Sérgio Roberto Costa Vieira

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The purpose of this study was to evaluate the shear bond strength of resin-modified glass ionomer cement in a saliva-contaminated environment, using different enamel pretreatments. A total of 125 freshly extracted, bovine permanent inferior incisors were divided into five groups. Group I received 10% polyacrylic acid, moistened with saliva/Fuji Ortho LC(More)
OBJECTIVE The aim of this study was to establish the reaction kinetics of 35% hydrogen peroxide and sodium ascorbate and to determine the mass of antioxidant required to neutralize the bleaching gel. METHODS The method used to quantify sodium ascorbate was based on the United States Pharmacopeia (1995)(26). Oxidation-reduction titration was used to(More)
PURPOSE To evaluate the tensile bond strength of indirect composites repaired with different surface treatments and direct composites. METHODS 180 specimens were prepared with Targis, belleGlass HP and Sculpture indirect composites, light-activated and post-cured according to the manufacturers' recommendations. The specimens were stored in distilled water(More)
BACKGROUND The authors conducted a study to evaluate the stain removal ability of tooth bleaching and simulated toothbrushing after coffee and cigarette smoke staining and to determine the enamel susceptibility to restaining. METHODS The authors used a colorimeter to determine the baseline color of 40 bovine labial enamel surfaces according to the(More)
This study quantitatively evaluated the fluorescence intensity of resin composites with different opacities and translucencies and determined changes in fluorescence after accelerated aging, using human enamel and dentin as controls. Six microhybrid and nanofilled composites, each in three different shades, were tested. Ten sound human incisors were used to(More)
AIM The objective of this study was to evaluate the effect of light polymerization on water sorption and solubility of hybrid composites. METHODS AND MATERIALS Three composite resins were used to make discs cured with either quartz-tungsten halogen (QTH) or light emitting diode (LED) curing units. The specimens were stored in a desiccator at 37 degrees C(More)
OBJECTIVES To assess in situ the effect of different restorative techniques used with fluoride-releasing materials on enamel and dentine demineralization in the presence of a cariogenic challenge. METHODS Thirty human molars were prepared for 60 Class V cavities, with enamel and dentine margins. The teeth were divided into four groups (n=15): L1 - open(More)
OBJECTIVES Colour changes of the luting material can become clinically visible affecting the aesthetic appearance of thin ceramic laminates. The aim of this in vitro study was to evaluate the colour stability and opacity of light- and dual-cured resin cements and flowable composites after accelerated ageing. METHODS The luting agents were bonded (0.2 mm(More)
The aim of this study was to determine the pH of several commercially available in-office and at-home dental bleaching products stored at room temperature and refrigerated. The products were divided into in-office (n=09) and at-home (n=12) bleaching gels and submitted to two different temperatures, namely, room temperature (23 degrees C +/- 1 degree C) and(More)
The aim of this study was to evaluate, in vitro, frictional forces produced by ceramic brackets and arch wires of different alloys. Frictional tests were performed on three ceramic brackets: monocrystalline (Inspire ICE), polycrystalline (InVu), polycrystalline with metal slot (Clarity), and one stainless steel bracket (Dyna-Lock). Thirty brackets of each(More)