IADR Abstract Archives
Optical Properties of Resin Composite with Structural Coloration
Objectives: Spherical particles smaller than the wavelength of visible light can generate inherent structural color in dental resin composites (RBCs), without incorporating additional pigmentation. “OMNICHROMA” includes around 260 nm spherical filler and shows yellowish to reddish structural color close to tooth color. The aim of this study was to compare the optical properties of OMNICHROMA to universal shade of three commercial RBCs with additional pigmentation.
Methods: The following four RBCs were used: OMNICHROMA (OC, Tokuyama Dental, RBC with structural coloration), Tetric EvoCeram (TE, shade: T, Ivoclar Vivadent), Admira Fusion x-tra (AF, shade: U, VOCO GmbH), Essentia (ES, shade: U, GC). 1.0 mm thick specimens were made in 7.0 mm diameter molds. Each composite was light-cured for 20 seconds (Optilux LCT, Kerr; 10 mm tip, 500 mW/cm2). Spectral reflectance of each specimen from 380 to 780 nm was measured on a black background (n=3) with spectrophotometer (D65 illuminant; TC-1800MKII, Tokyo Denshoku). The color data of each specimen was measured on black and white background (n=3).
Results: As shown in Fig.1, OC showed maximum reflectance around 650 nm (yellow to red range). Other RBCs showed maximum reflectance around 450 nm (blue range). In response to these results, TE, AF and ES showed negative b* value on a black background because of low reflection around yellow to red range (Table.1). OC showed positive b* value on a black background. All four RBCs showed positive b* value and high L* value on a white background.
Conclusions: Optical property of RBC with structural coloration was different from other RBCs. Specifically, when the background was black (dark), OC with structural coloration maintained yellowish to reddish color and other RBCs showed negative b* meaning that they might look blue. These results indicate that color compatibility with dark shade of tooth is different between OC and other RBCs.
Methods: The following four RBCs were used: OMNICHROMA (OC, Tokuyama Dental, RBC with structural coloration), Tetric EvoCeram (TE, shade: T, Ivoclar Vivadent), Admira Fusion x-tra (AF, shade: U, VOCO GmbH), Essentia (ES, shade: U, GC). 1.0 mm thick specimens were made in 7.0 mm diameter molds. Each composite was light-cured for 20 seconds (Optilux LCT, Kerr; 10 mm tip, 500 mW/cm2). Spectral reflectance of each specimen from 380 to 780 nm was measured on a black background (n=3) with spectrophotometer (D65 illuminant; TC-1800MKII, Tokyo Denshoku). The color data of each specimen was measured on black and white background (n=3).
Results: As shown in Fig.1, OC showed maximum reflectance around 650 nm (yellow to red range). Other RBCs showed maximum reflectance around 450 nm (blue range). In response to these results, TE, AF and ES showed negative b* value on a black background because of low reflection around yellow to red range (Table.1). OC showed positive b* value on a black background. All four RBCs showed positive b* value and high L* value on a white background.
Conclusions: Optical property of RBC with structural coloration was different from other RBCs. Specifically, when the background was black (dark), OC with structural coloration maintained yellowish to reddish color and other RBCs showed negative b* meaning that they might look blue. These results indicate that color compatibility with dark shade of tooth is different between OC and other RBCs.
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