Influência da concentração de peróxido de hidrogênio nos agentes clareadores na cor e penetração através da estrutura dental

• Ano de defesa: 2014
• Autor(a) principal: Godoy, Monique Martins Maia [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Peróxido de hidrogênio; Clareadores dentários; Cor na odontologia; Hydrogen peroxide
• Link de acesso: http://hdl.handle.net/11449/124110; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/18-05-2015/000828156.pdf

The aim of this study was to evaluate the effects of bleaching agents on colour and the penetration of the hydrogen peroxide throughout the dental structure. One hundred cylindrical samples of enamel/dentin, obtained from bovine incisors, were prepared with 6mm of diameter and 2mm of thickness (n=20). The samples were divided into five groups, according to the concentration of hydrogen peroxide contained in bleaching gels eemployed: 20%; 25%; 30%; 35%; 40%. The samples were positioned over the artificial pulpar chambers containing an acetate buffer solution and the bleaching was performed for 30 minutes. A sample of the solution was collected and the concentration of the peroxide was measured by a spectrophotometer. To analyse the bleaching effectiveness, the chromatic coordinates Lab were measured, beforehand and one week later the bleaching procedure. The data were analysed by using the analysis of variance (ANOVA) and Tukey's test at a significance level of 5% (0.05). The mean value (+-dp) and the results of Tukey's test to hydrogen peroxide penetration were: 20%: 4.32 (±1.93) a, 25%: 4.33(±1.75) b, 30%: 6.42 (±2.64) c, 35%: 8.44 (± 3.03) d, 40%: 8.64 (±3.09) e. The results for color change were for ΔL: 20%: 2.47 (± 1.32) a, 25%: 2.55 (± 0.64)b, 30%: 2.78 (± 0.90)c, 35%: 3.30 (± 0.96)d, e 40%: 3.33 (± 1.56)e. for Δa: 20%: -0.60 (± 0.66) a, 25%: -0.71 (± 0.37) b, 30%: -0.87 (±0.42) c, 35% -0.96 (± 0.55) d, 40%: -1.09 (± 0.61) e. For Δb: 20% -3.18 (± 1.57) a, 25%: - 3.44 (± 1.17) b, 30%: -3.77 (± 1.39) c, 35%: -5.28 (± 1.42) d and 40%: -5.35 (± 1.38) e. For ΔE: 20%: -3.18 (± 1.57) a, 25%: -3.44 (± 1.17) b, 30%: -3.77 (± 1.39) c, 35%: - 5.28 (± 1.42) d, and 40% -5.35 (± 1.38) e. The groups followed by the same letter do not present significant differences. It was concluded that the increasing of peroxide concentration enhanced bleaching effect, but also increased the penetration through the tooh structure