Esthetic restorative material shade changes due to photopolymerization

Area of Science:

• Dental Materials Science
• Color Science in Dentistry
• Polymerization Chemistry

Background:

• Accurate shade matching is crucial for aesthetic dental restorations.
• Polymerization of dental restorative materials can alter their color properties.
• Understanding color stability is essential for long-term clinical success.

Purpose of the Study:

• To quantify color changes in A1 shade dental restorative materials after photopolymerization.
• To compare the color stability of different types of dental restorative materials (resin composites, flowable resin composites, resin-modified glass ionomers).
• To assess color differences between polymerized materials and a standard tooth shade guide.

Main Methods:

• Measurement of L*a*b* color values using a spectrophotometer before and after photopolymerization under D65 illumination.
• Calculation of color differences (DeltaE*ab) using the CIE Lab color-difference formula.
• Statistical analysis (ANOVA, Newman-Keuls) to compare color changes among eight resin composites, three flowable resin composites, and two resin-modified glass ionomers.

Main Results:

• Photopolymerization induced color changes (DeltaE*ab) ranging from 3.01 to 17.76.
• Resin-modified glass ionomers and two flowable resin composites showed significantly greater color changes than resin composites (p < 0.05).
• Yellow-blue (b*) values decreased, while red-green (a*) values generally increased post-polymerization. Color differences among polymerized A1 materials ranged from 0.76 to 25.41 DeltaE*ab.

Conclusions:

• Photopolymerization significantly impacts the color of A1 shade dental restorative materials.
• Resin-modified glass ionomers and flowable resin composites exhibit less color stability compared to conventional resin composites.
• Clinicians should consider the potential color shifts of restorative materials for predictable aesthetic outcomes.