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Background/purpose The primeval evaluation of the properties of composite resins with different compositions that impact clinical behavior is very important in guiding use in clinical settings. The aim of this study was to evaluate color stability (ΔE) and Knoop microhardness (KHN) of composite resins containing different compositions. Materials and methods Forty-five disks were made composite resins: Filtek Z350 XT/3MESPE and Beautifill II/SHOFU and divided into 3 subgroups: Control - immersed in artificial saliva; OB – brushing with Oral B 3D White; CT - brushing with Colgate Total 12. The OB and CT groups had the disks brushed daily with 120 cycles after immersion in coffee solution (10 min) for a period of 30 days. ΔE and KHN was obtained at baseline and after the treatments. Data were analyzed ANOVA and Tukey tests ( p < 0.05). Results ANOVA revealed significant differences for ΔE and KHN. ΔE: the highest mean was observed in Beautifil II composite resin group, which differed significantly from Z350 group. For the Beautifil II, the treatments were significantly different from each other. For the Z350, the control group showed significant differences in relation to OB e CT groups. KHN: the highest mean was observed in Z350 group, which differed significantly from Beautifil II group. For Z350, the control group showed significant differences in relation to OB e CT groups. For Beautifil II, the treatments did not differ significantly among themselves. Conclusion The composite resin containing fluoride in the composition showed higher color alteration (ΔE) and lower Knoop microhardness (KHN), thus demonstrating that composition is an important factor in the clinical performance of esthetic restorative materials.

ABSTRACT:The aim of this study was to evaluate the effects of ultraviolet artificial aging on color, fluorescence, gloss, and translucency of different composite resins. Seventy-five cylindrical-shaped specimens (6 mm in diameter and 1 mm thick) of four different composites: Admira Fusion (VOCO), TPH3 (DENTSPLY), GrandioSO (VOCO) and Filtek™ Z350 XT (3M/ESPE), were built. Enamel samples obtained from bovine incisors were prepared with the same dimensions and used as a control group. Assessments of color, translucency, fluorescence, and gloss were performed at baseline and after artificial aging. Specimens were immersed in artificial saliva and submitted to artificial aging (UV light for 300h). Data were analyzed using one-way ANOVA and Tukey's post hoc test (α=0.05). After aging, all resin composites presented significant alterations, mainly Filtek™ Z350 XT. Fluorescence decreased in all resin composites and enamel. Gloss was reduced in all groups, too, with major rates for TPH3 and GrandioSO, which was similar to the enamel reduction. Translucency did not present a significant difference for the resin composites, although there was a reduction in the enamel. After artificial aging resin composites became darker, less fluorescent, less glossy, and with no alteration in translucency.

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Objectives: To evaluate the effect of bleaching on colour, gloss, translucency, and microhardness of two types of resin composites (Charisma Classic and Filtek Z350 XT), previously aged. Materials and methods: Forty specimens of each material were artificially aged for 300 hours (UV-accelerated aging). Specimens were then treated with 35% hydrogen peroxide (Whiteness HP) in four 15-minutes sessions, totaling one hour of bleaching. Colour coordinates CIE L*a*b* and parameters of translucency (PT) were measured using a spectrophotometer (CM2600d-Konica Minolta), surface gloss readings were performed with a glossmeter (Novo-Curve-Rhopoint TM), and microhardness was assessed using a hardness device (FM-700, Future-Tech). Measurements have been performed after artificial aging as well as after the first and last bleaching protocol. Data were analyzed by two-way ANOVA and two-way repeated measures ANOVA, followed by Tukey's test (5%). Results: The bleaching procedures of aged resin composites decreased the gloss and increased the translucency, but did not alter colour and microhardness. Conclusion: Bleaching procedures should be used carefully when resin composite restorations are present.