Influence of the association of over-the-counter bleaching agents on color change and microhardness of dental enamel

Abstract

This study will evaluate the efficacy of the over-the-counter bleaching agents combined in the dental bleaching and their influence on the microhardness of tooth enamel. One hundred and twenty bovine tooth specimens (6mm high x 6mm wide x 2mm thickness) will be made and then color (Easyshade, VITA ®, Bad Säckingen, Germany) and microhardness (Shimadzu, Tokyo, Japan) readings will be performed. Half of the specimens will be submitted to bleaching using 22% Carbamide peroxide (Whiteness Perfect 22, FGM). Beached and not bleached fragments will be randomly separated into 12 groups (n=10) according to the bleaching agents that will be submitted: Toothpaste (Whitening - Colgate Luminous White; Regular - Sorriso Dentes Brancos; Whitening with hydrogen peroxide in the composition - Advance White) and Mouthwash (Whitening - Colgate Luminous White and Regular - Colgate Plax Classic). The toothbrush (Pepsodent, MAVTEC - Com. Parts, accessories and Serv. Ltda. ME, Ribeirão Preto, SP, Brazil) and the immersion in mouthwash will be simulated corresponding to one year of using the bleaching agents. After the treatments, final color and microhardness readings will be done. Quantitative data will be collected; normality will be checked by the Kolmogorov-Smirnov test, and statistical tests will be applied according to data distribution. (AU)