IADR Abstract Archives
Color Adaptation at Enamel-composite Borders With Different Incident-light Directions
Objectives: The purpose of this study was to investigate effect of incident-light directions (from composite or enamel side) on color adaptation at coronal- and cervical-enamel borders of composite restorations.
Methods: Forty cylindrical punched cavities (3.0 mm diameters) were prepared in bovine enamel disks (1.0 mm thickness). After applied with a one-step self-etch adhesive (Clearfil SE One), one of four resin composites (Estelite Asteria, EA; Tokuyama Dental, Estelite Pro, EP; Tokuyama Dental, Kalore, KA; GC America and Clearfil Majesty ES-2 Premium, MJ; Kuraray Noritake) was restored in the cavity. After 24 hours storage, the colors (L*, C*, or h* values) at the restored enamel disks with resin composites were measured in 100% relative humidity over a black background using a CIE XYZ camera (RC500, PaPaLaB Co., Japan), spotted with D65 standard illuminant from coronal or cervical side at 45/0-degrees geometry in a black box. The color shifting rate and range were calculated at the coronal- and cervical-enamel borders of composite restoration, and analyzed by three-way ANOVA with Dunnett’s T3 and t-test for post hoc analysis (p<0.05).
Results: The incident-light direction affected the L* shifting rate at the cervical-enamel border in EP and MJ (p<0.05), but not in EA and KA (p>0.05). On the other hand, at the coronal-enamel border, the L* shifting rate in all the composite materials was not affected by the incident-light direction (p>0.05). Additionally, the incident-light direction did not affect the L* shifting range at both enamel borders in all the composite materials (p>0.05).
Conclusions: Line-of-vision angle would affect the appearance of color adaptation at the cervical-enamel border of composite restoration, which was dependent upon the composite materials. On the other hand, at the coronal-enamel border, the line-of-vision angle would not affect the color adaptation.
Methods: Forty cylindrical punched cavities (3.0 mm diameters) were prepared in bovine enamel disks (1.0 mm thickness). After applied with a one-step self-etch adhesive (Clearfil SE One), one of four resin composites (Estelite Asteria, EA; Tokuyama Dental, Estelite Pro, EP; Tokuyama Dental, Kalore, KA; GC America and Clearfil Majesty ES-2 Premium, MJ; Kuraray Noritake) was restored in the cavity. After 24 hours storage, the colors (L*, C*, or h* values) at the restored enamel disks with resin composites were measured in 100% relative humidity over a black background using a CIE XYZ camera (RC500, PaPaLaB Co., Japan), spotted with D65 standard illuminant from coronal or cervical side at 45/0-degrees geometry in a black box. The color shifting rate and range were calculated at the coronal- and cervical-enamel borders of composite restoration, and analyzed by three-way ANOVA with Dunnett’s T3 and t-test for post hoc analysis (p<0.05).
Results: The incident-light direction affected the L* shifting rate at the cervical-enamel border in EP and MJ (p<0.05), but not in EA and KA (p>0.05). On the other hand, at the coronal-enamel border, the L* shifting rate in all the composite materials was not affected by the incident-light direction (p>0.05). Additionally, the incident-light direction did not affect the L* shifting range at both enamel borders in all the composite materials (p>0.05).
Conclusions: Line-of-vision angle would affect the appearance of color adaptation at the cervical-enamel border of composite restoration, which was dependent upon the composite materials. On the other hand, at the coronal-enamel border, the line-of-vision angle would not affect the color adaptation.