Calculation of colour resulting from composite/compomer layering techniques.

Area of Science:

• Dental Materials Science
• Optical Properties of Materials
• Colorimetry

Background:

• Aesthetic dental restorations require precise color matching.
• Understanding the optical behavior of layered materials is crucial for predicting final restoration color.
• Current methods for predicting layered material color are limited.

Purpose of the Study:

• To determine how optical properties of constituent layers influence the color of double-layer aesthetic filling materials.
• To develop regression equations for predicting the color of layered materials.
• To identify key optical parameters affecting the final color.

Main Methods:

• Prepared double-layered specimens using light-cured resin composites and a compomer.
• Measured Commission Internationale de I'Eclairage (CIE) L*, a*, b* values using a spectrophotometer.
• Calculated scattering coefficient (S), absorption coefficient (K), contrast ratio (C), and translucency parameter (T).
• Utilized forward regression analysis to correlate optical values of individual layers with the layered material's color.

Main Results:

• CIE L* of layered material correlated positively with the scattering coefficient (S) of the covering layer.
• CIE a* and b* of layered material showed strong correlations with the respective a* and b* values of the covering layer.
• The regression equations derived could predict the layered color of these materials within study limitations.

Conclusions:

• The optical properties of the covering layer significantly influence the final color of double-layer aesthetic filling materials.
• Scattering coefficient (S) of the covering layer is a key factor for predicting lightness (L*).
• Color parameters (a*, b*) of the covering layer are primary determinants for the final a* and b* values.