Oral Biol Res.  2023 Dec;47(4):123-131. 10.21851/obr.47.04.202312.123.

Staining of restorative composite resins at various light curing times

• Woo J
• Kim SJ

• KMID: 2550103
• DOI: http://doi.org/10.21851/obr.47.04.202312.123

Abstract

This study aimed to assess the relationship between different degrees of conversion attained by different curing times and color change of composite resins. Disc-shaped specimens (2.0 mm in thickness and 8.0 mm in diameter) were made from two types of composite resins (Filtek Supreme Ultra and Tetric EvoCeram) with four different light curing times (5, 10, 15, and 20 sec). The degree of conversion was measured using Fourier transform infrared spectroscopy. Specimens were immersed in three solutions (water, coffee, and red wine) for 4 and 24 weeks. Color was measured by spectrophotometry (CM-700d), and the color differences (ΔE 00 ) were calculated. The difference in the degree of conversion according to different curing times were statistically significant and showed positive correlations (p<0.05). The degree of conversion and color change showed statistically significant negative correlation with Filtek Supreme Ultra and Tetric EvoCeram when aged in staining solutions: at 4 weeks, Filtek in wine (β=−0.648, R² =0.420, p=0.002), Filtek in coffee (β=−0.560, R² =0.314, p=0.01), Tetric in wine (β=−0.896, R² =0.804, p<0.001), and Tetric in coffee (β=−0.859, R² =0.738, p<0.001); at 24 weeks, Filtek in water (β=−0.594, R² =0.353, p=0.006), Filtek in wine (β=−0.656, R² =0.430, p=0.002), Filtek in coffee (β=−0.740, R² =0.548, p<0.001), Tetric in wine (β=−0.799, R² =0.639, p<0.001), and Tetric in coffee (β=−0.596, R² =0.738, p=0.006). A sufficient light curing time is needed for better color stability of composite resins exposed to common staining agents such as coffee and red wine.

Keyword

Composite resin; Degree of conversion; Discoloration; Staining