1Student, Department of Restorative Dentistry, Institute of Science and Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
2Assistant Professor, Department of Restorative Dentistry, Institute of Science and Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
3Associate Professor, Department of Restorative Dentistry, Institute of Science and Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
*Correspondence: Dr. Carlos Rocha Gomes Torres. Av. Eng. Francisco José Longo, 777, São José dos Campos, SP, Brazil. Tel.: +55-(0)12-39479376; Fax: +55-(0)12-39479010; Email: carlosrgt@fosjc.unesp.br.
Online published on 18 January, 2019.
The aim of this study was to evaluate the influence of temperature on the bleaching efficacy of hydrogen peroxide on chromogenic solutions from wine and tobacco.
Inside optical glass cuvette, equal amounts of chromogenic solution (wine or tobacco), hydrogen peroxide 60% and ultra-pure water were mixed. Initial color readings were performed with a reflectance spectrophotometer immediately after mixing. Samples of the solutions were subjected to predetermined temperatures (5, 10, 15, 20, 25, 30, 35, 40, and 45°C). After 10 min of reaction for the wine chromogenic solution and 20 min for tobacco chromogenic solution, a final color reading was performed for each sample solution, and the value of the general color variation (ΔE) was calculated. Data were statistically analyzed by one-way analysis of variance and Tukey's test (5%).
There was a significant effect of temperature on color variation of tobacco and wine solutions. The ΔE values for the wine, at temperatures of 40–45°C, and tobacco solution, at a temperature of 45°C were statistically higher than those obtained at other temperatures.
The temperature positively influenced the bleaching effect of hydrogen peroxide, resulting in more effective bleaching at higher temperatures. The investigation of the ideal temperature for the highest efficacy of hydrogen peroxide reaction can contribute for the improvement of the bleaching outcomes.
Bleaching, hydrogen peroxide, spectrophotometry, temperature
