Publications by authors named "Marcus V Araujo"
Introduction: The aim of this study was to evaluate colour alteration of transparent elastic ligatures submitted to exogenous pigmentation.
Methods: Forty test specimens were divided into eight groups corresponding to one commercial brand with five test specimens in each group. The test specimens were immersed into coffee and black tea solutions with the purpose of assessing colour alteration using a portable digital spectrophotometer (Vita Easyshade Compact).
Background: The colour stability of aesthetic brackets may differ according to their composition, morphology and surface property, which may consequently influence their aesthetic performance.
Aims: To assess the colour stability of aesthetic brackets (ceramic and plastic) after simulating aging and staining.
Methods: Twelve commercially manufactured ceramic brackets and four different plastic brackets were assessed.
Objectives: The aim of this study was to assess, in vitro, the color of teeth exposed to different mouthrinses for a prolonged period.
Methods: Bovine teeth were distributed in four groups: control, alcohol-containing mouthrinse (Listerine(®)), alcohol-free mouthrinse (Oral-B(®)) and chlorhexidine mouthrinse (Periogard(®)). The teeth were submitted to two cycles of staining and artificial aging.
Objectives: The aim of this study was to assess the optical properties of orthodontic elastic ligatures under the influence of exogenous pigments contained in the daily diet.
Material And Methods: For the analysis, colorless (clear) elastic segments (ORTHO Organizers, lot 660625A10) were used as received from the manufacturer, and were divided into 8 groups of 3 segments each. Each group was immersed in 200 mL of a solution containing a determined substance, as follows: distilled water (control group), Coca-Cola®, Pomarola brand tomato sauce (Cica®), açai, Jasmine® brand green tea, Royal Blend® black tea brand, Pilão® brand coffee and Palmares® wine brand.
Objective: To evaluate the color stability of six esthetic archwires at different time periods and their fluorescence.
Materials And Methods: Samples were evaluated after 7, 14, and 21 days of immersion in staining solution. Color measurements were performed by means of a spectrophotometer according to the Commission Internationale de I'Eclairage L*a*b* system, and color changes (ΔE*) and National Bureau of Standards units were computed.
Introduction: The aims of this study were to evaluate the optical properties of esthetic brackets and determine their influence on visual perception.
Methods: Eighty esthetic brackets of 16 commercial brands were tested. The color and translucency of the brackets, as well as the color of the maxillary central incisors of 40 subjects, were measured with a spectrophotometer.
Objective: To test the null hypothesis that it is not possible to incorporate metal ions arising from orthodontic appliance corrosion into tooth enamel with resulting tooth color change.
Materials And Methods: This in vitro study used atomic absorption spectrophotometry to evaluate the presence of nickel, chromium, and iron ions in tooth enamel in three groups: a group submitted to cyclic demineralization and remineralization processes with solutions in which orthodontic appliances were previously immersed and corroded, releasing metallic ions; a control group; and another group, submitted to cycling only, without the presence of orthodontic appliances. The influence of the incorporation of these metals on a possible alteration in color was measured with a portable digital spectrophotometer using the CIE LAB system.