Discoloration of auto-polymerized resin applied using a brush-on technique

抄録

Purpose: The discoloration of auto-polymerized resin has frequently been observed after denture repair. This study is an investigation of the discoloration of auto-polymerized resin applied using a brush-on technique.
Materials and Methods: Rectangular resin plates were fabricated so that five auto-polymerized resins (Unifast II, Unifast Trad, Provinice, Metafast, and Miky) could be packed in a mold (15x30x1 mm) using a brush-on technique (resin brush, horsehair) in six increments for each mold. As controls, the five resins were poured in the molds after the polymer and monomer were mixed at 0.5 mL/g for 10 s. After polymerization, half of the resin plates were covered with aluminum foil. All the plates were soaked in distilled water (37°C) and exposed to xenon light for 24 hours according to ISO 7491. They were soaked in water again for 5 days. After removing the aluminum foil, the discoloration was measured using a color difference meter (Shade eye system) three times for each specimen. The color differences (∆E: n=5) were analyzed by ANOVA/Tukey’s test (α=0.05).
Results: For the brush-on technique, Provinice had the greatest color change of any of the resins tested. There were significant differences between the brush-on technique and the controls for Unifast II and Miky.
Conclusion: The brush-on technique resulted in fewer color changes than the mixing technique on all resins except for Provinice, as shown by the fact that many porosities were found in the control specimens.