

Objective: The aim of this in vitro study was to evaluate the color stability of a nanofill composite resin (Filtek Z350) in different immersion media. Materials and methods: Twelve resin-based composite specimens were prepared using a silicon cylindrical mold measuring congruent to 1mm of thickness and congruent to 10mm of diameter. Specimens were light-cured for 40 s from both sides using a LED Radii at 1400 mW/cm(2) and were randomized into 4 groups (n=3) according to immersion media: coffee, yerba mate, grape juice or water (control solution). A digital spectrophotometer was used to evaluate the color changes at baseline and at 1-week after immersion in each solution. Specimens were stored in the different staining media for 4 h/day during 1 week. The color differences (Delta E) were analyzed by paired t-test and one-way ANOVA with complementary Tukey test (p<0.05). Results: After 1-week of immersion, a perceptive color change for the group stored in the grape juice compared to baseline (p=0.008) was observed. Coffee and yerba mate did not show any color changes visible for the human eyes or significantly different from the control group (p>0.05) Conclusions: The findings of the present study suggest that the tested nanofill resin-based composite was susceptible to staining by substances present in the grape juice.