Related Experiment Video
Updated: May 13, 2026

Evaluating the Effects of Different Polishing Methods on Color Stability of Dental Restorations in Pediatric Dentistry
Published on: June 6, 2025
The influence of polymerization conditions on color stability of three indirect composite materials
Hideyuki Imai1, Hiroyasu Koizumi, Keiichi Sasaki
1Dental Technician Training School, Nihon University School of Dentistry, Tokyo, Japan. imai.hideyuki@nihon-u.ac.jp
Abstract:
The aim of the present study was to evaluate color change and color stability against aqueous media of three indirect composite materials (Epricord, Estenia, and Twiny) that were polymerized with different systems. Disk-shaped specimens were prepared with their proprietary polymerization systems or with a metal halide light polymerization unit (Twinkle X). The specimens were then immersed in water or tea. Change in color from baseline (24 h) to 4 weeks was determined with a chromameter (ShadeEye NCC) using a white background. The L*, a*, and b* values for both states were determined, and ΔE*(ab) values were calculated. The Estenia specimens immersed in tea had significantly lower ΔL* (-7.0 to -5.6) and significantly higher ΔE*(ab) values (6.5 to 8.6) than did the Epricord and Twiny specimens, under all polymerization conditions. The results indicate that after tea immersion the Estenia material was less stable against color change than were the other two materials. The Twinkle X metal halide unit was suitable for polymerization of the three composite materials, using an exposure period of 60 s or longer.
Related Concept Videos
Polymer Classification: Stereospecificity
Step-Growth Polymerization: Overview
Many natural and synthetic polymers are produced by...
Polymers
Polymer Classification: Architecture
Determination of Molar Masses of Polymers I
Characteristics and Nomenclature of Copolymers
