Color changes of light-cured composite resins

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Color Science

Background:

• Light-cured composite resins are widely used in dental restorations.
• Understanding their long-term color stability is crucial for aesthetic outcomes.
• Previous studies have indicated potential for color alteration over time.

Purpose of the Study:

• To evaluate the color stability of Silux Plus light-cured composite resins.
• To quantify color changes over a one-year period under simulated oral conditions.
• To assess the influence of background color on colorimetric measurements.

Main Methods:

• Composite resin disks (Silux Plus, various shades) were light-cured for 2 minutes.
• Specimens were stored in artificial saliva at 37°C.
• Colorimetric values (delta E*ab) were measured using a spectrophotometer immediately after curing and at 1 day, 1 month, 3 months, 6 months, and 1 year, with and without a white background.

Main Results:

• Delta E*ab values generally increased for all shades up to 6 months, indicating color change.
• Color changes continued between 6 months and 1 year, with some shades showing increases and others decreases.
• One-month specimens exhibited delta E*ab over 1.2, while one-year specimens were near or over 2.5, suggesting noticeable color shifts.

Conclusions:

• Silux Plus composite resins exhibit color changes over a one-year period.
• The rate and direction of color change can vary between shades and over time.
• These findings have implications for the long-term aesthetic predictability of dental restorations using this material.