Discolorarion of Resin Composites After Immersion in Different Oriental Foodstuffs

Objectives:  The discoloration of restoratives is esthetic problem in clinical situation. The purpose of this study was to examine the discoloration of resin composites after immersion in different oriental foodstuffs.

Methods: Three types of resin composite restorative materials; Filtek Supreme Plus Restorative (SUP: nano-hybrid type, 3M ESPE), Clearfil AP-X (APX: semi-hybrid type, Kuraray medical) and Solare (SOL: MFR type, GC) were used. Composite was filled in a silicone mold (diameter of 20.0mm, thickness of 3.0mm) and irradiated with a halogen curing light source (Optilux501; Demetron). Cured specimens were polished with a series of SiC paper up to 2000 grit. The baseline measurement of the CIE-L*a*b* color was obtained using a colorimeter (CR-400, Konica minolta). 48 specimens were divided into four groups and were immersed in foodstuffs at 37 °C, distilled water (W: Taiyo Med), soy sauce (S: Kikkoman), perilla drink (P: Kisyu Kumano) and black vinegar (V: Kewpie). After 2 weeks of immersion, the specimens were rinsed with distilled water and then measured using colorimeter. The color differences (delta E*ab) were calculated and analyzed using two-way ANOVA and q-test (n=4).

Results: Color changes (delta E*ab) were SUP-W: 0.34±0.32, SUP-S: 0.57±0.33, SUP-P: 3.12±1.53, SUP-V: 0.92±0.18, APX-W: 0.41±0.18, APX-S: 0.98±0.29, APX-P: 0.51±0.36, APX-V: 0.54±0.30, SOL-W: 0.72±0.64, SOL-S: 0.81±0.58, SOL-P: 0.51±0.30, SOL-V: 0.64±0.19 (mean ± S.D.). Each of the factors (foodstuff, composite) was a statistically significant factor (p<0.01) and also there was an interaction with another factor (p<0.01). Color change after immersion in P was higher than that in W (p<0.01) and V (p<0.05). And also SUP showed the highest color change than that of APX and SOL (p<0.05).

Conclusions: Color of immersed resin composite was influenced by the types of foodstuff and resin composite in this study. It seemed that the filler contents of composite and the polyphenol of foodstuff influenced discoloration.