Difference in the color stability of direct and indirect resin composites.
ABSTRACT Indirect resin composites are generally regarded to have better color stability than direct resin composites since they possess higher conversion degree.
The present study aimed at comparing the changes in color (ΔE) and color coordinates (ΔL, Δa and Δb) of one direct (Estelite Sigma: 16 shades) and 2 indirect resin composites (BelleGlass NG: 16 shades; Sinfony: 26 shades) after thermocycling.
Resins were packed into a mold and light cured; post-curing was performed on indirect resins. Changes in color and color coordinates of 1-mm-thick specimens were determined after 5,000 cycles of thermocycling on a spectrophotometer.
ΔE values were in the range of 0.3 to 1.2 units for direct resins, and 0.3 to 1.5 units for indirect resins, which were clinically acceptable (ΔE<3.3). Based on t-test, ΔE values were not significantly different by the type of resins (p>0.05), while ΔL, Δa and Δb values were significantly different by the type of resins (p<0.05). For indirect resins, ΔE values were influenced by the brand, shade group and shade designation based on three-way ANOVA (p<0.05).
Direct and indirect resin composites showed similar color stability after 5,000 cycles of thermocycling; however, their changes in the color coordinates were different.
- SourceAvailable from: Panagiotis E Lagouvardos[show abstract] [hide abstract]
ABSTRACT: The purpose of this study was to investigate the effect of different staining solutions on the color coordinates of indirect light-cured resin composites. 112 discs were made using four indirect composites, Signum+/Haraeus-Kulzer, Sinfony/3M-Espe, GC Gradia/GC, Ena HRi/Micerium, and divided into four groups which immersed in tea, coffee, chocolate and distilled water, at 37 °C, for 4 weeks. The color, before and after immersion for 1, 2, 3 and 4 weeks, was measured according to CIELAB system and ΔL*, Δa*, Δb* and ΔE* values were calculated for all immersion periods. The effect of time, solution and material on primary and secondary color coordinates was estimated using two-way repeated ANOVAs and pairwise comparisons, at a = 0.05. The results showed that coffee strongly affected all the materials (p < 0.05), followed by tea and chocolate. Sinfony presented the highest color change (p < 0.05), due to changes in b* and L* coordinates. Color coordinates were affected differently by material type and solution. In conclusion, this study showed that the color of indirect resin composites was affected by all three examined factors (immersion time, staining solution and material type), in a clinically appreciable level (ΔΕ* > 2.7 U) even from the first week, and in an unacceptable level (ΔΕ* > 5.5 U) in the second, third and fourth week, depending on the staining solution and the material.Odontology 02/2013; · 1.58 Impact Factor
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ABSTRACT: To correlate the DIAGNOdent readings (LF) with those of direct visual (DV) examination, indirect visual (IDV) examination, bitewing radiography (BWR), and pit and fissure opening (PFO) for the detection of occlusal caries in primary teeth; to determine the validity of this device using PFO as reference; and to evaluate its reliability. Two calibrated operators examined 130 teeth with 405 examination sites using DV, IDV and radiographic examinations, and LF. Of the 405 sites, 155 were visually scored for caries after pit and fissure opening. Pit and fissure opening was found to significantly correlate with all methods (rhoLF = 0.48, rhoBWX = 0.48, rhoDV = 0.44, rhoIDV = 0.41). For enamel lesions, higher sensitivity (0.76) was found with DV, while higher specificity (0.88) with the LF. For lesions into dentin, however, higher sensitivity (0.78) was found with the LF, while higher specificity (0.98) with the BWR. The device's accuracy was found to be 0.61 for enamel lesions, while for lesions into dentin 0.70, and its reliability was excellent (ICC = 0.97). The LF device presented high reliability in the detection of occlusal caries in primary teeth and its performance was similar to DV and radiographic examinations.International Journal of Paediatric Dentistry 06/2008; 18(3):197-204. · 0.92 Impact Factor