IADR Abstract Archives
Heating Effect Upon the Color Coordinates of Composite Resins
Objectives: To evaluate the color changes of 3 composite resins (2 universal and 1 microhybrid) after one cycle of heating.
Methods: A total of 84 disks (n=14) (diameter 10 mm, thickness 1 mm) were manufactured from 2 universal composites (Omnichroma- Tokuyama and Optishade universal MD – KavoKerr) and 1 microhybrid composite, (Biofunction Enamel Plus Hri, Micerium). From the total number, half of the specimens were made from unheated composite, the other half were fabricated after the composites were subjected to heating (45 oC, 1h, Ease-it, Ronvig).
The specimens were incrementally built (Porcelain sampler, SmileLine), polymerized on both sides (Woodpecker Led. H Orto), and immersed (24 h) in distilled water.
The color coordinates (L*, a*, b*) have been measured with a spectrophotometer (SpectroShade (MHT), with the samples placed on white, black, and grey background.
Differences in color parameters ΔL*, Δa*, Δb*, color and translucency difference (DE00 and ΔTP00), and difference in whiteness index (ΔWID) between unheated and heated samples have been calculated.
Results: The calculated differences varied as follows: ΔL* -0.35 – 0.98; Δa*-0.27 – 0.0; Δb* -2.18 – 0.06; DE00 0.79 – 1,76; ΔTP -2.03 - -0.18, and ΔWid 0.02 – 3.54. In all cases, Omnichroma had the highest variations of the optical parameters.
Conclusions: One cycle of composite heating resulted in color and translucency differences; for the universal composite DE00 was situated between the perceptibility and acceptability thresholds.
Methods: A total of 84 disks (n=14) (diameter 10 mm, thickness 1 mm) were manufactured from 2 universal composites (Omnichroma- Tokuyama and Optishade universal MD – KavoKerr) and 1 microhybrid composite, (Biofunction Enamel Plus Hri, Micerium). From the total number, half of the specimens were made from unheated composite, the other half were fabricated after the composites were subjected to heating (45 oC, 1h, Ease-it, Ronvig).
The specimens were incrementally built (Porcelain sampler, SmileLine), polymerized on both sides (Woodpecker Led. H Orto), and immersed (24 h) in distilled water.
The color coordinates (L*, a*, b*) have been measured with a spectrophotometer (SpectroShade (MHT), with the samples placed on white, black, and grey background.
Differences in color parameters ΔL*, Δa*, Δb*, color and translucency difference (DE00 and ΔTP00), and difference in whiteness index (ΔWID) between unheated and heated samples have been calculated.
Results: The calculated differences varied as follows: ΔL* -0.35 – 0.98; Δa*-0.27 – 0.0; Δb* -2.18 – 0.06; DE00 0.79 – 1,76; ΔTP -2.03 - -0.18, and ΔWid 0.02 – 3.54. In all cases, Omnichroma had the highest variations of the optical parameters.
Conclusions: One cycle of composite heating resulted in color and translucency differences; for the universal composite DE00 was situated between the perceptibility and acceptability thresholds.